June 30, 2009
9:35 P.M.
Nothing new to talk about today. Tomorrow, I'll talk about pyrocumulus clouds. Without looking up the term, post what you think they are on the wall. I'll see how many people read this. :)
June 30, 2009
6:36 P.M.
So I actually wasn't able to talk to professor Mass today, but I did talk with a woman whose job it is to talk to undergrads and high schoolers about getting a degree in atmospheric sciences. It is going to be a lot of work, but I'm now even more interested in going into meteorology than ever before. And if I get a Phd, I have to go through 6 years of graduate school, but then I can hold a position similar to that of Cliff Mass. Then you guys can all be like, "I remember "Charlie's Weather Forecasts" and how smart and charming that geek was." Well a doctorate is a long way off, but as a junior in high school, I have my heart set on it and won't take this journey for granted.
The weather we can expect around here for the foreseeable future is warm and sunny in general. This coming week in particular looks outstanding.
We will have high pressure stationed over the area and a thermal troft will swing by the coast. This will help to generate offshore flow from the mountains down into the Puget Sound Lowlands, which will cause higher temperatures due to downslope adiabatic warming and drier air for the same reason (as air descends it compresses, warms, and dries). This will cause us to have beautiful blue skies and highs in the upper 70s to mid 80s for most of the week. Just in time for July 4th, the clouds will start to roll in, but we should remain dry. Highs over the weekend will reach the mid 70s.
By Monday, there will be more clouds and lower temperatures. Highs should reach the low 70s.
The reason for this increase in clouds and decrease in high temperatures is because the thermal troft will have passed to our east, ushering more onshore flow from the ocean. Obviously, the Pacific Ocean is cooler than the land in the summer and warmer in the winter, so in either season, it always moderates.
The extended looks like we will see normal or slightly above normal temperatures with mostly sunny conditions. Get outside and thanks for looking at the blog!
June 29, 2009
8:45 P.M.
I should let you guys know that I probably won't do many forecasts on weekends or Fridays, as I am usually out of town. The forecast generally looks the same. I'm talking to Cliff Mass tomorrow, so tomorrow I'll have a lot to write about.
June 25, 2009
6:04 P.M.
The prognosis is the same for the next couple days, I'm just writing here to let you know that I am alive and well. Have a good Thursday evening people.
June 24, 2009
7:12 P.M.
Those of you at the UW Jazz Camp got an explanation of the predicted weather pattern for the next two weeks. Well, for sun lovers, I have some good news. The ridge of high pressure that was keeping us semi-dry semi-wet now looks like it will strengthen more than originally thought. This will allow us to have weather in the mid 70s for the forseeable future. I am now calling for the same "boom chuck chuck" pattern, but I think we will only be waltzing with clouds as opposed to rain.
In the meantime, we had some showers today, and we will have more tonight. The Puget Sound Convergence Zone will form a little bity south of its usual location. Usually, the PSCZ hangs out in the Shoreline/Edmonds area, but tonight, it will drift southward into the Seattle metropolitan area. This means we will see a narrow band of fairly steady rain or frequent showers right around Seattle, with clear skies to the north and south of us. This convergence zone will linger into early Thursday morning before tapering off in the mid-morning hours.
June 23, 2009
7:03 P.M.
Hey everybody. Apologies for no forecast over the weekend; I was out of town digging clams, and Monday I spent all day cleaning them. But now they are cleaned and in the freezer. Contact me if you want some. They sell for as much as 30 dollars a pound in Japan for the whole clam (including shells and guts) but I will sell them to you for the low price of $14.99 per pound. Considering the fact that I have already cleaned them and sliced them up, this is a very, very good deal. Or maybe I'll just give them away for free. Depends on how much I like you, I guess.
But anyway, the weather we have had of late is fairly typical for early summer, albeit a bit cooler and wetter than normal. Scott Sistek actually quoted it as a "waltz" with one day being sunny, one day being a transition day between sun and rain, and the next being a rainy day. "Boom chuck chuck boom chuck chuck." You get the idea.
So how long will this pattern last for? It seems to be going on for a long time. This is because we have a weak ridge of high pressure in our area. It is enough to keep us fairly dry, but it can't block out all of the moisture that the Pacific has to offer. As for the rain arriving every three days, that is because the low pressure systems coming off the Pacific are coming in every three days or so.
Later, the weather looks like it will take a turn for the more traditional cloudy morning, sunny afternoon days with highs in the mid 70s to lower 80s. I can say with caution that the 4th of July should have good weather. But, it's the Fourth of July. Crazy weather events have always happened on that date. I'll tell you about some when our 233rd anniversary of our independence roles around.
June 19, 2009
2:11 P.M.
Man! The year went by fast, didn't it? I really felt like sophmore year blew right past me. I'm definitely happy it is summer though.
The last few weeks we have had some amazing weather. A week or so ago, highs hit 90. Today, it is much colder, and we finally got some rain last night to clean up the air (I was having really bad hay fever). This weekend, unfortunately for some but fortunately for those who want a longer respite from this recent hot weather, will be cool and showery. Saturday and Sunday will feature highs in the mid to upper 60s with lows in the low 50s. There will not be a threat of widespread rain, but there will be showers scattered around the Puget Sound Lowlands, especially toward the foothills and in the mountains (Cascades or Olympics). The atmosphere isn't particularly unstable though, so these showers should just be light sprinkles for the most part as opposed to dark ominous thunderstorms. Monday through Friday next week looks average for this time of year; highs in the low to mid 70s and lows in the low 50s. Often, we will see cloudy skies in the morning due to a "marine push" of air coming in (this is due to minute differences in pressure caused by uneven heating between Washington and the Pacific Ocean; the Pacific has a higher heat capacity and is slower to heat up or cool off than the land, so when the land (not the atmosphere) is warmest late afternoon into the night, there is lower pressure (warm air rises) and cool air from the ocean (which has relatively higher pressure) floods in to 'even out' the atmospheric pressure). This marine push will cause cloudy skies in the morning, but the sun will burn these off and we will have sunny afternoons. Have a great weekend everybody, and congratulations on finishing the 2008-2009 school year!
Thursday, October 7, 2010
February - May 2009 (Sporadic Forecasts)
May 12, 2009
9:18 PM
For some reason, the atmosphere failed to really destabilize, and the expected thundershowers failed to flare up. Tomorrow, in the plains, there will be a huge outbreak of severe weather. I suggest you read about it in the blogs on accuweather.com.
May 11, 2009
6:38 PM
Just like the passage of a contrail disintegrating into the atmosphere due to low relative humidity 37,000 feet up, the AP Euro exam has passed out of us sophomores lives. An anti-climatic climax it was, at least for me, as I could have done more useful things with my time then creating a 45-page outline of the entire year which I didn’t even use. Still, it is a testament to the prowess and power man possesses, which is still reminiscent of the Italian renaissance, especially in individualists such as Pico della Mirandola (Oration on the Dignity of Man).
But now I seriously need to get that stuff out of my life, and get back to weather. That is what this page is about. But still, weather has become a part of me so much that it’s almost difficult to distinguish what it is and what it isn’t. That’s why I ramble on things most people would find totally unrelated to weather. I see the resemblance, and I never erase any of my work. I just type as things come to me. And if you don’t like my approach, you can always look elsewhere. Q13 Fox! Oh joy! The pinnacle of forecasting, the very essence of the art. Yeah right. Q13’s weather is like the kid trying to nudge his head into a circle of kids having a conversation, with only his head being visible between the frames of others. Anyways……… yeah. Ok. Back to weather
I’m mainly looking forward to tomorrow. A cold area of low pressure is spinning due west off of our coast right now, and it is expected to track inland tomorrow. It is currently very weak, but what it will do is offer the cold air needed to spark off instability in the atmosphere. With the sun at a very high angle, the development of showers and thunderstorms will be rapid and swift. Expect a high in the mid 50s with thundershowers at times, especially in a possible PSCZ (convergence zone) between Seattle and Everett. Wednesday will feature a more traditional Seattle storm, one that is stronger but more stable. Thursday will feature residual showers. Highs those days will be in the upper 50s.
This weekend looks splendid. Highs in the upper 60s with brilliant sunshine. Definitely a good time to get outside. Have a great day people!
April 30, 2009
6:29 P.M.
My internet has been very strange lately, and many people can confirm the fact that my typing has been really weird. It is fine in Microsoft Word though, so that is where I am typing it right now.
But today, to mix things up, I thought I’d do a Swine Flu forecast since it’s all the rage.
Madrona K-8, Aki Kurose, and Stevens are all closed for one whole week due to possible swine flu infection. What’s next is the question.
A good analogy for this situation is “the pig is out of the sty.” I mean this in the sense that there is no longer a question of swine flu becoming a pandemic. We can take precautions, but swine flu has spread all over the world in less than a week, which gives it enough credentials in my opinion to be called a pandemic. And although the flu has only affected a handful of people, it is doing so at a very quick rate. The thing that makes flu pandemics so deadly and destructive is not necessarily that the virus is more powerful than other viruses, but it is that we have not been exposed to this type of flu and therefore do not know how to combat it. Seasonal influenza consists of similar strains, but H1N1 Swine Flu came from pigs. Needless to say, pigs and humans are very different creatures, and diseases that affect them are different. This pig flu mutated with a human strain however, so now you have the worst of both worlds; an unfamiliar influenza strain that has the ability to pass from person to person. This is not just a strain that we can fight off; the infectious rate is prodigiously high, which explains the rapid pace at which this flu has spread.
I do expect many schools in Seattle to be closed in the next week or so as cases erupt across the county and state. Garfield is a prime location for swine flu to spread since it is a large school that brings people all across the city together. Many of the events coming up, such as the Spring Waltz, will only serve to worsen the situation. Unfortunately, we have already passed the pivotal point of quarantine, but that does not change the fact that it is extremely important to wash your hands and keep yourself clean. Unfortunately, the flu can still spread even when people haven’t started showing symptoms yet, so although I’m not recommending everybody completely stay away from each other, it is prudent to possibly use less physical forms of salutation. Schools are a perfect environment for flu to spread, and I feel like it is our duty as students not to just act in the best interest of ourselves but in the best interest of others as well by taking steps to reduce the spread of this extremely virulent disease. Remember, the Spanish Flu started with one person as well. It ended up killing 100 million. Let’s not let this happen again by keeping clean and using common sense.
April 20, 2009
9:09
Happy 420 everyone! Though I am not someone who practices that holiday. Expect a real update tomorrow.
April 19, 2009
5:30
Again, nothing new to report. And my keyboard is screwing up... arrrghggh
April 18,2009
10:38
What' new? Nothing.
Peace
Charles
April 17, 2009
4:02 P.M.
Never mind.
Remember how I said winter may finally be vanquished? Well for three days in a row the weather models have insisted on a rainy period lasting Wednesday of next week to Friday. Highs then should be in the mid 50s with periods of showers, interlaced with some sunbreaks. In the meanwhile, expect dry conditions with highs in the low 60s tomorrow. Sunday should be absolutely beautiful, and I would not be surprised at all to see the thermometer hit 70 in places. Monday looks even nicer, with highs in the low 70s. Tuesday, clouds filter back in as we get cooler air off the Pacific, and, as I previously stated, expect a chance of rain by Wednesday. Get out and see those cherry blossoms while you can!
April 15, 2009
7:19 A.M.
According to Scott Sistek of KOMO4, winter has finally been vanquished. We are at that time of year when it only gets warmer and warmer, and apart from a few showers Friday, the extended looks warm and sunny. Highs in the mid 60s from the weekend forward!
April 14, 2009
6:14 P.M.
Nothing new to report. Pretty day though, isn't it?
Go Mariners.
April 13, 2009
8:17 P.M.
Man, I've updated this thing twice already only to accidentally click on a link and have to start all over again. Oh well. Third time's a charm right?
The weather today was quite intense. You could say that it brought the ruckus. I don't think there were any reports of lightning but there were reports of marble-sized hail in SE King County and everybody who was out there today noticed some heavy rain and wind associated with the convergence zone showers that were stalled over the area.
This wild weather is very common for spring, and it forms when a large area of low pressure in the upper levels drops down from the Gulf of Alaska. What this does more than bring steady rain is usher in a cold, unstable air mass. In fact, the air aloft right now is just past its peak as far as warmth is concerned. The sun angle is also relatively high for us right now. The sun only serves to magnify the instability of the atmosphere by adding more heat (energy and instability) to the equation.
The forecast for the next week looks benign. Expect some rain on Friday, but temperatures should warm up each day until they settle into the mid 60s next week.
April 10, 2009
7:40 P.M.
I'm trying to get into the habit of updating this thing every day even if I don't really have anything new to say, just to let you know that I'm still alive and doing these forecasts. Not much has changed in my thinking on the forecast... spring is often a time where the best tool for forecasting is your eyes because the weather is often very localized and changes quickly. Forecasts show a threat of thunderstorms Monday as the high April sun shines down on cold air in the upper levels of the atmosphere, inciting instability. Don't be surprised if you get caught in some heavy showers Monday afternoon.
Charlie
April 9, 2009
9:56 P.M.
Not too much new to talk about today... people on the citizen science field trip should have fine weather... there could be a few showers here and there but nothing too serious. Our next significant rain looks to be Sunday, then cold with thundershowers Monday and Tuesday, then drying out Wednesday. There could possibly be more steady rains by the end of next week, and then a dry period.
Feel free to invite your friends to this group because I love it when I can reach out to even more people with this group and teach more people about what I know.
Charlie
April 8, 2009
7:36 P.M.
I'm back from Hawaii now, so I can resume these forecasts. And thanks to those all asking about how Hawaii went; it was a fun experience and I made a lot of new friends in addition to going to some great places.
The weather in Hawaii was pretty predictable. Northeasterly trade winds slam into the eastern side of the island, and as the air gets uplifted over the mountains, it condenses, creating clouds and rain. On the western side, the air dries and warms as it descends down the mountains, resulting in much drier conditions. The different levels of precipitation are quite amazing; it ranges from 10 inches or less on the high desert of haleakala to over 400 inches in the wettest places of the rainforest. Over the adjacent ocean, rainfall averages 25-30 inches per year.
Anyways, the weather here looks like it will be average for spring, with high temps in the low to mid 50s and lows in the upper 30s to mid 40s. A more organized system can be expected Easter Sunday, although it looks like the rain will hold off till the afternoon for the time being, meaning it shouldn't interfere with your morning egg-hunting plans.
Long range forecasts show warm weather next weekend, but that is an awful long ways off. At least it is something to look forward to!
-Charlie
March 20, 2009
12:08 P.M.
Right now, we are seeing a slow moving, weak weather system over the area that is producing showers and snow at higher elevations. Unfortunately, the snow level is above the passes, and rain is falling. UPDATE: 3:14: A strong squall is coming through right now, bringing heavy rain and strong winds. The atmosphere is unstable and fast and I would not be surprised if we see a couple more of these intense showers before the day is through.
March 17, 2009
St. Patty's Day Special
5:49 P.M.
It's been pretty cold for this time of year the past week or so, with everything from showers to downright windstorms in the past 7 days. Sunday featured the strongest storm of the past couple months as a sub 980 millibar low stormed into Central Vancouver Island. We lost power for 12 hours or so, pretty much all day. Some people saw tons of snow to begin the day Sunday, but I didn't see a flake. My house is at a low elevation (+- 80 feet) and we rarely see snow compared to some other parts of Seattle.
There has been tons of snow in the mountains, with Alpental getting over 30 inches in the past two days. Expect this to continue for a while. On Wednesday and Thursday, a cold front will stall off NW Washington and slowly drift southward. Snow levels will be somewhat higher than they have been; about 4000 feet, but that is above most ski resorts with the exception of Snoqualmie Pass.
After that another cold, upper level troft will fill in behind the low, and although most of the moisture will go into Oregon, Washington will remain cool and showery, and the mountains will continue to see snow.
March 8, 2009
9:53 P.M.
I am sooooo tired
As for writing weather forecasts... I'm sorry about completely forgetting about it... I've actually had like NO free time the last month... like actually actually.
But I'm actually gonna write a weather forecast because there actually is a good chance of snow over the next couple days.
Tonight we are looking at cold (below freezing) with a few showers here and there, but nothing huge, and no real accumulations to speak of.
Tommorrow morning and afternoon is what we need to watch for. A convergence zone will set up around shoreling and slowly drift southward through the afternoon hours. Precipitation in this zone will be in the form of graupel, or snow pellets, and snow.
School on Tuesday? I'm guessing a two-hour late start, but it really depends on the roads (obviously). Monday night will be COLD and all moisture will freeze to the roads. Keep your fingers crossed!
And next time I don't write a forecast for a long time throw a shout out to me telling me to get on the ball. It's awesome to write these forecasts when the weather is really exciting, but I think I was spoiled by our huge snow event last December and now everything seems a lot less exciting.
One place we can be certain of snow is the mountains. They will probably pick up another 6-10 inches tomorrow.
Peaces people
February 9, 2009
5:09 P.M.
I'm sorry I haven't written a forecast lately. I've been busy with lots of stuff. But, duty calls! A forecast I shall write. :)
So, what the hell happened last night?
It is believed that the notorious Puget Sound Convergence Zone was responsible for the atrocities committed to my overinflated ego. I didn't think it was possible. The model soundings... they all pointed to something different! But... what can you do? The pesky ole PSCZ got the best of me.
I was expecting some accumulation on the highest hilltops, mainly like Issaquah and places on the Eastside. The convergence zone was stronger than expected and brought some snow to the area. Not too much to really worry about, though. My house got 1/10 of an inch (since we are so close to the lake). Other places got an inch or two.
So, what's up for tonight?
I can say with a lot of confidence that we will see no snow. Here's why.
1.) Temperatures will be below freezing, but only barely.
2.) The storm will hit Seattle later in the day when we have already warmed up.
3.) The biggest factor is that an easterly downslope wind off the Cascades will help to dry the air and migitate snowfall.
The same wind that will prevent snowfall for us will enhance snowfall for the Hood Canal region as this easterly flow rises and condenses over the Olympics, creating lift, condensation, clouds, and snowfall. The Hood Canal area could see up to a foot of snowfall. I would be surprised if Seattle saw 1/4 of an inch.
Just goes to show how our complex terrain makes forecasting difficult.
But that is what makes it fun as well.
Max Elvis David, make some omelets for breakfast tomorrow. You won't need those eggs.
9:18 PM
For some reason, the atmosphere failed to really destabilize, and the expected thundershowers failed to flare up. Tomorrow, in the plains, there will be a huge outbreak of severe weather. I suggest you read about it in the blogs on accuweather.com.
May 11, 2009
6:38 PM
Just like the passage of a contrail disintegrating into the atmosphere due to low relative humidity 37,000 feet up, the AP Euro exam has passed out of us sophomores lives. An anti-climatic climax it was, at least for me, as I could have done more useful things with my time then creating a 45-page outline of the entire year which I didn’t even use. Still, it is a testament to the prowess and power man possesses, which is still reminiscent of the Italian renaissance, especially in individualists such as Pico della Mirandola (Oration on the Dignity of Man).
But now I seriously need to get that stuff out of my life, and get back to weather. That is what this page is about. But still, weather has become a part of me so much that it’s almost difficult to distinguish what it is and what it isn’t. That’s why I ramble on things most people would find totally unrelated to weather. I see the resemblance, and I never erase any of my work. I just type as things come to me. And if you don’t like my approach, you can always look elsewhere. Q13 Fox! Oh joy! The pinnacle of forecasting, the very essence of the art. Yeah right. Q13’s weather is like the kid trying to nudge his head into a circle of kids having a conversation, with only his head being visible between the frames of others. Anyways……… yeah. Ok. Back to weather
I’m mainly looking forward to tomorrow. A cold area of low pressure is spinning due west off of our coast right now, and it is expected to track inland tomorrow. It is currently very weak, but what it will do is offer the cold air needed to spark off instability in the atmosphere. With the sun at a very high angle, the development of showers and thunderstorms will be rapid and swift. Expect a high in the mid 50s with thundershowers at times, especially in a possible PSCZ (convergence zone) between Seattle and Everett. Wednesday will feature a more traditional Seattle storm, one that is stronger but more stable. Thursday will feature residual showers. Highs those days will be in the upper 50s.
This weekend looks splendid. Highs in the upper 60s with brilliant sunshine. Definitely a good time to get outside. Have a great day people!
April 30, 2009
6:29 P.M.
My internet has been very strange lately, and many people can confirm the fact that my typing has been really weird. It is fine in Microsoft Word though, so that is where I am typing it right now.
But today, to mix things up, I thought I’d do a Swine Flu forecast since it’s all the rage.
Madrona K-8, Aki Kurose, and Stevens are all closed for one whole week due to possible swine flu infection. What’s next is the question.
A good analogy for this situation is “the pig is out of the sty.” I mean this in the sense that there is no longer a question of swine flu becoming a pandemic. We can take precautions, but swine flu has spread all over the world in less than a week, which gives it enough credentials in my opinion to be called a pandemic. And although the flu has only affected a handful of people, it is doing so at a very quick rate. The thing that makes flu pandemics so deadly and destructive is not necessarily that the virus is more powerful than other viruses, but it is that we have not been exposed to this type of flu and therefore do not know how to combat it. Seasonal influenza consists of similar strains, but H1N1 Swine Flu came from pigs. Needless to say, pigs and humans are very different creatures, and diseases that affect them are different. This pig flu mutated with a human strain however, so now you have the worst of both worlds; an unfamiliar influenza strain that has the ability to pass from person to person. This is not just a strain that we can fight off; the infectious rate is prodigiously high, which explains the rapid pace at which this flu has spread.
I do expect many schools in Seattle to be closed in the next week or so as cases erupt across the county and state. Garfield is a prime location for swine flu to spread since it is a large school that brings people all across the city together. Many of the events coming up, such as the Spring Waltz, will only serve to worsen the situation. Unfortunately, we have already passed the pivotal point of quarantine, but that does not change the fact that it is extremely important to wash your hands and keep yourself clean. Unfortunately, the flu can still spread even when people haven’t started showing symptoms yet, so although I’m not recommending everybody completely stay away from each other, it is prudent to possibly use less physical forms of salutation. Schools are a perfect environment for flu to spread, and I feel like it is our duty as students not to just act in the best interest of ourselves but in the best interest of others as well by taking steps to reduce the spread of this extremely virulent disease. Remember, the Spanish Flu started with one person as well. It ended up killing 100 million. Let’s not let this happen again by keeping clean and using common sense.
April 20, 2009
9:09
Happy 420 everyone! Though I am not someone who practices that holiday. Expect a real update tomorrow.
April 19, 2009
5:30
Again, nothing new to report. And my keyboard is screwing up... arrrghggh
April 18,2009
10:38
What' new? Nothing.
Peace
Charles
April 17, 2009
4:02 P.M.
Never mind.
Remember how I said winter may finally be vanquished? Well for three days in a row the weather models have insisted on a rainy period lasting Wednesday of next week to Friday. Highs then should be in the mid 50s with periods of showers, interlaced with some sunbreaks. In the meanwhile, expect dry conditions with highs in the low 60s tomorrow. Sunday should be absolutely beautiful, and I would not be surprised at all to see the thermometer hit 70 in places. Monday looks even nicer, with highs in the low 70s. Tuesday, clouds filter back in as we get cooler air off the Pacific, and, as I previously stated, expect a chance of rain by Wednesday. Get out and see those cherry blossoms while you can!
April 15, 2009
7:19 A.M.
According to Scott Sistek of KOMO4, winter has finally been vanquished. We are at that time of year when it only gets warmer and warmer, and apart from a few showers Friday, the extended looks warm and sunny. Highs in the mid 60s from the weekend forward!
April 14, 2009
6:14 P.M.
Nothing new to report. Pretty day though, isn't it?
Go Mariners.
April 13, 2009
8:17 P.M.
Man, I've updated this thing twice already only to accidentally click on a link and have to start all over again. Oh well. Third time's a charm right?
The weather today was quite intense. You could say that it brought the ruckus. I don't think there were any reports of lightning but there were reports of marble-sized hail in SE King County and everybody who was out there today noticed some heavy rain and wind associated with the convergence zone showers that were stalled over the area.
This wild weather is very common for spring, and it forms when a large area of low pressure in the upper levels drops down from the Gulf of Alaska. What this does more than bring steady rain is usher in a cold, unstable air mass. In fact, the air aloft right now is just past its peak as far as warmth is concerned. The sun angle is also relatively high for us right now. The sun only serves to magnify the instability of the atmosphere by adding more heat (energy and instability) to the equation.
The forecast for the next week looks benign. Expect some rain on Friday, but temperatures should warm up each day until they settle into the mid 60s next week.
April 10, 2009
7:40 P.M.
I'm trying to get into the habit of updating this thing every day even if I don't really have anything new to say, just to let you know that I'm still alive and doing these forecasts. Not much has changed in my thinking on the forecast... spring is often a time where the best tool for forecasting is your eyes because the weather is often very localized and changes quickly. Forecasts show a threat of thunderstorms Monday as the high April sun shines down on cold air in the upper levels of the atmosphere, inciting instability. Don't be surprised if you get caught in some heavy showers Monday afternoon.
Charlie
April 9, 2009
9:56 P.M.
Not too much new to talk about today... people on the citizen science field trip should have fine weather... there could be a few showers here and there but nothing too serious. Our next significant rain looks to be Sunday, then cold with thundershowers Monday and Tuesday, then drying out Wednesday. There could possibly be more steady rains by the end of next week, and then a dry period.
Feel free to invite your friends to this group because I love it when I can reach out to even more people with this group and teach more people about what I know.
Charlie
April 8, 2009
7:36 P.M.
I'm back from Hawaii now, so I can resume these forecasts. And thanks to those all asking about how Hawaii went; it was a fun experience and I made a lot of new friends in addition to going to some great places.
The weather in Hawaii was pretty predictable. Northeasterly trade winds slam into the eastern side of the island, and as the air gets uplifted over the mountains, it condenses, creating clouds and rain. On the western side, the air dries and warms as it descends down the mountains, resulting in much drier conditions. The different levels of precipitation are quite amazing; it ranges from 10 inches or less on the high desert of haleakala to over 400 inches in the wettest places of the rainforest. Over the adjacent ocean, rainfall averages 25-30 inches per year.
Anyways, the weather here looks like it will be average for spring, with high temps in the low to mid 50s and lows in the upper 30s to mid 40s. A more organized system can be expected Easter Sunday, although it looks like the rain will hold off till the afternoon for the time being, meaning it shouldn't interfere with your morning egg-hunting plans.
Long range forecasts show warm weather next weekend, but that is an awful long ways off. At least it is something to look forward to!
-Charlie
March 20, 2009
12:08 P.M.
Right now, we are seeing a slow moving, weak weather system over the area that is producing showers and snow at higher elevations. Unfortunately, the snow level is above the passes, and rain is falling. UPDATE: 3:14: A strong squall is coming through right now, bringing heavy rain and strong winds. The atmosphere is unstable and fast and I would not be surprised if we see a couple more of these intense showers before the day is through.
March 17, 2009
St. Patty's Day Special
5:49 P.M.
It's been pretty cold for this time of year the past week or so, with everything from showers to downright windstorms in the past 7 days. Sunday featured the strongest storm of the past couple months as a sub 980 millibar low stormed into Central Vancouver Island. We lost power for 12 hours or so, pretty much all day. Some people saw tons of snow to begin the day Sunday, but I didn't see a flake. My house is at a low elevation (+- 80 feet) and we rarely see snow compared to some other parts of Seattle.
There has been tons of snow in the mountains, with Alpental getting over 30 inches in the past two days. Expect this to continue for a while. On Wednesday and Thursday, a cold front will stall off NW Washington and slowly drift southward. Snow levels will be somewhat higher than they have been; about 4000 feet, but that is above most ski resorts with the exception of Snoqualmie Pass.
After that another cold, upper level troft will fill in behind the low, and although most of the moisture will go into Oregon, Washington will remain cool and showery, and the mountains will continue to see snow.
March 8, 2009
9:53 P.M.
I am sooooo tired
As for writing weather forecasts... I'm sorry about completely forgetting about it... I've actually had like NO free time the last month... like actually actually.
But I'm actually gonna write a weather forecast because there actually is a good chance of snow over the next couple days.
Tonight we are looking at cold (below freezing) with a few showers here and there, but nothing huge, and no real accumulations to speak of.
Tommorrow morning and afternoon is what we need to watch for. A convergence zone will set up around shoreling and slowly drift southward through the afternoon hours. Precipitation in this zone will be in the form of graupel, or snow pellets, and snow.
School on Tuesday? I'm guessing a two-hour late start, but it really depends on the roads (obviously). Monday night will be COLD and all moisture will freeze to the roads. Keep your fingers crossed!
And next time I don't write a forecast for a long time throw a shout out to me telling me to get on the ball. It's awesome to write these forecasts when the weather is really exciting, but I think I was spoiled by our huge snow event last December and now everything seems a lot less exciting.
One place we can be certain of snow is the mountains. They will probably pick up another 6-10 inches tomorrow.
Peaces people
February 9, 2009
5:09 P.M.
I'm sorry I haven't written a forecast lately. I've been busy with lots of stuff. But, duty calls! A forecast I shall write. :)
So, what the hell happened last night?
It is believed that the notorious Puget Sound Convergence Zone was responsible for the atrocities committed to my overinflated ego. I didn't think it was possible. The model soundings... they all pointed to something different! But... what can you do? The pesky ole PSCZ got the best of me.
I was expecting some accumulation on the highest hilltops, mainly like Issaquah and places on the Eastside. The convergence zone was stronger than expected and brought some snow to the area. Not too much to really worry about, though. My house got 1/10 of an inch (since we are so close to the lake). Other places got an inch or two.
So, what's up for tonight?
I can say with a lot of confidence that we will see no snow. Here's why.
1.) Temperatures will be below freezing, but only barely.
2.) The storm will hit Seattle later in the day when we have already warmed up.
3.) The biggest factor is that an easterly downslope wind off the Cascades will help to dry the air and migitate snowfall.
The same wind that will prevent snowfall for us will enhance snowfall for the Hood Canal region as this easterly flow rises and condenses over the Olympics, creating lift, condensation, clouds, and snowfall. The Hood Canal area could see up to a foot of snowfall. I would be surprised if Seattle saw 1/4 of an inch.
Just goes to show how our complex terrain makes forecasting difficult.
But that is what makes it fun as well.
Max Elvis David, make some omelets for breakfast tomorrow. You won't need those eggs.
January 2009
January 25, 2009
3:36 P.M.
There was a little snow this morning and right now, but it isn't really amounting to much. It will continue a little longer and taper off this evening. Again, no accumulations are expected outside of a half inch on grassy areas on the highest hills.
Of greater interest to most of you is probably a fringe snow event on Tuesday morning. Models show a POSSIBLE lowland snow event Tuesday morning before switching to rain in the afternoon.
This is an extremely hard forecast... because temperatures will be right on the fringe. If it holds off at all, there will be no snow.
The precipitation would arrive in Seattle at around 6:00 A.M. This makes it even harder for me to predict if school will be closed.
In short, even if I do a pretty good job on this forecast, there will probably be errors. And I will probably get people repeatedly tell me I was wrong even if I was mostly right.
The rule of thumb to the public's perception of forecasting to the weatherman is: "When we are right, no one remembers. When we are wrong, no one forgets."
I'll keep details streaming in as they come. However, just telling you in advance... fringe snow events in Seattle are some of the hardest events to forecast in the world. We'll see what happens!
January 24, 2009
9:02 A.M.
Ok. My little break is over. Finals were this week, and finals take priority over writing weather forecasts. Let's talk about what happened over the past week though.
In short, there was a HUGE ridge of high pressure creating very warm air aloft. This warm air aloft was very very stable, and it created an inversion. The cold, dense air hugged the ground, and the warmer, lighter air rose above it. This is called an inversion.
An inversion creates very little mixing because the air is very stable, and there is nothing to move it. That is why we had deteriorating air quality and fog in the Puget Sound area. Places with higher elevation, like Snoqualmie Pass, were actually warmer than Seattle many days because while Seattle was in the fog and cool air, Snoqualmie Pass was above the fog and in the warm sector of the inversion. That pattern stayed in place for a while, but it looks as though it is finally beginning to break down.
We will have a weak arctic air mass (nowhere near as strong as the one we saw in December) filter down into Western Washington. The air temperatures in the Seattle area actually will not be noticably different thanks to all fog preventing temperatures from getting too high over the past couple weeks, but the air temperatures aloft will get significantly colder.
We could have a couple fringe brushes with snow on Saturday night and Sunday morning, and maybe again Tuesday night, but this looks unlikely right now, and if it occurred, it would only be a couple inches or so. I'll keep you posted.
The extended looks very active and very wet, with lots of snow in the mountains. Which, I have concurred, is something we need after doing ski bus Friday.
January 14, 2009
9:27 P.M.
I've taken a little hiatus lately because there hasn't really been much to talk about. We are under the influence of a HUGE ridge of high pressure that is bringing extremely warm air aloft and stagnant conditions down below.
High pressure is generally associated with sunshine. Why, you may ask, was it so cloudy today?
The answer is air stagnation and a very strong inversion. The the pressure is so high, and the air is so stable that very little mixing occurs. This leads to moisture being trapped in the lower levels of the atmosphere, and allows for fog and low stratus clouds to form.
What is an inversion, you may wonder? The answer is rather simple. An inversion is when there is air aloft that is warmer than air at the surface and it "caps" the surface air. This prevents mixing of the air masses and is often associated with fog, stratus clouds, and smog. We get our worst air quality when we have inversions.
The inversion we have is extremely strong. I checked the temperatures for the top of Alpental and the base of Summit West this morning, and the differences were astronomical. Summit West was in the mid-20s, and the top of Alpental was in the mid-50s! That is a HUGE difference in temperature with height. It is certainly possible that the temperature at the summit of Mt. Rainier (14,410 feet) could get a higher high temperature than Olympia, one place that usually gets thick fog and has gotten very thick fog lately. That isn't likely, but possible.
Forecasting high temperatures for places in the lowlands is really hard right now because the temperatures could vary as much as 20 degrees based on if you are in the fog or not.
I'll be safe and predict a high of 46 for Seattle tomorrow. We'll see what happens.
Long range models have been erratic but occasionally show possible arctic outbreaks a long ways out. It is WAY to early to make any predictions, but just letting you know.
January 10, 2008
4:35 P.M.
It's been an awesome time for me with all this craziness, but now the fun must cease. We have one more system coming through. Then, models show...
Dryness.
:(
The extended model (GFS Superensemble) shows dryness 16 days out.
Peace yo
This sucks
Anyways, ya'll can look forward to sunny days with highs in the mid 50s.
January 9, 2008
5:56 P.M.
I hate weather. It is the most boring thing in the world.
Okay... well I don't hate it... but I strongly dislike boring weather. It gives me nothing to do but work on other stuff (like AP Euro).
The highlight of this week is some rain Saturday afternoon and night. Otherwise, you can look forward to temperatures in the mid 50s and sunny skies for the next week. Long range models show rain back in the picture 10 days out... I don't know if what I'm gonna do with my spare time until then.
Hope you like boring weather more than I do...
ciao for now
January 8, 2009
5:23 P.M.
You know what I really hate? Boring weather.
That's what we got now. My couple days of bliss are now over. Looking at the forecast models is too hard. The forecast is for painfully boring weather. >:(
Of course, everybody else is probably like "woohoo!"
Those looking for a break in the action will get what they want. Me? zzzzzzzzz...
Let's do a quick review of this storm. Needless to say, it was extremely wet. The first wave of moisture came through Tuesday morning. There was a quick break in the action, and then heavier rain arrived Tuesday afternoon. However, in the Seattle area, a rain shadow prevented rain from getting really heavy. Meanwhile, rain was falling at the rate of an inch per hour in spots.
And it didn't stop.
Wednesday evening, the upper-level flow became more southerly and the rain shadow shifted north as a result. Now, Seattle got a taste of what others had gotten for the last 36 hours.
On the rain shadow, I checked some rain totals around the Puget Sound lowlands, and it is amazing how drastic the differences in precipitation are from place to place. Places like Shoreline got a couple hundreths of an inch of rain up until Wednesday afternoon. Places like Tacoma, meanwhile, had around 4. That's a serious rainfall gradient. Just goes to show how complex weather forecasting in the Pacific Northwest is. You think people in Alabama have to worry about rain shadows?
The rain continued falling until early Thursday morning, ending at around 2 A.M. in the Seattle area.
But the damage was done.
Of particular note was the mudslide/avalanche at Hyak. I never thought that would ever happen. Hyak (Summit East at Snoqualmie) is not steep at all. It's also avalanche patrolled. I NEVER thought in my wildest dreams that an avalanche would happen there, let alone one as huge and destructive as that one.
As some rivers are still on the rise, flooding records are not complete. My cousins however, who live in Snoqualmie, said this flood was higher than any one they had ever seen. They've been through some unbelievable floods too (1990, 1996, 2006, just to name a few). The Snoqualmie crested higher than ever at Carnation, over 61 feet!
As I said before, this flooding situation was actually fairly different than the December 2007 floods. Those had very very very strong wind and had much worse impacts on the coast. A situation that closely parallels this were the November 2006 floods. Expect an in-depth analysis of this storm over the summer. In retrospect, the things that made this storm so destructive, especially for the Cascades, were the duration of time we got the heavy rain, the significant low-elevation snowmelt, the high freezing levels, the heaviness of the rain itself. The thing that really sets this storm apart though were the mid level (5,000 feet) winds. They weren't historically strong (unlike the December 2007 winds), but they were almost due west for most of the event. That's why the Seattle area got rain shadowed. However, these winds SLAMMED into the Cascades as the Cascades were perpendicular to the flow. This allowed for maximum oragraphic precipitation too occur. Again, I'll create a more extensive page on this sometime in the future, but the upper level winds put the word "historic" in this storm.
January 7, 2009
10:41 P.M.
What's golden people? I'll tell you what's golden. The Snoqualmie River will crest higher than it's ever crested before. And who called it? Charlie Phillips > lots of numerical and statistical models.
Alright that's nothing to get cocky about. Any person with any sense knew that the hydro models were underdoing their river estimates. This is just cool cause it makes me feel good about myself, which is always a good thing (unless it turns you into a dick :) ).
The heavy rain is still forecast to taper off around 2 A.M. Tomorrow, I will have a quick update on this storm, and perhaps somewhere down the road, I will post a more in-depth page about it. In the weather off-season (ie late spring, summer, early fall) I may not do these forecasts since I will be out of town but I will work on researching individual events (mainly windstorms) but also flood and snow events.
In the meanwhile, my cousins in Snoqualmie say they are getting flooded more than ever. I went to Snoqualmie Falls earlier last fall (2008) when there was major flooding on it. I looked at reports from KING5 and this event looks much more major.
This storm is much more similar to the November 2006 event than the December 2007 event. More on that later, it's getting late.
Remember: go see Snoqualmie Falls at all costs tomorrow. You will thank me sometime down the road. You will.
4:27 P.M.
This is beginning to look like the real deal folks. I just looked at the data for the Alpental ski resort as well, and they have gotten over 5 inches of rain in the last 15 hours. Several rivers are forecast to reach record severity flooding. The Snoqualmie River is expected to crest a couple inches below record stage. However, I think it will crest at record stage. We will have to see.
The rain shadow that has been keeping us dry while other places have been getting feet of rain has shifted to our north and weekend. This rain shadow, by the way, was extraordinarily strong. I thought there would be a little rain, but I thought there would be more than there was. There was no rain in Seattle this morning, while, to our west, east, north, and south, it was dumping. We are now seeing what everybody else has been seeing for the last 24 hours. It's not hard to realize why so many rivers are flooding when you take the rain we are getting now, make it heavier, and prolong it. That's what it's been like in the mountains. Freezing levels are at 7000 feet, so it is pretty much all rain in the mountains. This storm will be historic. KOMO says, "Heavy rains continue to fall across Western Washington as some areas could see flooding that we haven't seen in generations, if at all."
Still, while some rivers may be flooding at record severity, I got a question from Evan Shay about whether this storm is the same strength as the storm on December 1-3, 2007. It is not, and I can say that with confidence. Even though places in this storm may get even more rain, the December storm was shorter in duration as far as heavy rainfall is concerned and dropped more rain in a shorter amount of time. This biggest difference is wind. Wind is generally the best indicator of a storm's strength since the lower the pressure of a storm, the stronger the wind. Moisture doesn't have as direct of a connection to strength.
Bottom line on these two storms: The former was stronger, mainly because of wind, but this one will lead to flooding just like the other one. Because of upper level flow differences, the Olympics were favored more in 2007. Now, the Olympics and Cascades are favored. The Cascades have seen much more rainfall already than they did in 2007.
The steady rain is forecast to end around 2 AM in Seattle. Still, strong orographic flow will keep precipitation going in the mountains, although it will begin to wind down as well. Check out those links I posted in yesterday's post. AND GO TO SNOQUALMIE FALLS. YOU MAY NEVER SEE IT THIS HIGH AGAIN. I'VE GONE THERE IN SITUATIONS MUCH WEAKER THAN THIS AND IT WAS AMAZING. I doubt your parents will answer your pleas if you really want to go, but trust me... this is the highest I think that river will be for a long time.
Oh yeah, and we dry out tomorrow and keep dry for a week or so. Not much to talk about there... especially when the weather is like it is now.
Have fun in the rain!
January 6, 2009
9:48 P.M.
Woohoo!
Want to know what the NWS says on the situation?
THE OVERALL TREND IS NOT LOOKING GOOD WITH SOME VERY HIGH RAINFALL RATES STARTING TO COME IN THE PAST FEW HOURS
Yeah! That's what I'm talking about!
Precipitation rates look even higher. Isolated amounts of 30, yes, 30 inches are possible in spots. Widespread amounts of 10-15 inches are certain. Avalanche danger is extreme. Rain was falling at the rate of an inch per hour north and east of us. Again, the rain here isn't that bad as of now. There has already been over 5 inches in the past several hours in some spots on the Cascades and Olympics. If you live in a floodplain, move valuables to higher ground. AND SEE SNOQUALMIE FALLS IF YOU CAN. I GET THE FEELING THAT THE SNOQUALMIE RIVER COULD CREST AT AN ALL TIME FLOOD STAGE, EVEN THOUGH THE HYDRO MODELS DON'T AGREE. IT ALL DEPENDS ON HOW LONG THIS RAIN LASTS.
Stay dry under the Olympic rain shadow!
4:59 P.M.
Even if it's not raining at your house right now, it is raining very hard elsewhere. The Seattle metropolitan area is getting shadowed by the Olympics right now. Take a look at the radar, and you can clearly see a lot of rain in other parts of Western Washington. http://www.komonews.com/weather/radar
This shadow, however, will shift further north as time goes on. Therefore, Seattle will eventually get all the heavy rain everybody else is getting. The NWS is expecting 4 inches of rain in Seattle. I think we will see totals closer to 2-3 inches in Seattle proper, but places like Sea-Tac, which are currently not affected by the rain shadow, could see total rainfall amounts close to 5 inches. The Cascades and SW Olympics could see 15-20 inches of rainfall. That is a phenomenal amount of rain, and with all that rain comes flooding. I can say confidently that we will see moderate to major flooding on all area rivers, maybe even a few records. I highly encourage everybody to check out Snoqualmie Falls if they have time. It will be dramatic.
In the meanwhile, we have a little wind in the Seattle area. A wind advisory is in effect for most of Western Washington. We could see wind gusts to 45 mph, which is enough to cause some localized and isolated power outages. The main story over the next few days will be the rain and associated flooding. Here is a great website to see the stages of the rivers and their predicted heights.
http://ahps2.wrh.noaa.gov/ahps2/index.php?wfo=sew
Click on the names of places to see the forecast for the river and more specific information on it.
Remember: If you are up for an adventure and your parents are too, head to Snoqualmie Falls. It is forecast to reach major flooding at this point and may go even approach record stage.
And there is no snow for Seattle in the foreseeable future :)
January 5, 2009
5:20 P.M.
So actually, I just looked at the models and all guidance points to a major flood event for Western Washington. Our most dependable model for the region, the 4 km mm5-gfs, shows a constant, heavy rainfall from 1 A.M. Tuesday morning to 10 A.M. Thursday morning. A rain shadow will protect Seattle from excessive rainfall at first as the flow is westerly, but the shadow will shift north as the upper level flow gets more of a southerly component. models now show rainfall totals as high as 20 inches in the Cascades. Many tv stations are calling for urban flooding, but I don't think it will be that bad due to the rain shadow. We could see some urban flooding when the rain shadow moves north closer to Everett. Bottom line: even if it's not raining here, it's raining elsewhere. HARD. I suggest you go to see Snoqualmie Falls if you can get a ride. It is unbelievable when the river is at major flood stage.
4:54 P.M.
See snow totals HERE: http://www.facebook.com/group.php?gid=33875355514&v=app_2373072738#!/topic.php?uid=33875355514&topic=6006
Let's start out with a review of last night's storm. I actually thought I did a great job of forecasting it. The snow switched to rain at around 11 at my house, but switched later at other places (Mr. Stever, my marine biology teacher, said it turned to rain at 3 A.M. in Shoreline).
Just to get a couple things straight, I did NOT say there was a 10/100 chance of snow. I was fairly certain that there was going snow, and predicted a couple inches in my forecast. I was 10% sure that there was going to be a snow DAY, as I thought the rain would turn the snow into slush.
Things I learned from this: Fringe snow forecasting is really hard. I already knew that, but this just reinforced it. With the temperatures the way they were, a quarter of the time you would see snow, half the time you would see a rain/snow mix, and a quarter of the time you would see rain (that's at least what I think). We got more snow than I expected, and I'm afraid there's not really much I can learn from that. It wasn't a forecasting error or anything. It's just the nature of snow around here. You really have to see the snow falling before you can really put down some hard forecasts in these fringe situations, which is often too late.
I will confess, however, that I was fairly certain that we would have a late start. This wasn't a forecasting error though. I tried to predict SPS, who I've learned is very hard to predict. I thought they would delay because of all the slush on the road. I think they got impatient with all the snow days and just wanted kids to go to school. Even if I can predict weather, predicting the inner thoughts of school officials is even harder.
So... I thought I did well in this situation, but not much better than any other guys. This wasn't really a typical forecasting scenario. It was a "look out the window and see what's happening scenario." Anybody could have predicted this if they knew some basic signs to look for.
This week looks WET. We could see some flooding on area rivers, and after that, we could see a perhaps fairly extended (5-7 days) period of dry weather (which everybody loves except me). I'll right more on it later tonight after the UW models come out. They are one of my best resources.
January 4, 2009
6:59 P.M.
So... it's actually kinda snowing! Awesome for some, problemsome for others. I am looking outside right now, and frankly, I did not expect to see this much of snow (I have about a 1/2 inch outside my house right now). Neither did the NWS. They have issued a SNOW ADVISORY until 9 P.M. for all of Western Washington for 1-3 inches of snow. However, I think that it MAY keep snowing beyond that point. Here's why...
1.) snow acts to keep temperatures cool, and the atmosphere has cooled off from the snow.
2.) the precipitation is fairly intense due to some weak low-level convergence over Seattle and especially Bremerton. When precipitation rates are higher, it brings cooler air down to the surface and gives the snow less time to melt
3.) Cause Chris Swanson controls the weather and he says we are going to have a snow day
This is what you call a fringe snow event. Temperatures are RIGHT on the fringe. The temperature at my house is 34 degrees. Thankfully, dew points are low enough and precipitation rates are intense enough that the precipitation is remaining as snow.
All the other forecasters and the models are in agreement that the snow will change to rain at 9-midnight. I'm starting to head for the later part of that range. I've seen some helpful signs that we could see more snow. The snowflakes are getting smaller (which means the snow is drier, although it is still very wet) and snow is sticking. This is a very tough forecast and I'm listening to every single clue I can get to make a decision.
Models operate my pure mathematical equations. There is some weather wisdom you can incorporate into your forecasts in these times. For example, snow helps to keep temperatures steady. Models say rain tomorrow morning at Snoqualmie Pass. I don't think so. The storm coming in isn't all that warm.
Another good indicator more snow is that southerly winds have died down. We have less of a warming wind to eat away the snow and change the precipitation to rain.
Bottom line... this is a very difficult forecast. But I think that it will continue snowing for a couple hours, and then the precipitation will change over to rain. The best resources at this time are just temperatures and observations from other places. I am hoping for a snow day, but that looks unlikely. However, I have bumped my odds from 1 in 100 to 10 in 100. A 2 hour late start seems much more likely.
Feel free to ask me any questions, but just write them on the wall here. I will answer them. All the chat spazzes out my computer. Your best resource at this time is simply doppler radar and your temperature gage.
ONE MORE SNOW DAY!
12:28 P.M.
Looking at the models this morning, it looks as though there is a slight possibility that the Seattle area may see a little bit of light snow. The most advanced model we have (the 4km mm5-gfs) shows 2 inches of snow in the Seattle metropolitan area tonight as moisture from the Pacific comes streaming in over a marginally cool airmass. The latest satellite observations show that the storm may be slowing up, which does not bode well for snow, but still we could see a slushy inch or two. Later tonight, it will all change to rain. I guess there is a slight possibility that we could have a 2 hour late start tomorrow, but that looks unlikeley. The snow will probably melt and probably not really stick to the roads anyway.
Hood Canal could now see as much as 8 inches in isolated spots, the easterly outflow of cold air dams up against the Olympics there. This does two things: it increases precipitation (because of orographic enhancement) and it cools temperatures (because the air there is cooler). Hood Canal also has a bit of elevation in spots, which helps to keep snow there.
The mountains will see snow regardless. 1-3 feet is still on track for totals from this incoming storm.
Of greater interest is the middle of the week. Models show a very wet and mild pattern with very heavy rain in Western Washington. Seattle may get shadowed by the Olympics, but the mountains will see very heavy rain, and very heavy snow above 6-7000 feet. The models show over 60 inches of snow in a 24 hour period in those spots. Unfortunately, it looks like it will rain in the passes. The rivers look like they are going to flood and there could be some avalanche danger. Stay tuned.
January 3, 2009
Happy New Year Everyone!
I hope everybody had a fantastic New Year, and I hope it will be filled with excitement, love, and other goodies. Out with the old and in with the new! Woohoo!
First, before I explain the forecast, I want to go over a concept that isn't particularly advanced but is rather unknown to much of the greater Seattle area. What if I told you that the snow we get isn't always snow?
Everybody knows what snow looks like... it's white, it's fluffy, and it sticks to trees. Still, not all white things that fall from the sky are snow.
Today was a good example of a time when there was white stuff falling from the sky that wasn't really snow. If fell in pellets, and bounced high when it hit the ground. It isn't hail either though. It's graupel!
Graupel are kinda like snow pellets. They lack the hexagonal structure of a snowflake, but they are not hail either. Many people say we are getting hailed on when they see graupel. I don't know why they don't teach this in the schools. It's one of the biggest weather misconceptions I've noticed.
These pellets are not hail because hail is formed of ice, whereas graupel are still snowy and squishy. Hail are also generally clear, and graupel are white.You can have white hail, but you can NEVER have clear graupel.
To find out if it's hail or graupel, just pick up the sphere and squish it. If it's squishy, it's graupel. If it's ice, it's hail.
Hail is formed inside of a cloud when supercooled (liquid below 32 degrees) water droplets attach to each other and ice over. I'm not sure how graupel is produced, but it's not that way.
I've noticed that graupel usually occurs on cool days a really unstable atmosphere, or in a REALLY intense convergence zone. So for now on, when you see these snow pellets, I want your status to be "It's graupeling outside!"
Alright. The forecast looks fairly interesting, especially for midweek. We will get a strong warm front off the Pacific tomorrow and Monday that will provide breezy conditions, some rain, and gobs of snow in the mountains. The lowlands by Hood Canal may even see 2-4 inches of snow when the precipitation starts, as the airmass we have now is marginally cool enough for snow. The Cascades will see 1-3 FEET, which is great news for ski resorts. Still, the avalanche danger will be extremely high, so this is not a good time to be in the backcountry. I-90 may also close for avalanche control.
Tuesday-Thursday is where it gets interesting. A Pinapple Express will move through the area, blasting snow levels up to 7000 feet. This one looks fairly strong, and it will stall over our area, bringing very heavy rain to the mountains and extremely (several feet per day) heavy snow above that level. With rain in the mountains comes the threat of river flooding. Those who live in floodplains should be warned that a moderate to possibly major flood event is possible the middle of next week.
Hey so I just did some more research on graupel... supercooled water droplets actually are involved. Instead of supercooled water droplets sticking to each other and making compact ice, graupel is a coating of ice formed from supercooled water droplets around a snowflake. It is formed in convective atmospheres (ones with a lot of instability... like the ones we get with convergence zones and strong showers). All these graupel falling also produce a lot of static electricity in the air, which explains why I almost got struck my lightning razor clamming on the coast last year (it was graupeling at the time).
3:36 P.M.
There was a little snow this morning and right now, but it isn't really amounting to much. It will continue a little longer and taper off this evening. Again, no accumulations are expected outside of a half inch on grassy areas on the highest hills.
Of greater interest to most of you is probably a fringe snow event on Tuesday morning. Models show a POSSIBLE lowland snow event Tuesday morning before switching to rain in the afternoon.
This is an extremely hard forecast... because temperatures will be right on the fringe. If it holds off at all, there will be no snow.
The precipitation would arrive in Seattle at around 6:00 A.M. This makes it even harder for me to predict if school will be closed.
In short, even if I do a pretty good job on this forecast, there will probably be errors. And I will probably get people repeatedly tell me I was wrong even if I was mostly right.
The rule of thumb to the public's perception of forecasting to the weatherman is: "When we are right, no one remembers. When we are wrong, no one forgets."
I'll keep details streaming in as they come. However, just telling you in advance... fringe snow events in Seattle are some of the hardest events to forecast in the world. We'll see what happens!
January 24, 2009
9:02 A.M.
Ok. My little break is over. Finals were this week, and finals take priority over writing weather forecasts. Let's talk about what happened over the past week though.
In short, there was a HUGE ridge of high pressure creating very warm air aloft. This warm air aloft was very very stable, and it created an inversion. The cold, dense air hugged the ground, and the warmer, lighter air rose above it. This is called an inversion.
An inversion creates very little mixing because the air is very stable, and there is nothing to move it. That is why we had deteriorating air quality and fog in the Puget Sound area. Places with higher elevation, like Snoqualmie Pass, were actually warmer than Seattle many days because while Seattle was in the fog and cool air, Snoqualmie Pass was above the fog and in the warm sector of the inversion. That pattern stayed in place for a while, but it looks as though it is finally beginning to break down.
We will have a weak arctic air mass (nowhere near as strong as the one we saw in December) filter down into Western Washington. The air temperatures in the Seattle area actually will not be noticably different thanks to all fog preventing temperatures from getting too high over the past couple weeks, but the air temperatures aloft will get significantly colder.
We could have a couple fringe brushes with snow on Saturday night and Sunday morning, and maybe again Tuesday night, but this looks unlikely right now, and if it occurred, it would only be a couple inches or so. I'll keep you posted.
The extended looks very active and very wet, with lots of snow in the mountains. Which, I have concurred, is something we need after doing ski bus Friday.
January 14, 2009
9:27 P.M.
I've taken a little hiatus lately because there hasn't really been much to talk about. We are under the influence of a HUGE ridge of high pressure that is bringing extremely warm air aloft and stagnant conditions down below.
High pressure is generally associated with sunshine. Why, you may ask, was it so cloudy today?
The answer is air stagnation and a very strong inversion. The the pressure is so high, and the air is so stable that very little mixing occurs. This leads to moisture being trapped in the lower levels of the atmosphere, and allows for fog and low stratus clouds to form.
What is an inversion, you may wonder? The answer is rather simple. An inversion is when there is air aloft that is warmer than air at the surface and it "caps" the surface air. This prevents mixing of the air masses and is often associated with fog, stratus clouds, and smog. We get our worst air quality when we have inversions.
The inversion we have is extremely strong. I checked the temperatures for the top of Alpental and the base of Summit West this morning, and the differences were astronomical. Summit West was in the mid-20s, and the top of Alpental was in the mid-50s! That is a HUGE difference in temperature with height. It is certainly possible that the temperature at the summit of Mt. Rainier (14,410 feet) could get a higher high temperature than Olympia, one place that usually gets thick fog and has gotten very thick fog lately. That isn't likely, but possible.
Forecasting high temperatures for places in the lowlands is really hard right now because the temperatures could vary as much as 20 degrees based on if you are in the fog or not.
I'll be safe and predict a high of 46 for Seattle tomorrow. We'll see what happens.
Long range models have been erratic but occasionally show possible arctic outbreaks a long ways out. It is WAY to early to make any predictions, but just letting you know.
January 10, 2008
4:35 P.M.
It's been an awesome time for me with all this craziness, but now the fun must cease. We have one more system coming through. Then, models show...
Dryness.
:(
The extended model (GFS Superensemble) shows dryness 16 days out.
Peace yo
This sucks
Anyways, ya'll can look forward to sunny days with highs in the mid 50s.
January 9, 2008
5:56 P.M.
I hate weather. It is the most boring thing in the world.
Okay... well I don't hate it... but I strongly dislike boring weather. It gives me nothing to do but work on other stuff (like AP Euro).
The highlight of this week is some rain Saturday afternoon and night. Otherwise, you can look forward to temperatures in the mid 50s and sunny skies for the next week. Long range models show rain back in the picture 10 days out... I don't know if what I'm gonna do with my spare time until then.
Hope you like boring weather more than I do...
ciao for now
January 8, 2009
5:23 P.M.
You know what I really hate? Boring weather.
That's what we got now. My couple days of bliss are now over. Looking at the forecast models is too hard. The forecast is for painfully boring weather. >:(
Of course, everybody else is probably like "woohoo!"
Those looking for a break in the action will get what they want. Me? zzzzzzzzz...
Let's do a quick review of this storm. Needless to say, it was extremely wet. The first wave of moisture came through Tuesday morning. There was a quick break in the action, and then heavier rain arrived Tuesday afternoon. However, in the Seattle area, a rain shadow prevented rain from getting really heavy. Meanwhile, rain was falling at the rate of an inch per hour in spots.
And it didn't stop.
Wednesday evening, the upper-level flow became more southerly and the rain shadow shifted north as a result. Now, Seattle got a taste of what others had gotten for the last 36 hours.
On the rain shadow, I checked some rain totals around the Puget Sound lowlands, and it is amazing how drastic the differences in precipitation are from place to place. Places like Shoreline got a couple hundreths of an inch of rain up until Wednesday afternoon. Places like Tacoma, meanwhile, had around 4. That's a serious rainfall gradient. Just goes to show how complex weather forecasting in the Pacific Northwest is. You think people in Alabama have to worry about rain shadows?
The rain continued falling until early Thursday morning, ending at around 2 A.M. in the Seattle area.
But the damage was done.
Of particular note was the mudslide/avalanche at Hyak. I never thought that would ever happen. Hyak (Summit East at Snoqualmie) is not steep at all. It's also avalanche patrolled. I NEVER thought in my wildest dreams that an avalanche would happen there, let alone one as huge and destructive as that one.
As some rivers are still on the rise, flooding records are not complete. My cousins however, who live in Snoqualmie, said this flood was higher than any one they had ever seen. They've been through some unbelievable floods too (1990, 1996, 2006, just to name a few). The Snoqualmie crested higher than ever at Carnation, over 61 feet!
As I said before, this flooding situation was actually fairly different than the December 2007 floods. Those had very very very strong wind and had much worse impacts on the coast. A situation that closely parallels this were the November 2006 floods. Expect an in-depth analysis of this storm over the summer. In retrospect, the things that made this storm so destructive, especially for the Cascades, were the duration of time we got the heavy rain, the significant low-elevation snowmelt, the high freezing levels, the heaviness of the rain itself. The thing that really sets this storm apart though were the mid level (5,000 feet) winds. They weren't historically strong (unlike the December 2007 winds), but they were almost due west for most of the event. That's why the Seattle area got rain shadowed. However, these winds SLAMMED into the Cascades as the Cascades were perpendicular to the flow. This allowed for maximum oragraphic precipitation too occur. Again, I'll create a more extensive page on this sometime in the future, but the upper level winds put the word "historic" in this storm.
January 7, 2009
10:41 P.M.
What's golden people? I'll tell you what's golden. The Snoqualmie River will crest higher than it's ever crested before. And who called it? Charlie Phillips > lots of numerical and statistical models.
Alright that's nothing to get cocky about. Any person with any sense knew that the hydro models were underdoing their river estimates. This is just cool cause it makes me feel good about myself, which is always a good thing (unless it turns you into a dick :) ).
The heavy rain is still forecast to taper off around 2 A.M. Tomorrow, I will have a quick update on this storm, and perhaps somewhere down the road, I will post a more in-depth page about it. In the weather off-season (ie late spring, summer, early fall) I may not do these forecasts since I will be out of town but I will work on researching individual events (mainly windstorms) but also flood and snow events.
In the meanwhile, my cousins in Snoqualmie say they are getting flooded more than ever. I went to Snoqualmie Falls earlier last fall (2008) when there was major flooding on it. I looked at reports from KING5 and this event looks much more major.
This storm is much more similar to the November 2006 event than the December 2007 event. More on that later, it's getting late.
Remember: go see Snoqualmie Falls at all costs tomorrow. You will thank me sometime down the road. You will.
4:27 P.M.
This is beginning to look like the real deal folks. I just looked at the data for the Alpental ski resort as well, and they have gotten over 5 inches of rain in the last 15 hours. Several rivers are forecast to reach record severity flooding. The Snoqualmie River is expected to crest a couple inches below record stage. However, I think it will crest at record stage. We will have to see.
The rain shadow that has been keeping us dry while other places have been getting feet of rain has shifted to our north and weekend. This rain shadow, by the way, was extraordinarily strong. I thought there would be a little rain, but I thought there would be more than there was. There was no rain in Seattle this morning, while, to our west, east, north, and south, it was dumping. We are now seeing what everybody else has been seeing for the last 24 hours. It's not hard to realize why so many rivers are flooding when you take the rain we are getting now, make it heavier, and prolong it. That's what it's been like in the mountains. Freezing levels are at 7000 feet, so it is pretty much all rain in the mountains. This storm will be historic. KOMO says, "Heavy rains continue to fall across Western Washington as some areas could see flooding that we haven't seen in generations, if at all."
Still, while some rivers may be flooding at record severity, I got a question from Evan Shay about whether this storm is the same strength as the storm on December 1-3, 2007. It is not, and I can say that with confidence. Even though places in this storm may get even more rain, the December storm was shorter in duration as far as heavy rainfall is concerned and dropped more rain in a shorter amount of time. This biggest difference is wind. Wind is generally the best indicator of a storm's strength since the lower the pressure of a storm, the stronger the wind. Moisture doesn't have as direct of a connection to strength.
Bottom line on these two storms: The former was stronger, mainly because of wind, but this one will lead to flooding just like the other one. Because of upper level flow differences, the Olympics were favored more in 2007. Now, the Olympics and Cascades are favored. The Cascades have seen much more rainfall already than they did in 2007.
The steady rain is forecast to end around 2 AM in Seattle. Still, strong orographic flow will keep precipitation going in the mountains, although it will begin to wind down as well. Check out those links I posted in yesterday's post. AND GO TO SNOQUALMIE FALLS. YOU MAY NEVER SEE IT THIS HIGH AGAIN. I'VE GONE THERE IN SITUATIONS MUCH WEAKER THAN THIS AND IT WAS AMAZING. I doubt your parents will answer your pleas if you really want to go, but trust me... this is the highest I think that river will be for a long time.
Oh yeah, and we dry out tomorrow and keep dry for a week or so. Not much to talk about there... especially when the weather is like it is now.
Have fun in the rain!
January 6, 2009
9:48 P.M.
Woohoo!
Want to know what the NWS says on the situation?
THE OVERALL TREND IS NOT LOOKING GOOD WITH SOME VERY HIGH RAINFALL RATES STARTING TO COME IN THE PAST FEW HOURS
Yeah! That's what I'm talking about!
Precipitation rates look even higher. Isolated amounts of 30, yes, 30 inches are possible in spots. Widespread amounts of 10-15 inches are certain. Avalanche danger is extreme. Rain was falling at the rate of an inch per hour north and east of us. Again, the rain here isn't that bad as of now. There has already been over 5 inches in the past several hours in some spots on the Cascades and Olympics. If you live in a floodplain, move valuables to higher ground. AND SEE SNOQUALMIE FALLS IF YOU CAN. I GET THE FEELING THAT THE SNOQUALMIE RIVER COULD CREST AT AN ALL TIME FLOOD STAGE, EVEN THOUGH THE HYDRO MODELS DON'T AGREE. IT ALL DEPENDS ON HOW LONG THIS RAIN LASTS.
Stay dry under the Olympic rain shadow!
4:59 P.M.
Even if it's not raining at your house right now, it is raining very hard elsewhere. The Seattle metropolitan area is getting shadowed by the Olympics right now. Take a look at the radar, and you can clearly see a lot of rain in other parts of Western Washington. http://www.komonews.com/weather/radar
This shadow, however, will shift further north as time goes on. Therefore, Seattle will eventually get all the heavy rain everybody else is getting. The NWS is expecting 4 inches of rain in Seattle. I think we will see totals closer to 2-3 inches in Seattle proper, but places like Sea-Tac, which are currently not affected by the rain shadow, could see total rainfall amounts close to 5 inches. The Cascades and SW Olympics could see 15-20 inches of rainfall. That is a phenomenal amount of rain, and with all that rain comes flooding. I can say confidently that we will see moderate to major flooding on all area rivers, maybe even a few records. I highly encourage everybody to check out Snoqualmie Falls if they have time. It will be dramatic.
In the meanwhile, we have a little wind in the Seattle area. A wind advisory is in effect for most of Western Washington. We could see wind gusts to 45 mph, which is enough to cause some localized and isolated power outages. The main story over the next few days will be the rain and associated flooding. Here is a great website to see the stages of the rivers and their predicted heights.
http://ahps2.wrh.noaa.gov/ahps2/index.php?wfo=sew
Click on the names of places to see the forecast for the river and more specific information on it.
Remember: If you are up for an adventure and your parents are too, head to Snoqualmie Falls. It is forecast to reach major flooding at this point and may go even approach record stage.
And there is no snow for Seattle in the foreseeable future :)
January 5, 2009
5:20 P.M.
So actually, I just looked at the models and all guidance points to a major flood event for Western Washington. Our most dependable model for the region, the 4 km mm5-gfs, shows a constant, heavy rainfall from 1 A.M. Tuesday morning to 10 A.M. Thursday morning. A rain shadow will protect Seattle from excessive rainfall at first as the flow is westerly, but the shadow will shift north as the upper level flow gets more of a southerly component. models now show rainfall totals as high as 20 inches in the Cascades. Many tv stations are calling for urban flooding, but I don't think it will be that bad due to the rain shadow. We could see some urban flooding when the rain shadow moves north closer to Everett. Bottom line: even if it's not raining here, it's raining elsewhere. HARD. I suggest you go to see Snoqualmie Falls if you can get a ride. It is unbelievable when the river is at major flood stage.
4:54 P.M.
See snow totals HERE: http://www.facebook.com/group.php?gid=33875355514&v=app_2373072738#!/topic.php?uid=33875355514&topic=6006
Let's start out with a review of last night's storm. I actually thought I did a great job of forecasting it. The snow switched to rain at around 11 at my house, but switched later at other places (Mr. Stever, my marine biology teacher, said it turned to rain at 3 A.M. in Shoreline).
Just to get a couple things straight, I did NOT say there was a 10/100 chance of snow. I was fairly certain that there was going snow, and predicted a couple inches in my forecast. I was 10% sure that there was going to be a snow DAY, as I thought the rain would turn the snow into slush.
Things I learned from this: Fringe snow forecasting is really hard. I already knew that, but this just reinforced it. With the temperatures the way they were, a quarter of the time you would see snow, half the time you would see a rain/snow mix, and a quarter of the time you would see rain (that's at least what I think). We got more snow than I expected, and I'm afraid there's not really much I can learn from that. It wasn't a forecasting error or anything. It's just the nature of snow around here. You really have to see the snow falling before you can really put down some hard forecasts in these fringe situations, which is often too late.
I will confess, however, that I was fairly certain that we would have a late start. This wasn't a forecasting error though. I tried to predict SPS, who I've learned is very hard to predict. I thought they would delay because of all the slush on the road. I think they got impatient with all the snow days and just wanted kids to go to school. Even if I can predict weather, predicting the inner thoughts of school officials is even harder.
So... I thought I did well in this situation, but not much better than any other guys. This wasn't really a typical forecasting scenario. It was a "look out the window and see what's happening scenario." Anybody could have predicted this if they knew some basic signs to look for.
This week looks WET. We could see some flooding on area rivers, and after that, we could see a perhaps fairly extended (5-7 days) period of dry weather (which everybody loves except me). I'll right more on it later tonight after the UW models come out. They are one of my best resources.
January 4, 2009
6:59 P.M.
So... it's actually kinda snowing! Awesome for some, problemsome for others. I am looking outside right now, and frankly, I did not expect to see this much of snow (I have about a 1/2 inch outside my house right now). Neither did the NWS. They have issued a SNOW ADVISORY until 9 P.M. for all of Western Washington for 1-3 inches of snow. However, I think that it MAY keep snowing beyond that point. Here's why...
1.) snow acts to keep temperatures cool, and the atmosphere has cooled off from the snow.
2.) the precipitation is fairly intense due to some weak low-level convergence over Seattle and especially Bremerton. When precipitation rates are higher, it brings cooler air down to the surface and gives the snow less time to melt
3.) Cause Chris Swanson controls the weather and he says we are going to have a snow day
This is what you call a fringe snow event. Temperatures are RIGHT on the fringe. The temperature at my house is 34 degrees. Thankfully, dew points are low enough and precipitation rates are intense enough that the precipitation is remaining as snow.
All the other forecasters and the models are in agreement that the snow will change to rain at 9-midnight. I'm starting to head for the later part of that range. I've seen some helpful signs that we could see more snow. The snowflakes are getting smaller (which means the snow is drier, although it is still very wet) and snow is sticking. This is a very tough forecast and I'm listening to every single clue I can get to make a decision.
Models operate my pure mathematical equations. There is some weather wisdom you can incorporate into your forecasts in these times. For example, snow helps to keep temperatures steady. Models say rain tomorrow morning at Snoqualmie Pass. I don't think so. The storm coming in isn't all that warm.
Another good indicator more snow is that southerly winds have died down. We have less of a warming wind to eat away the snow and change the precipitation to rain.
Bottom line... this is a very difficult forecast. But I think that it will continue snowing for a couple hours, and then the precipitation will change over to rain. The best resources at this time are just temperatures and observations from other places. I am hoping for a snow day, but that looks unlikely. However, I have bumped my odds from 1 in 100 to 10 in 100. A 2 hour late start seems much more likely.
Feel free to ask me any questions, but just write them on the wall here. I will answer them. All the chat spazzes out my computer. Your best resource at this time is simply doppler radar and your temperature gage.
ONE MORE SNOW DAY!
12:28 P.M.
Looking at the models this morning, it looks as though there is a slight possibility that the Seattle area may see a little bit of light snow. The most advanced model we have (the 4km mm5-gfs) shows 2 inches of snow in the Seattle metropolitan area tonight as moisture from the Pacific comes streaming in over a marginally cool airmass. The latest satellite observations show that the storm may be slowing up, which does not bode well for snow, but still we could see a slushy inch or two. Later tonight, it will all change to rain. I guess there is a slight possibility that we could have a 2 hour late start tomorrow, but that looks unlikeley. The snow will probably melt and probably not really stick to the roads anyway.
Hood Canal could now see as much as 8 inches in isolated spots, the easterly outflow of cold air dams up against the Olympics there. This does two things: it increases precipitation (because of orographic enhancement) and it cools temperatures (because the air there is cooler). Hood Canal also has a bit of elevation in spots, which helps to keep snow there.
The mountains will see snow regardless. 1-3 feet is still on track for totals from this incoming storm.
Of greater interest is the middle of the week. Models show a very wet and mild pattern with very heavy rain in Western Washington. Seattle may get shadowed by the Olympics, but the mountains will see very heavy rain, and very heavy snow above 6-7000 feet. The models show over 60 inches of snow in a 24 hour period in those spots. Unfortunately, it looks like it will rain in the passes. The rivers look like they are going to flood and there could be some avalanche danger. Stay tuned.
January 3, 2009
Happy New Year Everyone!
I hope everybody had a fantastic New Year, and I hope it will be filled with excitement, love, and other goodies. Out with the old and in with the new! Woohoo!
First, before I explain the forecast, I want to go over a concept that isn't particularly advanced but is rather unknown to much of the greater Seattle area. What if I told you that the snow we get isn't always snow?
Everybody knows what snow looks like... it's white, it's fluffy, and it sticks to trees. Still, not all white things that fall from the sky are snow.
Today was a good example of a time when there was white stuff falling from the sky that wasn't really snow. If fell in pellets, and bounced high when it hit the ground. It isn't hail either though. It's graupel!
Graupel are kinda like snow pellets. They lack the hexagonal structure of a snowflake, but they are not hail either. Many people say we are getting hailed on when they see graupel. I don't know why they don't teach this in the schools. It's one of the biggest weather misconceptions I've noticed.
These pellets are not hail because hail is formed of ice, whereas graupel are still snowy and squishy. Hail are also generally clear, and graupel are white.You can have white hail, but you can NEVER have clear graupel.
To find out if it's hail or graupel, just pick up the sphere and squish it. If it's squishy, it's graupel. If it's ice, it's hail.
Hail is formed inside of a cloud when supercooled (liquid below 32 degrees) water droplets attach to each other and ice over. I'm not sure how graupel is produced, but it's not that way.
I've noticed that graupel usually occurs on cool days a really unstable atmosphere, or in a REALLY intense convergence zone. So for now on, when you see these snow pellets, I want your status to be "It's graupeling outside!"
Alright. The forecast looks fairly interesting, especially for midweek. We will get a strong warm front off the Pacific tomorrow and Monday that will provide breezy conditions, some rain, and gobs of snow in the mountains. The lowlands by Hood Canal may even see 2-4 inches of snow when the precipitation starts, as the airmass we have now is marginally cool enough for snow. The Cascades will see 1-3 FEET, which is great news for ski resorts. Still, the avalanche danger will be extremely high, so this is not a good time to be in the backcountry. I-90 may also close for avalanche control.
Tuesday-Thursday is where it gets interesting. A Pinapple Express will move through the area, blasting snow levels up to 7000 feet. This one looks fairly strong, and it will stall over our area, bringing very heavy rain to the mountains and extremely (several feet per day) heavy snow above that level. With rain in the mountains comes the threat of river flooding. Those who live in floodplains should be warned that a moderate to possibly major flood event is possible the middle of next week.
Hey so I just did some more research on graupel... supercooled water droplets actually are involved. Instead of supercooled water droplets sticking to each other and making compact ice, graupel is a coating of ice formed from supercooled water droplets around a snowflake. It is formed in convective atmospheres (ones with a lot of instability... like the ones we get with convergence zones and strong showers). All these graupel falling also produce a lot of static electricity in the air, which explains why I almost got struck my lightning razor clamming on the coast last year (it was graupeling at the time).
December 2008 (Lots of snow discussions!)
December 30, 2008
This is a very difficult forecast to make. First of all, tonight and tomorrow, it will be rainy and windy. A winter storm warning is in effect for the mountains for 1-2 feet of snow. A typical winter storm... that's pretty much it.
The forecast for Thursday is SO complex and SO complicated. Usually, as time gets closer, models converge on a situation. Here, they have deverged. One model, the GFS, brought a 963 low into central Vancouver Island two days ago for Thursday. The NAM brought a weak 1000 mb low into SW Washington. That's a huge difference in strength, and a huge difference in track.
Now the models look like they have finally converged on a scenario, although they still are far from lining up. They take the low pretty much right over Seattle at 985 mb. The NAM is still weaker and the GFS is still stronger... but at least there is some agreement now.
All this confusion is because of different zones of low pressure forming around this swath of moisture. The GFS first brought one big low pressure center and the NAM brought three really close together. Now both of them bring two.
While this while relax the wind, it could make for some extremely heavy snow in the mountains. It could even make for some extremely heavy snow in the north interior. The NWS says NOTE THAT ON A
MORE SOUTHERN TRACK WE WOULD ALSO NEED TO KEEP AN EYE OUT FOR THE
POSSIBILITY OF A VERY HEAVY DUMP OF LOWLAND SNOW NORTH OF THE TRACK
OF THE CENTER AS STRONG EASTERLY FLOW IN THE LOW LEVELS GETS OVERRUN
BY TONS OF MOISTURE IN A DEEPENING STORM WITH WET BULB COOLING IN
THE LOWER LEVELS AS HAPPENED ON NOVEMBER 19 1996 AND AS HINTED AT BY
MODEL OUTPUT STATISTICAL SNOW AMOUNT GUIDANCE OFF THE 12Z AND 18Z
GFS.
So if the low tracks further south, we could see some snow!
The whole thing is very confusing though, so stay tuned!
Deceber 25, 2008
I know its been a while since I have posted. I've been extremely busy with last minute shopping and Christmas stuff (not to mention tired out from all the previous weather). But I decided I better keep a regular schedule if I want people to keep reading my blog. Now that the snow for the lowlands is pretty much over, I'll resume to a more regular routine.
Its late and I'm wiped out, but the main story looks to be less snow down here, but a WHOLE lot of mountain snow. Friday/Saturday could have urban flooding as a lot of the snow melts and .5 inches of rain falls on top of it. The mountains meanwhile are going to get hammered. By Tuesday, it is possible that 5 FEET of snow will have fallen in some spots. Alpental opesn tomorrow, and I hope to be the first one on the slopes. Good night!
December 20, 2008
Predicted:
Actual: (too early again)
This is going to be crazy. This storm will be life-threatening.
As of 11:17 AM Saturday morning, the storm is moving faster than expected. New radar shows the leading edge of precipitation slowly making its way to the NW, with the leading edge near Olympia right now. This storm will dwarf the convergence zone we had on Thursday. Although snow totals here should be about the same, there will be NO question in your mind that this storm was clearly the greater of the two.
First, let’s get to some extremely low temperatures that occurred early this morning. This morning was EXTREMELY cold throughout Western Washington, due to the arctic air that was already in place and strong radiational cooling (cooling at night where heat radiates back into space). I never thought I would see this in my lifetime, but some places in Western Washington actually had lows below 0 degrees! Arlington had a reading of -3 this morning! Seattle had a low of 14. All this does for us is to up the chances that all precipitation will be snow. The cold temperatures alongside the faster-moving front confirm that we will see a mainly snow event without much sleet or freezing rain north of about the Tacoma area.
I’m typing this up on Microsoft Word to see if I can post pictures, which I haven’t been able to do on Facebook. Then I will copy this text and put it into the recent news section of my group on Facebook: we will see if the photos work! If they do, you probably will learn a lot more and get a greater in-depth look at what we are expecting as far as snow and wind.
This is a high-confidence scenario. Models have been remarkably consistent with the winds and precipitation, so there should be no questions about who will get the heaviest amounts of snow, how will get medium amounts, and who will get little or even none.
First, let’s break down the weather warnings in Western Washington.
Oops so that picture didn’t even work on Microsoft Word. What we are looking at is a BLIZZARD WARNING for the Olympics, Western Strait of Juan de Fuca, North Coast, West Slopes of the North Cascades and Passes, and West Slopes of the Central Cascades and Passes. This means that heavy snow with sustained winds over 35 mph is occurring or imminent. This is life threatening folks. Do NOT travel in this. You could die. Actually.
A lesser but still significant WINTER STORM WARNING is in place for all of Western Washington and Eastern Washington, apart from the Cascade foothills and Sequim where little or no snow is expected. Amounts here could range from 2 FEET by the Kitsap peninsula to 3 inches near Bellevue.
Why the huge range?
This storm is packing some potentially catastrophic easterly, downslope winds. Depending on where you live, these winds could either act to increase the amount of snow you will receive or decrease it. People living on the Kitsap peninsula will have these winds slam into the Olympics, creating an orographic (topographically induced) effect on snow totals, pushing them up. The foothills will have these same winds, but much stronger. However, they will be traveling DOWN mountains instead of traveling UP them, acting to decrease the snow totals here. Seattle will be between these two areas as far as snowfall is concerned, with anywhere from 3-8 inches likely. Sequim will be shadowed by the Olympics much like Seattle was on Wednesday, so they will see little, if any snow. I laugh at Sequim. :P
However, this storm is no laughing matter. This is SERIOUS. The media hyped up the storm earlier in the week about the same amount as this one. These storms are TOTALLY different. This storm is MUCH, MUCH stronger. Can’t stress that enough. Let’s see if I can post a UW model run of the amount of snow we are expecting.
As you can see, the highest amounts look to be in the mountains and on the Kitsap peninsula, with the lowest amounts by Sequim and the foothills, especially Enumclaw.
Alright, let’s get to wind.
As much as snow is a concern, my biggest concern is wind. Winds could reach HURRICANE force in places near the foothills. Here are some MM5-GFS model runs for the winds. Notice how they get stronger, peaking early Saturday night/early Sunday morning.
As you can see, the winds intensify through the afternoon. This last frame, which shows the winds at 2200 hours local time (10 PM) shows sustained winds of over 50 knots near the foothills, especially those like North Bend and Enumclaw. The winds should remain this strong until about 1 AM, when they will start to die, although still INCREDIBLY strong. I’m going to make an attempt to convince my mom to drive me out there at night so that I can experience and get some video footage of this. My mom is probably going to say no, and for good reason. This is very dangerous. Still, if I do go, you can bet I will be out there reporting with 80 mph gusts behind me and windchills of -25.
Cliff Mass says that the models often overestimate the strength of these winds, and forecasts sustained winds of 34-45 with gusts to 60-70. I’m going a little higher, with sustained winds 40-50 with gusts 70-80, possibly as high as 100 in isolated spots.
These winds will knock out power and cause extreme damage to foothill locations, especially those of MAPLE VALLEY, NORTH BEND, and ENUMCLAW (Enumclaw is generally the windiest foothill).
With the arrival of high winds and cold temperatures comes two other concerns: Frostbite/hypothermia and Carbon Monoxide poisoning. Windchills will approach -25 degrees Fahrenheit and power could be out for weeks. DO NOT PUT A GENERATOR IN YOUR HOUSE TO MAKE HEAT. PUT IT OUTSIDE. Carbon Monoxide is a colorless, odorless gas produced by combustibles. Remember how many deaths occurred in December 2006 because of our windstorm? This event is less widespread and people living in the foothills are more accustomed to these events, but I hope that the message gets out that Carbon Monoxide can kill you and you should NEVER be in an unventilated area with a generator or other combustible appliance.
That’s pretty much all for now. The extended looks cool and we may see some more snow, but not an event as dangerous as this. Long range models even showed some more arctic air masses working their way down through here next week. Hang on to your hats…
On a lighter note, here were some of the temperatures recorded this morning.
Univ of Washington 19
Mountlake Terrace 13
Lake Forest Park 9
Woodinville 8
S Everett 8
S Whidbey Island 8
Marysville 3
Arlington AP -3
Looks like pics didn't show, oh well. Can't have everything in life.
December 19, 2008
Predicted: 27 18
Actual: 27 20
Snow totals from this event can be found here: http://www.facebook.com/group.php?gid=33875355514&v=app_2373072738#!/topic.php?uid=33875355514&topic=5804
I really needed a breather yesterday. That's why I didn't write a forecast. I love this group, but enough is enough (Emmett Akeley knows this for a fact). Of course, the forecast for the next few days is as challenging as the last, maybe even more. We will have a very warm Pacific system overrunning frigid air, and this could have a variety of effects for Seattle.
First, let me give my opinion on the weather events over the past couple of days, including what I did well and what I could have done better.
For Wednesday, the schools should have never canceled. The lack of snow was expected. We were supposed to see an inch at most, probably less. The problem is that the media ALWAYS overhypes snow events. When there is a CHANCE of snow, the media makes it seem like snow is CERTAIN. Of course, meteorologists have to do some things too. And I learned some lessons from that storm.
I should have emphasized the fact that we probably wouldn't see snow more. People were surpirsed that we didn't see snow but I wasn't. I thought I had made that clear. But looking back at my forecast, I realized that I really hadn't. So in the future, I will emphasize the FACTS about snow more, cause the media usually only acts to screw things up (cause that is how they make money, right? By having names like "Storm of the Century" and captivating the audience so they get more viewers). Next time, I will try to make this more clear.
Also, this storm reinforced my belief about convergence zones. You can often predict that they are going to happen, but it is hard to predict WHAT will happen. Wednesday night, while I was forecasting 1-5 inches of snow, Fox was forcasting 1/10. We were both wrong. Totals were more like 3-8 inches. The funny thing is my initial forecast was the most accurate... 3-6 inches. Funny how that works. People paint an intial forecast, then freak out as details change, but if they stayed with the initial forecast, they would have been more correct. I'm not saying that longer range forecasts are more accurate, in fact they never really are because model errors are magnified over the long run. Still, that's how it worked yesterday, even if it was by chance. That's called irony.
Remember how I was saying it wasn't really a convergence zone? That was exactly what happened. Instead of two winds colliding, the warmer southerly wind, since it was less dense than the colder northerly one, lifted over it. This lift created snow showers. This zone stayed over us for quite some time, dropping anywhere from 3-8 inches of snow over the Seattle area. I did a better job then most of forecasting this, but still, the NIGHT before, all models were saying we would get about 2 inches at the most. I got kinda lucky, and although there is definitely some skill, I just chose the right side. In reality, just cause I forecasted this event better than the NWS or tv stations doesn't mean I'm somehow more skilled than them. I most certainly am not. I'm a kid, and they are professionals. Except for Q13 Fox. They just suck in every regard. =D
Looking at the snow totals, it looks like the snow lottery winners in the Seattle area were Beacon Hill, with Amie Szeto from Beacon Hill reporting a little over 8 inches before it was all said and done. Of course, we had an accidental report of 4 feet from Sammy Lesnick, and Jamie Daudon posted a grand total of 60 feet from the Arctic circle, but these reports are questionable at best. Generally, the highes snow totals appeared to be right around Beacon Hill and Mt. Baker. Places further north, like Wallingford and Magnolia, only got 3-4 inches. Since the temperatures were below freezing all day, there wasn't that much of a variation in snow amounts with elevation (for once)
I was up all night of course waiting for snow... I woke up at 3 A.M., too excited to fall asleep again. I looked at the radar and saw a convergence zone (an actual one) forming right over my house. As it got stronger, it got wider, and the snow intensity increased. One common misconception that I have seen is that we received hail. We recieved something similar, but not the same. We received snow pellets, which are extremely common with convergence zones, actually more common than snow itself with narrow, intense ones.
At around 5 A.M., a HUGE lightning flash struck extremely close to my house... probably 40-100 yards away. There was no pause at all between the lightning and thunder, and the flash was nearly blinding. At first, I thought it was a huge power surge. It then began to snow very heavily. Shaken but not stirred, I continued checking the radar and chatting on facebook (which in retrospect was probably not smart at all). A minute later, another lightning flash struck very close to my house. This one was a little further away, but still extremely loud. At that point, I shut off my computer and all electronic appliences. I didn't want a power surge to ruin my computer, and I didn't want to get indirectly struck because I was holding an AC/DC appliance. I walked outside real quick (boy I am full of dumb ideas) to see if I could feel the charge in the air. I could, and my hair started to stand up. I actually think I explain somewhere in the discussion topics another experience with static electricity in which I almost get struck by lightning. It should be under "unusual weather experiences" or something. If it's not or you want to hear more, just write on the wall and I'll tell the story. :)
Alright... so let's get to the forecast... oh man... just remember that if I get this oen wrong, the fact that I got yesterday cancels out any egging opportunity. Sorry Max Elvis David and Christopher Swanson, but you may have to be eating omelets for the next 6 months.
Aight...
So... the forecasting models show three possible major weather events here. First... a major windstorm could be on tap for the foothills of Western Washington. Models have slacked off a little on this one, but some are still adamant (the GFS) in bringing SUSTAINED winds of over 60 mph to some foothill locations (most notably, North Bend) with gusts approaching 100 mph. This would be an extraordinary wind event. Meanwhile, winds in Seattle would be much less, with gusts maybe over 45 mph. I'll talk about timing later, but the winds appear like they will be the worst late Saturday night and early Sunday morning, as the low pressure system approaches from the west and high pressure remains centered in Eastern Washington. This event has some serious potential, and you bet that I will be up in North Bend to capture some footage if we do indeed have the high winds that some models are forecasting.
Next... snow
We could see a much more widespread snow event. Seattle proper could see 1-6 inches of snow, and places like Hood Canal could see as much as 2 feet! Places like West Seattle will see much more snow than places like Bellevue. The further east you go, the lower the amounts will be.
Why, you may ask?
When air flows down, it warms and dries. It should still be very cold (since the air in Eastern Washington is so cold) but it should be VERY dry. This dry air will limit snowfall in those areas. Of course, Seattle is right between the areas where little snow is expected and where a ton is expected. So expect a steep gradient.
These overrunning events are extremely hard to forecast. Be on the lookout for meteorologists pushing back the start times for precipitation. This usually signals that the total snow accumulation will be rather limited. We really don't know how much snow we will get until the storm is actually on top of us and we can see how this storm interacts with the local terrain.
Third, we could see freezing rain...
And I just heard on the radio that Paris Hilton's house got broken and 2 million dollars worth of jewelery got stolen. Tell me why Paris Hilton has 2 million dollars worth of jewelery and people who actually do stuff, even if it's flipping burgers, live in poverty? Oh well...
Sorry. Back to the freezing rain, this will be a classic overrunning event, where warm Pacific air overruns cold, arctic air. What you can get is rain forming because the air aloft is warm, but then freezing as it hits the ground because the ground is still below freezing. Too early to go into depth about that... but it could happen.
These overrunning events are extremely difficult to forecast... but I have confidence that we will at least see some snow before it is all over. I may do an extended forecast later, but I've spent about 45 minutes writing this, and I'm ready for a break. The extended looks cool, but not cold, although we may see some colder air filling in after Sunday, which would again freeze snow to the roads, although not a hard freeze.
Jeez... this is a pretty good workout. I hope I don't throw up... jk
As of 12:34, pretty much all of Western Washington has a winter storm watch, and the eastern lowlands (mountain foothills) have high wind warnings.
December 17, 2008
Predicted:
Actual: (too early)
So... as soon as the new weather models came out last night, I really wanted to write a new forecast. I was really tired though, so I didn't. The new models showed two things: first, they showed an even stronger snow shadow over Seattle. A snow shadow is where air sinks and dries off of a mountain range (in this case the Olympics), leaving little moisture for areas downwind of them). Second, they showed warmer temperatures as the low pressure system moved further north than expected, bringing southerly winds with them. I had that "sinking feeling" that A.) There was going to be school tomorrow B.) I would end up with an egg on my face before the week was through and C.) I was going to have to suddenly do a lot of homework.
Luckily for me, the school districts don't know about the UW atmospheric sciences page! (I highly suggest you check it out, just google it and look at the forecasts)
Really though, I wasn't that off. Snow totals were an inch less than I expected, and I expected an inch.
I can't stress this enough though. DON'T GIVE UP HOPE!!! I EXPECT to see snow tonight, especially in north Seattle. A convergence-zone thing will occur, expect it's not really a classic convergence zone. It is more akin to a deformation band, which is diverging air aloft and converging air at the surface. Main point is... at around 7 P.M. tonight, temperatures will cool back below freezing and snow will begin. The band of snow will be centered in N. King/S. Snohomish counties, but it will slowly drift south.
Convergence zone snow amounts are extremely hard to predict. I actually believe that the worst case scenario would leave a foot in Seattle (best case for me). Anywhere from 1-5 inches looks more likely.
Alright I'm gonna go bench 5 Billion tons of weight right now, but I'll make another update when I'm done. Just wanted to explain what is going on, and that snow is still in the forecast.
Alright, it's 6:04, and I'm back. First, before I talk about the weather, I want to share a very funny story about my weightlifting. I had not had anything to eat this morning, so my blood sugar level was very low. I also had a VERY intense workout. So intense that I threw up. Once I started feeling nausea, I headed to the elevator to get on a floor with a restroom. I started feeling REALLY bad in the elevator. I hopped out on the 8th floor, looking for a restroom, and not having the sense to just look for a trash can (my mind was racing at that point). Suddenly, right in the middle of the sports bar, I threw up. I covered my mouth with my hand, still not thinking about the obvious; a trash can. A lady behind me saw me, had a startled look, and walked away. Suddenly, more volumes of gastric fluid lurched up my esophagus. I couldn't hold it no more. A plethora of (well, I don't want to gross you out... it wasn't too bad). Then, a little asian lady working at the counter got mad at me. She was like, "You throw up? Dummy!" I felt kinda bad and offered to help her, but I think she was worried I would throw up on her and make matters worse. I felt extremely sweaty, not only because I had just thrown up but because everybody was looking at me. At one point, a college kid with a hoodie walked out of the elevator and gave me the most despicable, contemptuous look. It was bad...
But hilarious in retrospect.
What does this have to do with weather, you might ask?
I wouldn't have been at the WAC weight room, and wouldn't of had this great story to tell, if the forecast wasn't so hard!
So what happened?
The problem in Seattle is that even when there is a slight chance of snow, the media hypes it up SO much. If there is a 50 percent chance of snow, they will say it is certain. And when that 50 percent doesn't come, the only ones not surprised are the meteorologists. I'm frankly not surprised at all that we didn't see any snow today. The Olympic snow shadow was in full effect today, blocking out ALL moisture headed towards our area. I thought it would block out most. I was only a little off, but since we are talking about snow, that effect gets magnified. It was also warmer than expected due to the low pressure system tracking more to our north, which brought a warmer southerly wind as opposed to a colder northerly one.
Tonight though, I am much more confident that we will get snow. And here's why...
Now, the Olympics will not act to limit our snowfall. They will help create it! But how, you might ask?
THE PUGET SOUND CONVERGENCE ZONE!!!
This nightmare for forecasters but hero for kids forms when a NW wind hits the Olympics and splits. One part goes into the Strait on Juan de Fuca, and another part goes through the Chehalis Gap. They meet in Western Washington, and when they meet, there is often precipitation (and often snow). The most often place for the PSCZ to meet is right on the Snohomish/King county line. Take a look at the radar right now. You will see a stationary band of snow from about Lake Forest Park north. This is the convergence zone. Over the course of this night, the convergence zone will shift down south, dropping anywhere from 1-5 inches of snow with it. This is a pretty wide range, and it is really hard to predict where the convergence zone will go. We could even get over 5 inches. And, of course, there is always that possibility that we could get none. But all in all, I am MUCH more confident that we will get snow tonight with this convergence zone. The only things that could really mess us up are if the convergence zone stays north and the air mass doesn't cool off as much. All models are in agreement that those things will not happen though.
Here's my time frame:
7-11 P.M. The convergence zone will be in full force, especially over northern king and southern Snohomish counties. Some places to the south will see light snow or mixed snow and rain showers, but these will increase in intensity and snow percentage due to the convergence zone sliding south and temperatures cooling.
11 PM-4 AM: The zone will shift south and stall over the Seattle area, bringing some snow with it.
4 AM-7 AM The zone may shift even further south, towards Sea-Tac or so, before finally fizzing out.
I hope I am right. If I'm not, I am going to be SCREWED tomorrow.
Do a snow dance... for me =)
No extended forecast tonight... do you really care what the weather is going to be like in a couple days? I'll continually update this page as new information comes in.
So the new weather models came in. And they brought some news with them. Drumroll…
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The snow still looks on track! A few details have changed though. The snow looks like it will arrive much later in the evening (well technically tomorrow morning). One model, the GFS, says the snow will arrive in Seattle at 3-4 AM and last for a couple hours, dropping approximately 1-2 inches of snow here. Another model, the NAM, says that the snow will arrive in Seattle at 6 AM and last a little longer with some higher snow totals… anywhere from 1-4 inches. I can’t stress this enough. Don’t freak out that it isn’t snowing now.
In the event that there is school tomorrow, bring eggs. Throw them at me. Or bring something to make fun of me. It would be hilarious. Especially people in band class. That would be AWESOME!!!
However, if I’m right, ya’ll gonna respect my authority. And I still think I’m we are gonna get snow tomorrow.
As for which model to go with, I am going with the NAM. This could complicate matters again because of timing… so again I don’t know what the school district is going to do. In any event… snow will stick to the roads.
Charlie Phillips thinks there will be snow, and Charlie Phillips thinks that there will be a complex decision to make by the school district. If all goes well though, there should be no school on Thursday.
Thank you God.
Updated at 10:17 P.M. Wednesday
I forgot to mention that even if we don't see a convergence zone, we could see a few pop-up showers that could drop some zone. In fact, the radar shows some headed towards us right now, but they also look to be fizzling out.
Talk about high stakes.
Hope to not see most of you tomorrow...
December 16, 2008
Predicted: 31 19
Actual: 31 20 (So close...)
Get ready...
Its been cold, but its been dry as well. There were probably fewer clouds in the sky than fingers on my hand the last two days. But here comes the moisture.
Here's a horrible joke that doesn't make sense at all.
Q: What do you get when you mix moisture and cold temperatures?
A: Snow!
That may be the worst joke I've ever told, and believe me, I've told some pretty bad ones. That wasn't even even a joke actually. That was just a statement of blatant obviousness determined to be a joke by yours truly. Maybe because it just fit into that form so perfectly, or maybe because I just love telling horrible jokes that only make sense literally.
Alright enough with the trigonometry... let's get off these tangents.
Tonight, clouds will be on the increase as a low pressure system drops down from Canada. This is the southern fringe of the system that will give us snow tomorrow.
Alright... enough of this cloud gibberish... let's get down to what matters.
Snow should first start in the northern zones at around 1 A.M., save perhaps a few isolated flurries before that. The snow should work its way into the Puget Sound area by 6 A.M. However, the snow in Seattle should be rather limited at first because of a snow shadowing effect off of the Olympics. So Seattle may get an inch from this storm, maybe more, maybe less. However, later in the day, a convergence-like zone will form north of Seattle, which could bring some snow there, and it will later drift down south through Seattle. As I believe I said yesterday, this could act to balance snow totals out. All in all, the Seattle area will probably see anywhere from 1.5-5.5 inches of snow. However, these amounts could be significantly higher if that convergence zone stalls over Seattle and is stronger than currently expected. Any snow that falls will stick to the roads. The roads are frigid and the temperatures will be at freezing or below. This could complicate the morning commutes for the rest of this week, especially Thursday and Friday.
All you students are probably wondering about school. Frankly, for Wednesday, I have no idea what the district will do. There should be some light snow in Seattle by 6-7 A.M., but not enough for it to really a problem on the roads. And the districts usually make their decisions at 4 in the morning or so, so there wouldn't be any snow on the ground then.
It all comes down to if the district decides to play it safe and foresee the snow situation, or if they take a risk. For that, I can only provide the forecast. The district, as you all know, has a mind of its own.
Thursday will almost certainly be a snow day. Friday should be one too, as the temperatures on Thursday will not climb above freezing. In fact, they will stay in the mid 20s. Even if Thursday is not a snow day, there is a small chance of a snow day Friday as one model showed a weak arctic front dropping down from the north, which would drop a quick inch of snow or so, and then freeze it solid to the roads. Only one model (NAM) showed this though, so the probability of this happening isn't terribly high.
Sunday, the models bring some more snow into the area. It doesn't look like quite as much as before, but it is really to early to pin down any amounts. I will have to wait a day or maybe two before I can begin to make any reasonable estimates.
Also, the extended now looks cool, and not cold. If the models are correct, we should be under the influence of a maritime polar airmass, not a continental one, as the trough in the jet stream that is giving us all this cold weather shifts over to the east. This would be a great pattern for snow to the mountains, with snow levels around 1,000 feet. That's about 1,000 higher than it is right now though.
Stay warm and do some snow dances!
Forecast:
Wednesday: 34 28 snow
Thursday: 31 27 snow showers
Friday: 27 18 mostly sunny
Saturday: 25 17 high clouds
Sunday: 32 25 snow
December 15, 2008
Predicted: 29 20
Actual: 30 20 (what now Jeff Renner)
Today was pretty cold. The coldest we've been in two years (we had a couple of days in 2006 that were about this temperature). It was cold, but it was sunny. There was hardly a cloud in the sky. That's usually the way it works in western washington. When we are cool, we are usually under the influence of a polar maritime airmass (storms coming from the Gulf of Alaska). But for us to get cold, we have to be under the influence of a polar continental airmass. And these airmasses are brought to us by domes of high pressure, because that is what arctic air is. The colder the air, the denser it is, and the denser the air, the higher pressure it is. Arctic highs have the highest high pressure of any high pressure systems. That was pretty bad wording, but basically it means that arctic high pressure systems are stronger than temperate or tropical ones, because the air involved with them is colder, and therefore denser. The higher the pressure, the harder it is for lift to occur, and lift is what creates condensation, and condensation creates clouds and precipitation. There were hardly any clouds in the sky today. This is another reason why it is hard to get snow here... when you finally do get cold temperatures, there's no moisture to be found.
But have no fear... clouds will soon reappear.
A low pressure system of moderate strength will drop down from Canada of Wednesday morning. All precipitation will be snow. Earlier we were thinking of more widespread 3-6 inch amounts, but new model guidance suggests a rain shadow over the Seattle area, which would give us amounts of 1-2 inches, while other places could get as much as 6-7 inches. However, a convergence zone may develop in the wake of this low pressure system, which could bring more snow to Seattle. So all in all, it MIGHT balance out. Convergence zones are very tricky to forecast though, so no guarentees. One thing for sure is that the Seattle metropolitan area will be shadowed from snow by the Olympics. Sorry people. We will still get snow though, and 1-2 inches of snow sticking on the roads is MORE than enough to close the schools.
About school closures... this system is coming in Wednesday morning at right about the time of the morning commute. This will make it tough to forecast if schools will close. Whether or not the close Wednesday, I think they will be closed Thursday and Friday. Even though we don't have a lot of snow, the road temperatures are very cold, and any snow that falls will stick to them.
Thursday=residual showers, much like Sunday.
Friday=REALLY cold... highs will struggle to get into the mid 20s as an even stronger arctic high dives down from Canada.
Saturday and Sunday: this is where things get really interesting. Models are all over the place on this one. The GFS model (American) shows a strong low pressure system coming to our north, which would give an initial period of heavy snow and then possibly change it over to rain. The ECMWF (European) shows a weaker low pressure system coming into our south, so we would have less precipitation, but more of it. Giving forecasts for snow would be like finding the needle in the haystack at this point, but the models suggest a snow event perhaps heavier than the one we will have on Wednesday. Heck, if you took an average of the two models, we could see some REALLY heavy snow.
After that, ANOTHER arctic air mass comes through. And snow falls on Christmas! Then another comes through. And another. The models have only been semi-consistent with this pattern, but still, we could be in the cold for a long time. Ice skating on that pond? How bout ice skating on Greenlake? (well probably not that cold)
Stay warm!
Forecast:
Tuesday: 31 19
Wednesday: 31 22
Thursday: 28 26
Friday: 26 18
Saturday: 31 21
Also, just to clear things up, the low temperatures are for the morning of the day. That means there is the morning low, and then the high. For example, the low on Tuesday would be Tuesday morning, not Wednesday morning. Not sure if you knew that, but this is just to clear up all confusion.
December 14, 2008
Predicted: 31 23
Actual: 30 26
The real cold has begun! Friday was cool, Saturday was cold, but today was really cold. And this week is gonna be RAW. This will be the longest, coldest stretch of weaher since 1990. For many of us, that means this will be the coldest Seattle weather we have faced in our life. People are all worried about whether it will snow or not, and I am too, but I'm excited about it being cold too. There is a little pond near my house that frequently freezes. I remember when we had an extended period of cold in 2004 and I could walk on it. I was in 7th heaven then. There's nothing like walking on something you see liquid all the time. I'm expecting to be able to walk on it again this year, and maybe even go ice skating. It's really shallow, so if I fall in, I will be EXTREMELY cold (and actually at a risk for hypothermia since the water will freeze to me after I get out) but I won't drown.
Monday and Tuesday will be frigid but dry and sunny. Nuff said.
Wednesday is where it gets interesting. A low pressure system drops down from the north, and with the cold temperatures in place, all precipitation will fall as snow, except maybe a mix over the coast. We can expect 3-6 inches of sticking snow with this system. It will stick to the roads as well since they are very cold. This storm could close the schools for sure, and Wednesday could very possibly be your last day of school for 2008 if winter break starts next week for you. Not guarenteeing anything of course, and you know how hard snow is to forecast, but at least we won't have to worry about temperatures being on the fringe.
Thursday will be a day of residual snow showers, much like today. Friday will be dry and probably even more cold than tomorrow or Tuesday. Another arctic air mass will dive southward, and this mass will be larger and colder than the one we are into right now. Expect temperatures in the mid to low 20s. Brr!
The weekend, and Sunday in particular, is where things get really interesting. A large Pacific storm will drop from the NW and come in just south of Seattle. This is nearly a perfect track for heavy snow in Seattle. Although the air mass will be warmer and snow isn't as sure of a bet as Wednesday, the snow will be a lot greater in quantity because this Pacific storm will have a lot more moisture than the one expected on Wednesday. Also, since it is coming just south of Seattle, winds here should be from the north, which would keep temperatures from warming too much and in fact just draw down more cold air. I am not saying this forecast is definite at this point, and models have been flip flopping around with it a lot. If the event happened as computer models show it today though, the Seattle area would see heavy snow with totals anywhere from 6-12 inches down to sea level. Cross your fingers, do some snow dances, but don't jinx it. The trick is balance. Appease the Snow God, but don't annoy him.
Forecast:
Monday: 29 20 partly sunny
Tuesday: 29 19 mostly sunny
Wednesday: 30 25 light snow
Thursday: 31 26 snow showers
Friday: 25 16 bitterly cold and sunny
December 13, 2008
Predicted: 36 22
Actual: Too early yet...
The initial storm has passed. Here are some of the peak gust from this storm as of 4 P.M. yesterday. The winds were definitely not over by this point, but this is the only data I could find.
Destruction Island: 95 mph
Forks: 69 mph
Hoquiam: 58 mph
Alki Beach: 52 mph
520 Bridge (Seattle): 51 mph
Oak Harbor: 49 mph
Seattle (Magnolia): 49 mph
Friday Harbor: 47 mph
Shelton: 46 mph
Seattle (Sand Point): 46 mph
Tacoma/McChord AFB: 46 mph
Bremerton: 45 mph
Tacoma/Gig Harbor (Narrows): 45 mph
Seattle (Sea-Tac): 45 mph
Everett: 43 mph
Winds were generally what I expected, except at Destruction Island. Destruction Island is a coastal headland that commonly gets some of the strongest winds in Washington. Almost hitting the triple digits though... that really demonstrates the power of this storm. As I think I said before, the upper level orientation of this storm wasn't favorable for extreme winds in the Puget Sound area, it was much more favorable for the coast and Strait of Juan de Fuca. When a storm is coming in from the SW (like most of our windstorms) a very strong gradient develops on the southern side, and the upper level movement of the storm helps to enhance the winds since the surface and upper-level winds are working with each other. With this storm, the gradient was there, but the upper-level winds were actually coming from the NW. Because of this, the strongest winds in many places occured after the low had passed, something pretty unusual, although not that unheard of, especially for the Strait of Juan de Fuca, which commonly receives strong surges of NW winds after the passage of a low pressure system. Still, it a sub 980 low were to come where it did but come out of the SW, winds in the I-5 corridor would have been MUCH stronger, with gusts as high as 80 mph. Still, the winds here were very impressive, and Lake Washington was quite a sight!
I don't mean to be cocky or anything, but I forecasted this storm better than EVERYBODY else, even the NWS and Cliff Mass. However, there are two things that are different with my situation. First of all, I got lucky. I simply chose to follow the right forecast model. Part of this was from thourough analyzation of satellite pictures, models, and historical situations, but still, I got lucky. Second, places like the NWS HAVE to issue winter storm warnings when there is a remote possibility of significant snow. If the low pressure system tracked further south, places in Western Washington could have seen up to 10 inches of snow. If this occured, I would probably get some eggs thrown at me on school on Monday. Imagine what would happen to the National Weather Service or TV stations.
But the bottom line is, I was right and they were wrong. :)
Now... the cold.
You probably haven't thought of 37 degrees as warm. That was the temperature at Sea-Tac this morning. However, that is probably the warmest it is going to get all week. We have a VERY cold week ahead of us.
Today, we do have a fair shot at getting some snow. An arctic boundry will drop south from Canada, and this could bring trace-3 inch amounts in the Puget Sound area. Forecast models this morning are weaker with this feature than before, but I still think that it will manage to drop some precipitation (probably graupel or snow) before it is all said and done. After this front passes, it will get really cold. Whatever snow there is on the roadways will freeze. Great news for students not wanting to go to school on Monday, and bad news for those trying to get to work.
Sunday, it will be a lot colder and a little drier. There will be some snow showers as a low pressure system to our south destabilizes the atmosphere, allowing for some pop up showers. While these showers will be few and far between, one thing will be certain: they will be in the form of snow. Let's hope a huge one hits the superintendent's house!
Monday-Wednesday next week is the real cold. Highs will be in the 20s, and lows will be in the teens. One feature that the models have been consistent with is a low pressure system dropping down from Canada. If this occurs, precipitation WILL be in the form of snow. For once, it is an easy forecast! We will still have to see if it happens, but if there is moisture then, it WILL fall in the form on snow. No questions asked.
After that low pressure system, another very cold arctic air mass will slide into Western Washington on top of the one we already have.
Long range forecasts suggest that we will be cold for a long time. Some long range models have hinted at HUGE snowfalls in Seattle on the weekend before Christmas. However, if we can't predict snow 6-12 hours in advance, what makes us think a week is like shooting apples in a barrel? Still, it's exciting. Bring on the snow!
Forecast:
Sunday: 31 23 few snow showers
Monday: 27 18 mostly sunny
Tuesday: 24 19 partly sunny
Wednesday: 30 26 snow
Thursday: 29 20 snow showers
December 11, 2008
Predicted: 47 39
Actual: 45 41
Wow! This is probably the most difficult forecast I have ever done. A TON has changed since I wrote last night. Right after I wrote about high winds for the Seattle area, new forecasting models came in and showed a whole new solution... the low coming into the SOUTH of our area. This would just bring us a lightish northerly wind... and increase our chances for snow. A winter storm watch was issued for Western Washington, and a wind advisory was not issued. However, the new model runs of the 00 NAM-MM5 model at the UW show an entirely different scenario: the low coming back up to the north again, and deeper. One way to tell how strong the winds will be is to look at the pressure gradient. A great measure of approximate wind speed is to look at the gradient between Portland. The NAM model shows a pressure gradient of 20 mb! That is huge... the biggest since the December 2006 Hanukah Eve storm. On the other hand, the new GFS model keeps the old scenario, with the low coming in near Hoquiam and weaker. This would give us weaker winds, and a better chance of snow. Personally, I would like higher winds over a increased snow chance, because I don't think that we would get snow in either scenario. The NAM model though... if that were to follow through there would be some very strong winds. One thing of note though... the movement of the storm is not conductive to a strong southerly wind. The storm is dropping in from the northwest, and this means that the upper level orientation of the storm will not match the surface level, and the winds will likely not be as strong. Still... 20 mb is an absolutely ludicrious pressure gradient. A lot will change between now and then, but this new solution just indicates how unique and complex this setup is. The models should be locking on something less than 24 hours out, but they haven't. Whether all hell breaks loose or nothing happens, there will be surprises that weren't forecast. That I can guarentee.
The high winds for the coast and strait are still looking on track. Waves on the coast will approach 30 feet!
Now to the snow... after the front passes, a convergence zone will likely develop in the wake of the low. With the cool and unstable air behind the front, expect snow levels to be dropped to the surface... or lower.
Just kidding... but seriously... this zone could spread heavy snow in a narrow band between Seattle and Everett. The placement of convergence zones is extremely hard to forecast... so the whole central/northern sound area should keep an eye out for snow.
After Friday night, the airmass will turn significantly cooler. Not yet super cold though. Showers will still be around, and these could be in the form of snow or a rain/snow mix. Saturday night, colder air will filter down from the north. Sunday, an arctic front may drop a quick inch of snow or two around the puget sound area. After the front, it could freeze solid. Next week will be extremely cold, with highs as low as the low to mid 20s and lows into the teens. More on all this later. The windstorm is the main focus for me right now, and I have a lot of homework to do as well. Stay tuned. :)
Forecast:
Friday: 42 33 stormy
Saturday: 36 22 snow showers
Sunday: 29 17 few snow showers
Monday: 25 18 sunny
Tuesday: 26 19 sunny
December 10, 2008
Predicted: N/A
Actual: 48 44
Wow! It has been a long time since I have posted. The weather has been SO boring that I have nearly forgotten about this group. But we have a LOT to talk about and a lot of action to occur over the next couple days. First, let's talk about Friday. As of now, there is a developing low pressure in the Gulf of Alaska that is going to drop to the southeast, pretty much right over western washington. There are three things this storm will do... it will bring 1-2 FEET of snow in the mountains above 1-2000 feet, it will bring a lot of wind, and it will usher in a maritime cool airmass, which in turn will usher in an arctic continental airmass.
First, let's talk about wind. I've been watching this system for some time and have been really intruiged by it. Models are switching rapidly but they've been remarkably consistent in general handling this storm. This storm will be driven by a strong jet stream and will represent the boundary between two strongly contrasting air masses. All these things support the cyclogenesis, or "bombing" of this low pressure system. Basically, this means that the low pressure system will intensify rapidly before it makes landfall. On wind, models are saying perhaps 70 knots sustained in isolated spots over the ocean. That's hurricane force. Let me repeat. That is hurricane force. The pressure of this storm, although not that deep (980-985 mb) is very compact. This means that the pressure changes are more pronounced, and there is a tighter gradient. The tighter the gradient, the stronger the winds.
The coast has a high wind watch for sustained winds of 30-50 mph with gusts to 65. There is also a high wind watch for the northern interior, with winds strong but a little lesser, maybe gusts from 50-60.
Nothing has been posted for Puget Sound so far, but there has been talk about maybe posting an advisory. People are forecasting winds of 25-35 mph with gusts to 45. I am going to go ahead and forecast higher winds though, winds 25-40 with gusts up to 55 and perhaps 60. I'm going to do this for three reasons: 1.) the low pressure system is moving very fast, which tends to speed up wind speeds. 2.) the low pressure is coming in very close proximity to Seattle, just a little north, which would put Seattle on the stronger southerly side of the storm. 3.) The flow may produce a mesolow on the lee side of the Olympics, which would speed up winds in Puget Sound and Hood Canal.
A lot can change between now and then, but for Puget Sound, the highest winds are forecast between 4-7 P.M. on Friday. Following the passage of the low pressure, storm force winds are possible over the Straight of Juan de Fuca and northern Puget Sound. These winds will be very strong (50-60 mph gusts) and WILL cause damage. Whether or not Seattle gets winds as strong as I am forecasting, high winds in the Strait are CERTAIN.
Snow: This system is going to bring gobs of snow to the mountains, which is great new, but snow levels will likely be too high for snow in the lowlands. Some snow may mix in, but it will not stick. If it were to snow anywhere, the higher elevation by Hood Canal would be a good bet.
Cold: Cold air will filter in behind the front on Saturday. Saturday will be cool, but not frigid. Highs will struggle to make it into the upper 30s, and with a few random showers about, most would be snow, especially at higher elevation. Saturday night and Sunday, a reinforcing shot of cold air may come in. An arctic front may bring some snow to sea level. Arctic fronts are weak and do not hold much moisture, but they can drop a quick inch of snow, and then freeze it solid in the storm's wake. Remember the Monday Night Football game in 2006? Seahawks vs. Green Bay? That snow fell to an arctic front, and once it passed, the arctic air froze everything solid in the storm's wake. We could see something similar to that, but it's not a sure bet. It's a long ways out. Forecasting models have been trending towards it, though. We will see what happens.
What happens after this?
We get VERY cold and dry. Highs next week will struggle to reach freezing, with lows into the upper teens and low 20s. If you have sensitive plants, protect them. Watch out for your pets too. Interestingly, models keep us cold and dry for a while. It is WAY to early to tell, but some more widespread lowland snow may occur at the end of next week.
Whew!
Stay tuned...
Golly Gee! I almost forgot!
The convergence zone!
The convergence zone could bring SNOW Friday night/Saturday morning in the usual N. King S. Snohomish county areas. The snow could be fairly decent if the zone lasts for a while. Isn't weather so exciting?
Forecast:
Thursday: partly cloudy 47 39
Friday: stormy, mountain snow 41 35
Saturday: cool, rain/snow showers 37 27
Sunday: cold, few snow showers 33 23
Monday: REALLY cold and sunny 30 19
GREAT LINKS:
Scott Sistek's and Cliff Mass's weather blogs. They are chalk full of information. Google them. They are a GREAT resource.
http://www.komonews.com/weather/blog
http://cliffmass.blogspot.com/
This is a very difficult forecast to make. First of all, tonight and tomorrow, it will be rainy and windy. A winter storm warning is in effect for the mountains for 1-2 feet of snow. A typical winter storm... that's pretty much it.
The forecast for Thursday is SO complex and SO complicated. Usually, as time gets closer, models converge on a situation. Here, they have deverged. One model, the GFS, brought a 963 low into central Vancouver Island two days ago for Thursday. The NAM brought a weak 1000 mb low into SW Washington. That's a huge difference in strength, and a huge difference in track.
Now the models look like they have finally converged on a scenario, although they still are far from lining up. They take the low pretty much right over Seattle at 985 mb. The NAM is still weaker and the GFS is still stronger... but at least there is some agreement now.
All this confusion is because of different zones of low pressure forming around this swath of moisture. The GFS first brought one big low pressure center and the NAM brought three really close together. Now both of them bring two.
While this while relax the wind, it could make for some extremely heavy snow in the mountains. It could even make for some extremely heavy snow in the north interior. The NWS says NOTE THAT ON A
MORE SOUTHERN TRACK WE WOULD ALSO NEED TO KEEP AN EYE OUT FOR THE
POSSIBILITY OF A VERY HEAVY DUMP OF LOWLAND SNOW NORTH OF THE TRACK
OF THE CENTER AS STRONG EASTERLY FLOW IN THE LOW LEVELS GETS OVERRUN
BY TONS OF MOISTURE IN A DEEPENING STORM WITH WET BULB COOLING IN
THE LOWER LEVELS AS HAPPENED ON NOVEMBER 19 1996 AND AS HINTED AT BY
MODEL OUTPUT STATISTICAL SNOW AMOUNT GUIDANCE OFF THE 12Z AND 18Z
GFS.
So if the low tracks further south, we could see some snow!
The whole thing is very confusing though, so stay tuned!
Deceber 25, 2008
I know its been a while since I have posted. I've been extremely busy with last minute shopping and Christmas stuff (not to mention tired out from all the previous weather). But I decided I better keep a regular schedule if I want people to keep reading my blog. Now that the snow for the lowlands is pretty much over, I'll resume to a more regular routine.
Its late and I'm wiped out, but the main story looks to be less snow down here, but a WHOLE lot of mountain snow. Friday/Saturday could have urban flooding as a lot of the snow melts and .5 inches of rain falls on top of it. The mountains meanwhile are going to get hammered. By Tuesday, it is possible that 5 FEET of snow will have fallen in some spots. Alpental opesn tomorrow, and I hope to be the first one on the slopes. Good night!
December 20, 2008
Predicted:
Actual: (too early again)
This is going to be crazy. This storm will be life-threatening.
As of 11:17 AM Saturday morning, the storm is moving faster than expected. New radar shows the leading edge of precipitation slowly making its way to the NW, with the leading edge near Olympia right now. This storm will dwarf the convergence zone we had on Thursday. Although snow totals here should be about the same, there will be NO question in your mind that this storm was clearly the greater of the two.
First, let’s get to some extremely low temperatures that occurred early this morning. This morning was EXTREMELY cold throughout Western Washington, due to the arctic air that was already in place and strong radiational cooling (cooling at night where heat radiates back into space). I never thought I would see this in my lifetime, but some places in Western Washington actually had lows below 0 degrees! Arlington had a reading of -3 this morning! Seattle had a low of 14. All this does for us is to up the chances that all precipitation will be snow. The cold temperatures alongside the faster-moving front confirm that we will see a mainly snow event without much sleet or freezing rain north of about the Tacoma area.
I’m typing this up on Microsoft Word to see if I can post pictures, which I haven’t been able to do on Facebook. Then I will copy this text and put it into the recent news section of my group on Facebook: we will see if the photos work! If they do, you probably will learn a lot more and get a greater in-depth look at what we are expecting as far as snow and wind.
This is a high-confidence scenario. Models have been remarkably consistent with the winds and precipitation, so there should be no questions about who will get the heaviest amounts of snow, how will get medium amounts, and who will get little or even none.
First, let’s break down the weather warnings in Western Washington.
Oops so that picture didn’t even work on Microsoft Word. What we are looking at is a BLIZZARD WARNING for the Olympics, Western Strait of Juan de Fuca, North Coast, West Slopes of the North Cascades and Passes, and West Slopes of the Central Cascades and Passes. This means that heavy snow with sustained winds over 35 mph is occurring or imminent. This is life threatening folks. Do NOT travel in this. You could die. Actually.
A lesser but still significant WINTER STORM WARNING is in place for all of Western Washington and Eastern Washington, apart from the Cascade foothills and Sequim where little or no snow is expected. Amounts here could range from 2 FEET by the Kitsap peninsula to 3 inches near Bellevue.
Why the huge range?
This storm is packing some potentially catastrophic easterly, downslope winds. Depending on where you live, these winds could either act to increase the amount of snow you will receive or decrease it. People living on the Kitsap peninsula will have these winds slam into the Olympics, creating an orographic (topographically induced) effect on snow totals, pushing them up. The foothills will have these same winds, but much stronger. However, they will be traveling DOWN mountains instead of traveling UP them, acting to decrease the snow totals here. Seattle will be between these two areas as far as snowfall is concerned, with anywhere from 3-8 inches likely. Sequim will be shadowed by the Olympics much like Seattle was on Wednesday, so they will see little, if any snow. I laugh at Sequim. :P
However, this storm is no laughing matter. This is SERIOUS. The media hyped up the storm earlier in the week about the same amount as this one. These storms are TOTALLY different. This storm is MUCH, MUCH stronger. Can’t stress that enough. Let’s see if I can post a UW model run of the amount of snow we are expecting.
As you can see, the highest amounts look to be in the mountains and on the Kitsap peninsula, with the lowest amounts by Sequim and the foothills, especially Enumclaw.
Alright, let’s get to wind.
As much as snow is a concern, my biggest concern is wind. Winds could reach HURRICANE force in places near the foothills. Here are some MM5-GFS model runs for the winds. Notice how they get stronger, peaking early Saturday night/early Sunday morning.
As you can see, the winds intensify through the afternoon. This last frame, which shows the winds at 2200 hours local time (10 PM) shows sustained winds of over 50 knots near the foothills, especially those like North Bend and Enumclaw. The winds should remain this strong until about 1 AM, when they will start to die, although still INCREDIBLY strong. I’m going to make an attempt to convince my mom to drive me out there at night so that I can experience and get some video footage of this. My mom is probably going to say no, and for good reason. This is very dangerous. Still, if I do go, you can bet I will be out there reporting with 80 mph gusts behind me and windchills of -25.
Cliff Mass says that the models often overestimate the strength of these winds, and forecasts sustained winds of 34-45 with gusts to 60-70. I’m going a little higher, with sustained winds 40-50 with gusts 70-80, possibly as high as 100 in isolated spots.
These winds will knock out power and cause extreme damage to foothill locations, especially those of MAPLE VALLEY, NORTH BEND, and ENUMCLAW (Enumclaw is generally the windiest foothill).
With the arrival of high winds and cold temperatures comes two other concerns: Frostbite/hypothermia and Carbon Monoxide poisoning. Windchills will approach -25 degrees Fahrenheit and power could be out for weeks. DO NOT PUT A GENERATOR IN YOUR HOUSE TO MAKE HEAT. PUT IT OUTSIDE. Carbon Monoxide is a colorless, odorless gas produced by combustibles. Remember how many deaths occurred in December 2006 because of our windstorm? This event is less widespread and people living in the foothills are more accustomed to these events, but I hope that the message gets out that Carbon Monoxide can kill you and you should NEVER be in an unventilated area with a generator or other combustible appliance.
That’s pretty much all for now. The extended looks cool and we may see some more snow, but not an event as dangerous as this. Long range models even showed some more arctic air masses working their way down through here next week. Hang on to your hats…
On a lighter note, here were some of the temperatures recorded this morning.
Univ of Washington 19
Mountlake Terrace 13
Lake Forest Park 9
Woodinville 8
S Everett 8
S Whidbey Island 8
Marysville 3
Arlington AP -3
Looks like pics didn't show, oh well. Can't have everything in life.
December 19, 2008
Predicted: 27 18
Actual: 27 20
Snow totals from this event can be found here: http://www.facebook.com/group.php?gid=33875355514&v=app_2373072738#!/topic.php?uid=33875355514&topic=5804
I really needed a breather yesterday. That's why I didn't write a forecast. I love this group, but enough is enough (Emmett Akeley knows this for a fact). Of course, the forecast for the next few days is as challenging as the last, maybe even more. We will have a very warm Pacific system overrunning frigid air, and this could have a variety of effects for Seattle.
First, let me give my opinion on the weather events over the past couple of days, including what I did well and what I could have done better.
For Wednesday, the schools should have never canceled. The lack of snow was expected. We were supposed to see an inch at most, probably less. The problem is that the media ALWAYS overhypes snow events. When there is a CHANCE of snow, the media makes it seem like snow is CERTAIN. Of course, meteorologists have to do some things too. And I learned some lessons from that storm.
I should have emphasized the fact that we probably wouldn't see snow more. People were surpirsed that we didn't see snow but I wasn't. I thought I had made that clear. But looking back at my forecast, I realized that I really hadn't. So in the future, I will emphasize the FACTS about snow more, cause the media usually only acts to screw things up (cause that is how they make money, right? By having names like "Storm of the Century" and captivating the audience so they get more viewers). Next time, I will try to make this more clear.
Also, this storm reinforced my belief about convergence zones. You can often predict that they are going to happen, but it is hard to predict WHAT will happen. Wednesday night, while I was forecasting 1-5 inches of snow, Fox was forcasting 1/10. We were both wrong. Totals were more like 3-8 inches. The funny thing is my initial forecast was the most accurate... 3-6 inches. Funny how that works. People paint an intial forecast, then freak out as details change, but if they stayed with the initial forecast, they would have been more correct. I'm not saying that longer range forecasts are more accurate, in fact they never really are because model errors are magnified over the long run. Still, that's how it worked yesterday, even if it was by chance. That's called irony.
Remember how I was saying it wasn't really a convergence zone? That was exactly what happened. Instead of two winds colliding, the warmer southerly wind, since it was less dense than the colder northerly one, lifted over it. This lift created snow showers. This zone stayed over us for quite some time, dropping anywhere from 3-8 inches of snow over the Seattle area. I did a better job then most of forecasting this, but still, the NIGHT before, all models were saying we would get about 2 inches at the most. I got kinda lucky, and although there is definitely some skill, I just chose the right side. In reality, just cause I forecasted this event better than the NWS or tv stations doesn't mean I'm somehow more skilled than them. I most certainly am not. I'm a kid, and they are professionals. Except for Q13 Fox. They just suck in every regard. =D
Looking at the snow totals, it looks like the snow lottery winners in the Seattle area were Beacon Hill, with Amie Szeto from Beacon Hill reporting a little over 8 inches before it was all said and done. Of course, we had an accidental report of 4 feet from Sammy Lesnick, and Jamie Daudon posted a grand total of 60 feet from the Arctic circle, but these reports are questionable at best. Generally, the highes snow totals appeared to be right around Beacon Hill and Mt. Baker. Places further north, like Wallingford and Magnolia, only got 3-4 inches. Since the temperatures were below freezing all day, there wasn't that much of a variation in snow amounts with elevation (for once)
I was up all night of course waiting for snow... I woke up at 3 A.M., too excited to fall asleep again. I looked at the radar and saw a convergence zone (an actual one) forming right over my house. As it got stronger, it got wider, and the snow intensity increased. One common misconception that I have seen is that we received hail. We recieved something similar, but not the same. We received snow pellets, which are extremely common with convergence zones, actually more common than snow itself with narrow, intense ones.
At around 5 A.M., a HUGE lightning flash struck extremely close to my house... probably 40-100 yards away. There was no pause at all between the lightning and thunder, and the flash was nearly blinding. At first, I thought it was a huge power surge. It then began to snow very heavily. Shaken but not stirred, I continued checking the radar and chatting on facebook (which in retrospect was probably not smart at all). A minute later, another lightning flash struck very close to my house. This one was a little further away, but still extremely loud. At that point, I shut off my computer and all electronic appliences. I didn't want a power surge to ruin my computer, and I didn't want to get indirectly struck because I was holding an AC/DC appliance. I walked outside real quick (boy I am full of dumb ideas) to see if I could feel the charge in the air. I could, and my hair started to stand up. I actually think I explain somewhere in the discussion topics another experience with static electricity in which I almost get struck by lightning. It should be under "unusual weather experiences" or something. If it's not or you want to hear more, just write on the wall and I'll tell the story. :)
Alright... so let's get to the forecast... oh man... just remember that if I get this oen wrong, the fact that I got yesterday cancels out any egging opportunity. Sorry Max Elvis David and Christopher Swanson, but you may have to be eating omelets for the next 6 months.
Aight...
So... the forecasting models show three possible major weather events here. First... a major windstorm could be on tap for the foothills of Western Washington. Models have slacked off a little on this one, but some are still adamant (the GFS) in bringing SUSTAINED winds of over 60 mph to some foothill locations (most notably, North Bend) with gusts approaching 100 mph. This would be an extraordinary wind event. Meanwhile, winds in Seattle would be much less, with gusts maybe over 45 mph. I'll talk about timing later, but the winds appear like they will be the worst late Saturday night and early Sunday morning, as the low pressure system approaches from the west and high pressure remains centered in Eastern Washington. This event has some serious potential, and you bet that I will be up in North Bend to capture some footage if we do indeed have the high winds that some models are forecasting.
Next... snow
We could see a much more widespread snow event. Seattle proper could see 1-6 inches of snow, and places like Hood Canal could see as much as 2 feet! Places like West Seattle will see much more snow than places like Bellevue. The further east you go, the lower the amounts will be.
Why, you may ask?
When air flows down, it warms and dries. It should still be very cold (since the air in Eastern Washington is so cold) but it should be VERY dry. This dry air will limit snowfall in those areas. Of course, Seattle is right between the areas where little snow is expected and where a ton is expected. So expect a steep gradient.
These overrunning events are extremely hard to forecast. Be on the lookout for meteorologists pushing back the start times for precipitation. This usually signals that the total snow accumulation will be rather limited. We really don't know how much snow we will get until the storm is actually on top of us and we can see how this storm interacts with the local terrain.
Third, we could see freezing rain...
And I just heard on the radio that Paris Hilton's house got broken and 2 million dollars worth of jewelery got stolen. Tell me why Paris Hilton has 2 million dollars worth of jewelery and people who actually do stuff, even if it's flipping burgers, live in poverty? Oh well...
Sorry. Back to the freezing rain, this will be a classic overrunning event, where warm Pacific air overruns cold, arctic air. What you can get is rain forming because the air aloft is warm, but then freezing as it hits the ground because the ground is still below freezing. Too early to go into depth about that... but it could happen.
These overrunning events are extremely difficult to forecast... but I have confidence that we will at least see some snow before it is all over. I may do an extended forecast later, but I've spent about 45 minutes writing this, and I'm ready for a break. The extended looks cool, but not cold, although we may see some colder air filling in after Sunday, which would again freeze snow to the roads, although not a hard freeze.
Jeez... this is a pretty good workout. I hope I don't throw up... jk
As of 12:34, pretty much all of Western Washington has a winter storm watch, and the eastern lowlands (mountain foothills) have high wind warnings.
December 17, 2008
Predicted:
Actual: (too early)
So... as soon as the new weather models came out last night, I really wanted to write a new forecast. I was really tired though, so I didn't. The new models showed two things: first, they showed an even stronger snow shadow over Seattle. A snow shadow is where air sinks and dries off of a mountain range (in this case the Olympics), leaving little moisture for areas downwind of them). Second, they showed warmer temperatures as the low pressure system moved further north than expected, bringing southerly winds with them. I had that "sinking feeling" that A.) There was going to be school tomorrow B.) I would end up with an egg on my face before the week was through and C.) I was going to have to suddenly do a lot of homework.
Luckily for me, the school districts don't know about the UW atmospheric sciences page! (I highly suggest you check it out, just google it and look at the forecasts)
Really though, I wasn't that off. Snow totals were an inch less than I expected, and I expected an inch.
I can't stress this enough though. DON'T GIVE UP HOPE!!! I EXPECT to see snow tonight, especially in north Seattle. A convergence-zone thing will occur, expect it's not really a classic convergence zone. It is more akin to a deformation band, which is diverging air aloft and converging air at the surface. Main point is... at around 7 P.M. tonight, temperatures will cool back below freezing and snow will begin. The band of snow will be centered in N. King/S. Snohomish counties, but it will slowly drift south.
Convergence zone snow amounts are extremely hard to predict. I actually believe that the worst case scenario would leave a foot in Seattle (best case for me). Anywhere from 1-5 inches looks more likely.
Alright I'm gonna go bench 5 Billion tons of weight right now, but I'll make another update when I'm done. Just wanted to explain what is going on, and that snow is still in the forecast.
Alright, it's 6:04, and I'm back. First, before I talk about the weather, I want to share a very funny story about my weightlifting. I had not had anything to eat this morning, so my blood sugar level was very low. I also had a VERY intense workout. So intense that I threw up. Once I started feeling nausea, I headed to the elevator to get on a floor with a restroom. I started feeling REALLY bad in the elevator. I hopped out on the 8th floor, looking for a restroom, and not having the sense to just look for a trash can (my mind was racing at that point). Suddenly, right in the middle of the sports bar, I threw up. I covered my mouth with my hand, still not thinking about the obvious; a trash can. A lady behind me saw me, had a startled look, and walked away. Suddenly, more volumes of gastric fluid lurched up my esophagus. I couldn't hold it no more. A plethora of (well, I don't want to gross you out... it wasn't too bad). Then, a little asian lady working at the counter got mad at me. She was like, "You throw up? Dummy!" I felt kinda bad and offered to help her, but I think she was worried I would throw up on her and make matters worse. I felt extremely sweaty, not only because I had just thrown up but because everybody was looking at me. At one point, a college kid with a hoodie walked out of the elevator and gave me the most despicable, contemptuous look. It was bad...
But hilarious in retrospect.
What does this have to do with weather, you might ask?
I wouldn't have been at the WAC weight room, and wouldn't of had this great story to tell, if the forecast wasn't so hard!
So what happened?
The problem in Seattle is that even when there is a slight chance of snow, the media hypes it up SO much. If there is a 50 percent chance of snow, they will say it is certain. And when that 50 percent doesn't come, the only ones not surprised are the meteorologists. I'm frankly not surprised at all that we didn't see any snow today. The Olympic snow shadow was in full effect today, blocking out ALL moisture headed towards our area. I thought it would block out most. I was only a little off, but since we are talking about snow, that effect gets magnified. It was also warmer than expected due to the low pressure system tracking more to our north, which brought a warmer southerly wind as opposed to a colder northerly one.
Tonight though, I am much more confident that we will get snow. And here's why...
Now, the Olympics will not act to limit our snowfall. They will help create it! But how, you might ask?
THE PUGET SOUND CONVERGENCE ZONE!!!
This nightmare for forecasters but hero for kids forms when a NW wind hits the Olympics and splits. One part goes into the Strait on Juan de Fuca, and another part goes through the Chehalis Gap. They meet in Western Washington, and when they meet, there is often precipitation (and often snow). The most often place for the PSCZ to meet is right on the Snohomish/King county line. Take a look at the radar right now. You will see a stationary band of snow from about Lake Forest Park north. This is the convergence zone. Over the course of this night, the convergence zone will shift down south, dropping anywhere from 1-5 inches of snow with it. This is a pretty wide range, and it is really hard to predict where the convergence zone will go. We could even get over 5 inches. And, of course, there is always that possibility that we could get none. But all in all, I am MUCH more confident that we will get snow tonight with this convergence zone. The only things that could really mess us up are if the convergence zone stays north and the air mass doesn't cool off as much. All models are in agreement that those things will not happen though.
Here's my time frame:
7-11 P.M. The convergence zone will be in full force, especially over northern king and southern Snohomish counties. Some places to the south will see light snow or mixed snow and rain showers, but these will increase in intensity and snow percentage due to the convergence zone sliding south and temperatures cooling.
11 PM-4 AM: The zone will shift south and stall over the Seattle area, bringing some snow with it.
4 AM-7 AM The zone may shift even further south, towards Sea-Tac or so, before finally fizzing out.
I hope I am right. If I'm not, I am going to be SCREWED tomorrow.
Do a snow dance... for me =)
No extended forecast tonight... do you really care what the weather is going to be like in a couple days? I'll continually update this page as new information comes in.
So the new weather models came in. And they brought some news with them. Drumroll…
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The snow still looks on track! A few details have changed though. The snow looks like it will arrive much later in the evening (well technically tomorrow morning). One model, the GFS, says the snow will arrive in Seattle at 3-4 AM and last for a couple hours, dropping approximately 1-2 inches of snow here. Another model, the NAM, says that the snow will arrive in Seattle at 6 AM and last a little longer with some higher snow totals… anywhere from 1-4 inches. I can’t stress this enough. Don’t freak out that it isn’t snowing now.
In the event that there is school tomorrow, bring eggs. Throw them at me. Or bring something to make fun of me. It would be hilarious. Especially people in band class. That would be AWESOME!!!
However, if I’m right, ya’ll gonna respect my authority. And I still think I’m we are gonna get snow tomorrow.
As for which model to go with, I am going with the NAM. This could complicate matters again because of timing… so again I don’t know what the school district is going to do. In any event… snow will stick to the roads.
Charlie Phillips thinks there will be snow, and Charlie Phillips thinks that there will be a complex decision to make by the school district. If all goes well though, there should be no school on Thursday.
Thank you God.
Updated at 10:17 P.M. Wednesday
I forgot to mention that even if we don't see a convergence zone, we could see a few pop-up showers that could drop some zone. In fact, the radar shows some headed towards us right now, but they also look to be fizzling out.
Talk about high stakes.
Hope to not see most of you tomorrow...
December 16, 2008
Predicted: 31 19
Actual: 31 20 (So close...)
Get ready...
Its been cold, but its been dry as well. There were probably fewer clouds in the sky than fingers on my hand the last two days. But here comes the moisture.
Here's a horrible joke that doesn't make sense at all.
Q: What do you get when you mix moisture and cold temperatures?
A: Snow!
That may be the worst joke I've ever told, and believe me, I've told some pretty bad ones. That wasn't even even a joke actually. That was just a statement of blatant obviousness determined to be a joke by yours truly. Maybe because it just fit into that form so perfectly, or maybe because I just love telling horrible jokes that only make sense literally.
Alright enough with the trigonometry... let's get off these tangents.
Tonight, clouds will be on the increase as a low pressure system drops down from Canada. This is the southern fringe of the system that will give us snow tomorrow.
Alright... enough of this cloud gibberish... let's get down to what matters.
Snow should first start in the northern zones at around 1 A.M., save perhaps a few isolated flurries before that. The snow should work its way into the Puget Sound area by 6 A.M. However, the snow in Seattle should be rather limited at first because of a snow shadowing effect off of the Olympics. So Seattle may get an inch from this storm, maybe more, maybe less. However, later in the day, a convergence-like zone will form north of Seattle, which could bring some snow there, and it will later drift down south through Seattle. As I believe I said yesterday, this could act to balance snow totals out. All in all, the Seattle area will probably see anywhere from 1.5-5.5 inches of snow. However, these amounts could be significantly higher if that convergence zone stalls over Seattle and is stronger than currently expected. Any snow that falls will stick to the roads. The roads are frigid and the temperatures will be at freezing or below. This could complicate the morning commutes for the rest of this week, especially Thursday and Friday.
All you students are probably wondering about school. Frankly, for Wednesday, I have no idea what the district will do. There should be some light snow in Seattle by 6-7 A.M., but not enough for it to really a problem on the roads. And the districts usually make their decisions at 4 in the morning or so, so there wouldn't be any snow on the ground then.
It all comes down to if the district decides to play it safe and foresee the snow situation, or if they take a risk. For that, I can only provide the forecast. The district, as you all know, has a mind of its own.
Thursday will almost certainly be a snow day. Friday should be one too, as the temperatures on Thursday will not climb above freezing. In fact, they will stay in the mid 20s. Even if Thursday is not a snow day, there is a small chance of a snow day Friday as one model showed a weak arctic front dropping down from the north, which would drop a quick inch of snow or so, and then freeze it solid to the roads. Only one model (NAM) showed this though, so the probability of this happening isn't terribly high.
Sunday, the models bring some more snow into the area. It doesn't look like quite as much as before, but it is really to early to pin down any amounts. I will have to wait a day or maybe two before I can begin to make any reasonable estimates.
Also, the extended now looks cool, and not cold. If the models are correct, we should be under the influence of a maritime polar airmass, not a continental one, as the trough in the jet stream that is giving us all this cold weather shifts over to the east. This would be a great pattern for snow to the mountains, with snow levels around 1,000 feet. That's about 1,000 higher than it is right now though.
Stay warm and do some snow dances!
Forecast:
Wednesday: 34 28 snow
Thursday: 31 27 snow showers
Friday: 27 18 mostly sunny
Saturday: 25 17 high clouds
Sunday: 32 25 snow
December 15, 2008
Predicted: 29 20
Actual: 30 20 (what now Jeff Renner)
Today was pretty cold. The coldest we've been in two years (we had a couple of days in 2006 that were about this temperature). It was cold, but it was sunny. There was hardly a cloud in the sky. That's usually the way it works in western washington. When we are cool, we are usually under the influence of a polar maritime airmass (storms coming from the Gulf of Alaska). But for us to get cold, we have to be under the influence of a polar continental airmass. And these airmasses are brought to us by domes of high pressure, because that is what arctic air is. The colder the air, the denser it is, and the denser the air, the higher pressure it is. Arctic highs have the highest high pressure of any high pressure systems. That was pretty bad wording, but basically it means that arctic high pressure systems are stronger than temperate or tropical ones, because the air involved with them is colder, and therefore denser. The higher the pressure, the harder it is for lift to occur, and lift is what creates condensation, and condensation creates clouds and precipitation. There were hardly any clouds in the sky today. This is another reason why it is hard to get snow here... when you finally do get cold temperatures, there's no moisture to be found.
But have no fear... clouds will soon reappear.
A low pressure system of moderate strength will drop down from Canada of Wednesday morning. All precipitation will be snow. Earlier we were thinking of more widespread 3-6 inch amounts, but new model guidance suggests a rain shadow over the Seattle area, which would give us amounts of 1-2 inches, while other places could get as much as 6-7 inches. However, a convergence zone may develop in the wake of this low pressure system, which could bring more snow to Seattle. So all in all, it MIGHT balance out. Convergence zones are very tricky to forecast though, so no guarentees. One thing for sure is that the Seattle metropolitan area will be shadowed from snow by the Olympics. Sorry people. We will still get snow though, and 1-2 inches of snow sticking on the roads is MORE than enough to close the schools.
About school closures... this system is coming in Wednesday morning at right about the time of the morning commute. This will make it tough to forecast if schools will close. Whether or not the close Wednesday, I think they will be closed Thursday and Friday. Even though we don't have a lot of snow, the road temperatures are very cold, and any snow that falls will stick to them.
Thursday=residual showers, much like Sunday.
Friday=REALLY cold... highs will struggle to get into the mid 20s as an even stronger arctic high dives down from Canada.
Saturday and Sunday: this is where things get really interesting. Models are all over the place on this one. The GFS model (American) shows a strong low pressure system coming to our north, which would give an initial period of heavy snow and then possibly change it over to rain. The ECMWF (European) shows a weaker low pressure system coming into our south, so we would have less precipitation, but more of it. Giving forecasts for snow would be like finding the needle in the haystack at this point, but the models suggest a snow event perhaps heavier than the one we will have on Wednesday. Heck, if you took an average of the two models, we could see some REALLY heavy snow.
After that, ANOTHER arctic air mass comes through. And snow falls on Christmas! Then another comes through. And another. The models have only been semi-consistent with this pattern, but still, we could be in the cold for a long time. Ice skating on that pond? How bout ice skating on Greenlake? (well probably not that cold)
Stay warm!
Forecast:
Tuesday: 31 19
Wednesday: 31 22
Thursday: 28 26
Friday: 26 18
Saturday: 31 21
Also, just to clear things up, the low temperatures are for the morning of the day. That means there is the morning low, and then the high. For example, the low on Tuesday would be Tuesday morning, not Wednesday morning. Not sure if you knew that, but this is just to clear up all confusion.
December 14, 2008
Predicted: 31 23
Actual: 30 26
The real cold has begun! Friday was cool, Saturday was cold, but today was really cold. And this week is gonna be RAW. This will be the longest, coldest stretch of weaher since 1990. For many of us, that means this will be the coldest Seattle weather we have faced in our life. People are all worried about whether it will snow or not, and I am too, but I'm excited about it being cold too. There is a little pond near my house that frequently freezes. I remember when we had an extended period of cold in 2004 and I could walk on it. I was in 7th heaven then. There's nothing like walking on something you see liquid all the time. I'm expecting to be able to walk on it again this year, and maybe even go ice skating. It's really shallow, so if I fall in, I will be EXTREMELY cold (and actually at a risk for hypothermia since the water will freeze to me after I get out) but I won't drown.
Monday and Tuesday will be frigid but dry and sunny. Nuff said.
Wednesday is where it gets interesting. A low pressure system drops down from the north, and with the cold temperatures in place, all precipitation will fall as snow, except maybe a mix over the coast. We can expect 3-6 inches of sticking snow with this system. It will stick to the roads as well since they are very cold. This storm could close the schools for sure, and Wednesday could very possibly be your last day of school for 2008 if winter break starts next week for you. Not guarenteeing anything of course, and you know how hard snow is to forecast, but at least we won't have to worry about temperatures being on the fringe.
Thursday will be a day of residual snow showers, much like today. Friday will be dry and probably even more cold than tomorrow or Tuesday. Another arctic air mass will dive southward, and this mass will be larger and colder than the one we are into right now. Expect temperatures in the mid to low 20s. Brr!
The weekend, and Sunday in particular, is where things get really interesting. A large Pacific storm will drop from the NW and come in just south of Seattle. This is nearly a perfect track for heavy snow in Seattle. Although the air mass will be warmer and snow isn't as sure of a bet as Wednesday, the snow will be a lot greater in quantity because this Pacific storm will have a lot more moisture than the one expected on Wednesday. Also, since it is coming just south of Seattle, winds here should be from the north, which would keep temperatures from warming too much and in fact just draw down more cold air. I am not saying this forecast is definite at this point, and models have been flip flopping around with it a lot. If the event happened as computer models show it today though, the Seattle area would see heavy snow with totals anywhere from 6-12 inches down to sea level. Cross your fingers, do some snow dances, but don't jinx it. The trick is balance. Appease the Snow God, but don't annoy him.
Forecast:
Monday: 29 20 partly sunny
Tuesday: 29 19 mostly sunny
Wednesday: 30 25 light snow
Thursday: 31 26 snow showers
Friday: 25 16 bitterly cold and sunny
December 13, 2008
Predicted: 36 22
Actual: Too early yet...
The initial storm has passed. Here are some of the peak gust from this storm as of 4 P.M. yesterday. The winds were definitely not over by this point, but this is the only data I could find.
Destruction Island: 95 mph
Forks: 69 mph
Hoquiam: 58 mph
Alki Beach: 52 mph
520 Bridge (Seattle): 51 mph
Oak Harbor: 49 mph
Seattle (Magnolia): 49 mph
Friday Harbor: 47 mph
Shelton: 46 mph
Seattle (Sand Point): 46 mph
Tacoma/McChord AFB: 46 mph
Bremerton: 45 mph
Tacoma/Gig Harbor (Narrows): 45 mph
Seattle (Sea-Tac): 45 mph
Everett: 43 mph
Winds were generally what I expected, except at Destruction Island. Destruction Island is a coastal headland that commonly gets some of the strongest winds in Washington. Almost hitting the triple digits though... that really demonstrates the power of this storm. As I think I said before, the upper level orientation of this storm wasn't favorable for extreme winds in the Puget Sound area, it was much more favorable for the coast and Strait of Juan de Fuca. When a storm is coming in from the SW (like most of our windstorms) a very strong gradient develops on the southern side, and the upper level movement of the storm helps to enhance the winds since the surface and upper-level winds are working with each other. With this storm, the gradient was there, but the upper-level winds were actually coming from the NW. Because of this, the strongest winds in many places occured after the low had passed, something pretty unusual, although not that unheard of, especially for the Strait of Juan de Fuca, which commonly receives strong surges of NW winds after the passage of a low pressure system. Still, it a sub 980 low were to come where it did but come out of the SW, winds in the I-5 corridor would have been MUCH stronger, with gusts as high as 80 mph. Still, the winds here were very impressive, and Lake Washington was quite a sight!
I don't mean to be cocky or anything, but I forecasted this storm better than EVERYBODY else, even the NWS and Cliff Mass. However, there are two things that are different with my situation. First of all, I got lucky. I simply chose to follow the right forecast model. Part of this was from thourough analyzation of satellite pictures, models, and historical situations, but still, I got lucky. Second, places like the NWS HAVE to issue winter storm warnings when there is a remote possibility of significant snow. If the low pressure system tracked further south, places in Western Washington could have seen up to 10 inches of snow. If this occured, I would probably get some eggs thrown at me on school on Monday. Imagine what would happen to the National Weather Service or TV stations.
But the bottom line is, I was right and they were wrong. :)
Now... the cold.
You probably haven't thought of 37 degrees as warm. That was the temperature at Sea-Tac this morning. However, that is probably the warmest it is going to get all week. We have a VERY cold week ahead of us.
Today, we do have a fair shot at getting some snow. An arctic boundry will drop south from Canada, and this could bring trace-3 inch amounts in the Puget Sound area. Forecast models this morning are weaker with this feature than before, but I still think that it will manage to drop some precipitation (probably graupel or snow) before it is all said and done. After this front passes, it will get really cold. Whatever snow there is on the roadways will freeze. Great news for students not wanting to go to school on Monday, and bad news for those trying to get to work.
Sunday, it will be a lot colder and a little drier. There will be some snow showers as a low pressure system to our south destabilizes the atmosphere, allowing for some pop up showers. While these showers will be few and far between, one thing will be certain: they will be in the form of snow. Let's hope a huge one hits the superintendent's house!
Monday-Wednesday next week is the real cold. Highs will be in the 20s, and lows will be in the teens. One feature that the models have been consistent with is a low pressure system dropping down from Canada. If this occurs, precipitation WILL be in the form of snow. For once, it is an easy forecast! We will still have to see if it happens, but if there is moisture then, it WILL fall in the form on snow. No questions asked.
After that low pressure system, another very cold arctic air mass will slide into Western Washington on top of the one we already have.
Long range forecasts suggest that we will be cold for a long time. Some long range models have hinted at HUGE snowfalls in Seattle on the weekend before Christmas. However, if we can't predict snow 6-12 hours in advance, what makes us think a week is like shooting apples in a barrel? Still, it's exciting. Bring on the snow!
Forecast:
Sunday: 31 23 few snow showers
Monday: 27 18 mostly sunny
Tuesday: 24 19 partly sunny
Wednesday: 30 26 snow
Thursday: 29 20 snow showers
December 11, 2008
Predicted: 47 39
Actual: 45 41
Wow! This is probably the most difficult forecast I have ever done. A TON has changed since I wrote last night. Right after I wrote about high winds for the Seattle area, new forecasting models came in and showed a whole new solution... the low coming into the SOUTH of our area. This would just bring us a lightish northerly wind... and increase our chances for snow. A winter storm watch was issued for Western Washington, and a wind advisory was not issued. However, the new model runs of the 00 NAM-MM5 model at the UW show an entirely different scenario: the low coming back up to the north again, and deeper. One way to tell how strong the winds will be is to look at the pressure gradient. A great measure of approximate wind speed is to look at the gradient between Portland. The NAM model shows a pressure gradient of 20 mb! That is huge... the biggest since the December 2006 Hanukah Eve storm. On the other hand, the new GFS model keeps the old scenario, with the low coming in near Hoquiam and weaker. This would give us weaker winds, and a better chance of snow. Personally, I would like higher winds over a increased snow chance, because I don't think that we would get snow in either scenario. The NAM model though... if that were to follow through there would be some very strong winds. One thing of note though... the movement of the storm is not conductive to a strong southerly wind. The storm is dropping in from the northwest, and this means that the upper level orientation of the storm will not match the surface level, and the winds will likely not be as strong. Still... 20 mb is an absolutely ludicrious pressure gradient. A lot will change between now and then, but this new solution just indicates how unique and complex this setup is. The models should be locking on something less than 24 hours out, but they haven't. Whether all hell breaks loose or nothing happens, there will be surprises that weren't forecast. That I can guarentee.
The high winds for the coast and strait are still looking on track. Waves on the coast will approach 30 feet!
Now to the snow... after the front passes, a convergence zone will likely develop in the wake of the low. With the cool and unstable air behind the front, expect snow levels to be dropped to the surface... or lower.
Just kidding... but seriously... this zone could spread heavy snow in a narrow band between Seattle and Everett. The placement of convergence zones is extremely hard to forecast... so the whole central/northern sound area should keep an eye out for snow.
After Friday night, the airmass will turn significantly cooler. Not yet super cold though. Showers will still be around, and these could be in the form of snow or a rain/snow mix. Saturday night, colder air will filter down from the north. Sunday, an arctic front may drop a quick inch of snow or two around the puget sound area. After the front, it could freeze solid. Next week will be extremely cold, with highs as low as the low to mid 20s and lows into the teens. More on all this later. The windstorm is the main focus for me right now, and I have a lot of homework to do as well. Stay tuned. :)
Forecast:
Friday: 42 33 stormy
Saturday: 36 22 snow showers
Sunday: 29 17 few snow showers
Monday: 25 18 sunny
Tuesday: 26 19 sunny
December 10, 2008
Predicted: N/A
Actual: 48 44
Wow! It has been a long time since I have posted. The weather has been SO boring that I have nearly forgotten about this group. But we have a LOT to talk about and a lot of action to occur over the next couple days. First, let's talk about Friday. As of now, there is a developing low pressure in the Gulf of Alaska that is going to drop to the southeast, pretty much right over western washington. There are three things this storm will do... it will bring 1-2 FEET of snow in the mountains above 1-2000 feet, it will bring a lot of wind, and it will usher in a maritime cool airmass, which in turn will usher in an arctic continental airmass.
First, let's talk about wind. I've been watching this system for some time and have been really intruiged by it. Models are switching rapidly but they've been remarkably consistent in general handling this storm. This storm will be driven by a strong jet stream and will represent the boundary between two strongly contrasting air masses. All these things support the cyclogenesis, or "bombing" of this low pressure system. Basically, this means that the low pressure system will intensify rapidly before it makes landfall. On wind, models are saying perhaps 70 knots sustained in isolated spots over the ocean. That's hurricane force. Let me repeat. That is hurricane force. The pressure of this storm, although not that deep (980-985 mb) is very compact. This means that the pressure changes are more pronounced, and there is a tighter gradient. The tighter the gradient, the stronger the winds.
The coast has a high wind watch for sustained winds of 30-50 mph with gusts to 65. There is also a high wind watch for the northern interior, with winds strong but a little lesser, maybe gusts from 50-60.
Nothing has been posted for Puget Sound so far, but there has been talk about maybe posting an advisory. People are forecasting winds of 25-35 mph with gusts to 45. I am going to go ahead and forecast higher winds though, winds 25-40 with gusts up to 55 and perhaps 60. I'm going to do this for three reasons: 1.) the low pressure system is moving very fast, which tends to speed up wind speeds. 2.) the low pressure is coming in very close proximity to Seattle, just a little north, which would put Seattle on the stronger southerly side of the storm. 3.) The flow may produce a mesolow on the lee side of the Olympics, which would speed up winds in Puget Sound and Hood Canal.
A lot can change between now and then, but for Puget Sound, the highest winds are forecast between 4-7 P.M. on Friday. Following the passage of the low pressure, storm force winds are possible over the Straight of Juan de Fuca and northern Puget Sound. These winds will be very strong (50-60 mph gusts) and WILL cause damage. Whether or not Seattle gets winds as strong as I am forecasting, high winds in the Strait are CERTAIN.
Snow: This system is going to bring gobs of snow to the mountains, which is great new, but snow levels will likely be too high for snow in the lowlands. Some snow may mix in, but it will not stick. If it were to snow anywhere, the higher elevation by Hood Canal would be a good bet.
Cold: Cold air will filter in behind the front on Saturday. Saturday will be cool, but not frigid. Highs will struggle to make it into the upper 30s, and with a few random showers about, most would be snow, especially at higher elevation. Saturday night and Sunday, a reinforcing shot of cold air may come in. An arctic front may bring some snow to sea level. Arctic fronts are weak and do not hold much moisture, but they can drop a quick inch of snow, and then freeze it solid in the storm's wake. Remember the Monday Night Football game in 2006? Seahawks vs. Green Bay? That snow fell to an arctic front, and once it passed, the arctic air froze everything solid in the storm's wake. We could see something similar to that, but it's not a sure bet. It's a long ways out. Forecasting models have been trending towards it, though. We will see what happens.
What happens after this?
We get VERY cold and dry. Highs next week will struggle to reach freezing, with lows into the upper teens and low 20s. If you have sensitive plants, protect them. Watch out for your pets too. Interestingly, models keep us cold and dry for a while. It is WAY to early to tell, but some more widespread lowland snow may occur at the end of next week.
Whew!
Stay tuned...
Golly Gee! I almost forgot!
The convergence zone!
The convergence zone could bring SNOW Friday night/Saturday morning in the usual N. King S. Snohomish county areas. The snow could be fairly decent if the zone lasts for a while. Isn't weather so exciting?
Forecast:
Thursday: partly cloudy 47 39
Friday: stormy, mountain snow 41 35
Saturday: cool, rain/snow showers 37 27
Sunday: cold, few snow showers 33 23
Monday: REALLY cold and sunny 30 19
GREAT LINKS:
Scott Sistek's and Cliff Mass's weather blogs. They are chalk full of information. Google them. They are a GREAT resource.
http://www.komonews.com/weather/blog
http://cliffmass.blogspot.com/
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