Storm on the Way

Thursday, April 1, 2010

4:05 P.M.

Hey everybody. The storm is on it's way. We have a lot to look at. The four frames above show the development of the low pressure system according to the NAM model in three hour frames from 2 A.M. Friday to 11 A.M. Friday. First, though, let's look at a current water vapor satellite image. This image shows the temperature of the tops of the atmosphere, and the colder the water vapor, the higher the cloud tops, and generally, the stronger the storm and heavier the precipitation.

Can you see the bent-back occlusion starting to develop? Also, there is the dry slot which is becoming more well formed by the hour. It is that dark spot to the west of the cloud shield associated with the storm. These are the trademark signs of cyclogenesis - the intense development of a mid-latitude cyclone.

The models that came in earlier this morning were similar to those that came in last night except that they had further diverged. The GFS was even weaker and further south and the NAM was even stronger and was further north. Based on the satellite image I see now, I'm going to go with the NAM. I have to be cautious and exercise restraint but I still believe that the NAM is the superior model in this situation. I predict the actual storm to be a combination of the two models - meaning it will have a central pressure of 975-980 millibars and will come ashore southern Vancouver Island.

The winds will be strongest on the coast. Places on the exposed beaches could have winds of 80 mph and coastal headlands could have isolated gusts to 100. That's extremely powerful. The same is true for the mountains, as mountain ridgetops could have some very strong winds as well. A high wind warning is in effect for the coast as well as the northern and southwestern interiors for gusts up to 60.

We are still not sure if Seattle will get winds reaching high wind criteria because of the uncertainty of the track of the low. Based on the cyclogenesis I see occuring, I'm predicting a marginal high wind event, with top gusts in our area ranging from 50 to perhaps 60 miles per hour. Let's hope that we witness this. Or, well, at least I hope we do. :)

This shows the predicted 24 hour snowfall charts for Friday ending at 5 A.M. (less than 24 hours - from the initiation of the model on, which was probably around 7 A.M. - I could be wrong). The second frame shows the snow expected from Friday 5 A.M. to Saturday 5 A.M. A winter storm warning is in effect for the Cascades for 1-3 feet of snow from this storm with locally higher amounts. Travel through the passes will be dangerous with heavy snow and blizzard conditions at times.

The lowlands will see an inch or so of rain with this event. Places like Sequim and slightly west of it will be heavily rainshadowed by a southwesterly flow.

I'm gonna be flying a huge kite and shooting some video on a very well-exposed beach on Whidbey Island. Have fun and enjoy this storm!

Charlie

Weak storm coming

Thursday, April 1, 2010

12:05 A.M.

So there's a weak storm coming in later today. Not much to talk about.

APRIL FOOLS!!!

The strongest storm of the year looks to come in later today and especially on Friday. So strong in fact, that I've cancelled my prospective visit to UBC to check it out. Models are in disagreement right now among the exact details, but they are in general agreement that we will get a strong storm. The GFS model, which is usually a little more accurate, is the weaker of the two. This frame of it shows the expected winds at 5 A.M. Friday and shows the strong 988 low pressure center off the coast. Peak winds in our area will probably occur around noon after the low deepens to 984 millibars at Tatoosh Island and heads into southern British Columbia. That scenario would give high winds to the coast and north interior wind wind advisory level winds (gusts up to 58 in isolated spots) in the Puget Sound area. What really caught my eye, however, is the NAM model.

This model shows a developing 984 mb low off of our coast, which will then mature to 980 millibars as it heads into Barkley Sound off southern Vancouver Island. This, I believe, could bring high winds to the lowlands, and it is something we will have to watch for. If this scenario came true, I predict we could see some damaging winds in the lowlands and some power outages. Get ready!

Another aspect of this storm will be the precipitation associated with it. Precipitation totals could be around an inch in the lowlands from this storm and nearly 4 inches in some places in the mountains. Much of that will fall as snow, meaning some places could see as much as 40 inches from this one storm! This above image, taken from the NAM model, not only shows the precipitation field associated with the storm but shows the bent-back occlusion, the trademark of a strong storm.

And, of course, there is the snow. This chart shows the 24 hour snowfall from 5 A.M. Friday to 5 A.M. Saturday. They are monstrous! Widespread amounts of 1 to 2 feet are found in the Cascades. Add that to the additional foot the day preceding and day following and you are talking about 3-4 feet of snow from this one storm in the mountains. These is very unusual for April. I hope it keeps up though! And models do show a weaker, cool storm settling in early next week for some more snow in the mountains. :)

Enjoy what may be the strongest storm for some while!

Charlie

Another Big Storm and Tons of Snow in the Mountains

Sunday, March 28, 2010

9:23 P.M.

Hey all, I'm sorry I haven't updated in so long. Junior year man... if you are an underclassman, get ready for it. It's intense. And the fact that I want to be successful in life is what is keeping me bogged down with work and causing me stress. I think that's a bit messed up... schools assign way too much work. They are basically discouraging successful individuals from continuing from assigning so much work. They say they are preparing them for the workplace but my parents don't stay up till 12 each night doing homework. I think it's a bit rediculous. But anyways, I'm on spring break now and can finally talk. And a big storm is coming right on tap!

Ok so I fell asleep before I could finish this, so that's the storm we saw. My bad....

Anyways, let's get to the snow, something I am very excited about. Following this storm, we will be in a post-frontal cool showery regime, which will bring tons of snow to the mountains. A winter storm warning is in effect for 18-30 inches of snow above 3000 feet. That's the most snow we've seen from a single storm all year long. And it's spring! Now that El Nino is gone we are finally seeing some glimpses of what a normal Pacific Northwest winter is like. You can see the cold cumulus clouds on the visible satellite image, and that is what we will be under the influence of today and for much of next week. Lightning strikes have already been recorded off the coast and we may see some thundershowers here today. Also, don't be surprised if you see some snow flurries in the mornings this week! Nothing will stick, it may catch you by surprise.

This picture shows the predicted snow totals from 5 A.M. Monday to 5 A.M. Tuesday, and as you can see there are widespread amounts of snow totals of one foot or greater. The snow will continue throughout the week with amounts of 6 to 12 inches occuring each day. Winter is back!

Charlie

お！ そうですね！ (O! Soodesune!)

Friday, March 5, 2010

11:16 P.M.

The expression above is one in Japanese that expresses surprisement or amazement. It's basically the translation of "wow!" Why do I say "wow?" Well, take a look at one of the forecasted storms for later next week, shown at the top. That frame shows the estimated three hour precipitation rates ending at 1o:oo P.M. Wednesday. As you can see, there is a broad swath of moderate to heavy rain, and the storm will actually still be intensifying at that time. It will also have a steep pressure gradient and even though it looks to head off into the Queen Charlottes or northern Vancouver Island it could go further south. Those hoping for a storm like the one forecasted should not get their hopes up, though, as most forecasts with storms like that haven't come true so far this season for some reason for another, probably because the El Nino conditions have some effect on the models. In any event, I'm excited to see what happens.

As this satellite image shows, we are under a ridge of high pressure with a front dropping down from the Gulf of Alaska. This front will come through Sunday, and bring rain with it. Another front will come Tuesday, and in between these fronts rain showers will be seen in the lowlands with orographic snow showers in the mountains. Highs will range from near 60 tomorrow to the lower 50s Sunday to perhaps the lower 40s Monday! Then, they will gradually rise up to the lower 50s/ upper 40s.

I am going to the annual 2010 Pacific Northwest Weather Workshop tomorrow! I'll let you know how it goes.

Charlie

Wednesday, March 3, 2010
9:50 P.M.

Hey everybody! So I have some absolutely fantastic news for skiers and snowboarders! For the first time in a really, REALLY long time, it looks as though we could get into a snowier pattern for the Cascades. Why are we going to see snow later on there as opposed to other times? The answer is all in the jet stream. Take a look at this picture of the jet stream. The jet stream is the "highway" for the storms; they ride from west to east along it. The reason why we have had a fairly mild winter is because the jet stream has been splitting right around us as a result of high pressure centered off of our coast.

This is an example of the split flow pattern that we have seen so regularly this year and is the forecasted atmospheric conditions for 00 UTC Sunday. Since there is a split flow at that time, there will not be cool conditions. The cool pattern will resume when the jet stream looks more like this. This graph shows the 06 UTC Wednesday atmospheric conditions.


See the difference? The latter one has the jet stream entering from a much higher latitude - the Gulf of Alaska as opposed to off the Oregon/Californian coasts. Also, there is no split in the jet stream over us. There is one in the picture though. Can you identify it? It is way down south.
Let's take a look at the weather conditions forecasted. From now on to Sunday, where a jet stream similar to the first picture is in place, warm and dry conditions will be in place over the region. However, from Monday on, we will be under the influence of the jet stream from the Gulf of Alaska, bringing us cool and showery conditions.

Our first shot at precipitation will come later Sunday but our first shot at mountain snow will come after that as we are under the influence of post frontal showers. Here is a picture of another system early Wednesday morning (1 A.M.). You can clearly see the main front pushing through, and by then, it should be cold enough that even the main front will have snow in the passes with levels possibly as low as 1500 feet. See the showers behind the front? Those will fill into the area later and cause snow in the mountains and showers down here. With strong sun angles and an unstable atmosphere I wouldn't be surprised if some of these showers grew quite strong or had some ice pellets. We'll see.
Peace and love,
Charlie