August 27, 2009
So, today I'll talk about our early autumn storms and our very tricky extended forecast. First of all, as most of you know, the tropics are very active in the months of august and september, since the warm water temperatures allow hurricanes and to develop. In October, when the northern regions have cooled significantly but the tropics are still warm, there is a large difference in temperature to support the development of extremely strong extratropical storms. Deep, tropical moisture is often entrained in low pressure systems at this time, and the differences in air temperature across the latitudes give the storm more fuel and make it stronger. The earliest major windstorm to hit the northwest, the Columbus Day Storm of 1962, was also the strongest, with gusts estimated at 195 mph at Cape Blanco, a headland on the Oregon Coast. I know this was a brief and maybe confusing explanation but frankly I just subjugated myself to an extremely intense workout and I can't really think straight right now.
The extended looks very complex. A "cut off" low pressure system (a low pressure system that stalls because it has been "cut off" from the jet stream) will heavily influence our weather over the next couple days. The models have been flip flopping a little, as these lows tend to have a mind of their own, but after a weakening system comes ashore Friday (rain will mainly stick to the coast) we will return to a pleasant late summer pattern with highs in the mid 70s and partly cloudy skies. I will be out of town Friday through Sunday to go tuna fishing. Wish me luck!
Thanks for reading,
August 25, 2009
Hey guys. Again, not too much new stuff to talk about. I don't know if any of you guys noticed, but there was a fairly decent marine push last night as a weak system came onshore. It opened all the doors in my house and kept me awake for a while (it was pretty loud).
Anyway, I am leaving to go tuna fishing Thursday night and I will be back late Sunday. Wish me luck! I'll have a more in-depth analysis of what to expect tomorrow, as well as some notes on what generally happens to the atmosphere when we begin the transition from summer to fall, and maybe talk about the rare but extremely powerful storms we occasionally see in early autumn.
August 24, 2009
Hey everybody. The forecast hasn't changed one bit, so I'm not going to make one right now. I hope you can understand.
Also, if you have any feedback for my blog or things you would like to see, post your ideas on the wall. It's always good to hear how this thing is working and what people want from it.
August 23, 2009
Ok, so this is the third time I've tried to write this forecast... I'm kinda sick of trying... so I'll do an update later today. My computer keeps crashing and spazzing out. Actually, what the heck I'll just do it right now and hope my computer doesn't repeat history. Anyway, there isn't really much new to talk about today as far as the short range forecast is concerned, but I thought I'd talk about El Nino and La Nina since we will be under the influence of El Nino this coming winter. El Nino and La Nina are both part of the El Nino Southern Oscilliation (ENSO) pattern in the eastern tropical Pacific ocean. This oscilliation, or switching, refers to the temperture of the water in that region. In a La Nina phase, the water temperatures are cooler than normal, and in an El Nino phase, the water temperatures are warmer than normal. This is because in a La Nina phase, there is more upwelling in the eastern tropical Pacific, which brings cool, nutrient rich water up from the depths to the surface, and in an El Nino phase, there is decreased upwelling, so the water is more sterile and warmer. El Nino and La Nina both have different effects around the world, but since there are so many, I'm just going to talk about their effects in our location, the Pacific Northwest. Generally, El Nino will make us warmer and drier, while La Nina will make us cooler and wetter. Unfortunately for skiers, it looks like this year will be an El Nino year, with warmer and drier conditions prevailing during the winter. Still, we live in the Pacific Northwest, so we should get a good amount of snow anyway. And if there is no snow here this year, you can always head south to California during an El Nino year because the storm track is centered over them in El Nino years as opposed to us. In a La Nina year, the mountains get tons of snow because we are both wetter and cooler than normal. Especially in La Nina years, upper-level trofts from the Gulf of Alaska slide down south and direct cool and unstable air into our state. The Seattle metropolitan area usually is shadowed by these events, but the Cascades, who are perpendicular to this flow, commonly pick up foot after foot of snow. That is what happened during the 2007-2008 ski season, when Alpental, my local ski area, picked up 50 feet of snow. One interesting thing about El Nino and La Nina is that we generally do not have windstorms on these years. However, we can still get "Pineapple Express" flood events with El Nino and La Nina years.
Here's a great website to check out the tropical Pacific and see what it is doing. http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_update/sstanim.shtml
August 22, 2009
So I was out of town yesterday and most of today, but since I'm still back before the day is out, I thought I might entertain my friends and apprentices alike with another entry on my blog. The forecast looks pretty much the same; morning clouds and afternoon sunshine will abound. A few showers will occur Tuesday and Friday as decaying fronts, weakened by high pressure stationed over the eastern Pacific, clip our area. The extended forecast brings us warmer conditions for next weekend!
August 21, 2009
Probably my favorite summertime weather (besides thunderstorms of course) is when we get a huge marine push after a hot spell. There's nothing I like more that sweltering in heat one day, leaving all the doors and windows open, and going to sleep with a cool refreshing breeze permeating throughout the house. Then when you wake up in the morning, you are shivering! There's no severe weather or tons of rain involved, but there is something to be said about a refreshing marine push after a stretch of hot weather. It's almost like going through microsoft word and getting all the typos out of your paper, or completely cleaning and reorganizing your room. It's like somebody just swept away everything and replaced it with something new. And although I love hot weather where you can go down to the beach or go fishing, I love it even more when everything is blown away and all you are left with are cloudy skies and cool temperatures. There is something really refreshing about that.
Anyway, these marine push events can only really occur when there is a heat wave to begin with. Our thermal troft- an area of low pressure west of us that draws in dry and hot air from the east- eventually shifts west because the predominant flow of the atmosphere in our latitudes is westerly. When this happens and the low is in eastern Washington, it now pulls in air from the west, which is cool and moist. That's why we are so cloudy and cool today; the thermal troft has passed to our east and is now drawing in cool air from the west, which we are under the influence of.
We should warm up a couple degrees this week, as highs will struggle to reach 70 today but should be in the mid 70s by next Friday, although there is a slight chance of rain for next weekend, which is our annual tuna fishing trip. Stay tuned...
August 20, 2009
There isn't really much new to report today. The convection that I speaked of a couple days ago possibly developing on the east side of the Cascades doesn't look like it is going to happen because there is not enough moisture. We will see a full-blown marine push event tonight, and tomorrow will look nothing like yesterday or today. I will be out of town starting tomorrow and I'm not sure exactly when I will get back but I'll be back by Sunday at the latest.
August 19, 2009
You always know how the media tends to hype up certain weather events, especially snow ones? Well as I read Cliff Mass' weather blog this morning, he brought to my attention that they hype up nearly every type of event, including heat waves. Let's examine the bias.
Jeff Renner is a very knowledgable forecaster, and I think he was a student of Professor Mass. Still, King5 News (In Mass' opinion the station that tends to hype things up the most) sent Jeff Renner out there with the goal to not provide a totally accurate forecast but to scare the public to get their attention (and therefore get more people to watch King5 News for "the latest" on the situation. Jeff Renner quoted the high temperature for Vancouver, Washington because it will be one of the hottest areas in the state today since it gets the Willamette Valley heat. And maybe Jeff Renner went on to explain that we, up by Puget Sound, won't be as hot because we are under more of a marine influence since we are right next to Puget Sound. Still, that's not what is going to stick in people's minds. Many people are going to subconsciously equate the Willamette Valley heat to what they can expect in Seattle. And to make matters worse, they have some extremely scary on-scene reporters. Like Jim Foreman. Check out the Cliff Mass Weather Blog @ http://cliffmass.blogspot.com/ . I have to say, the reason why Professor Mass is such a good professor is because he mixes extensive knowledge with charm and a great sense of humor and that he absolutely loves weather and does tons of things for the community to educate them even if it doesn't translate into any gain for him. He's just happy to share his passion, which I think is great.
The story remains the same... we will top out at about 90 degrees today and will begin cooling down Thursday. Friday, it will really be noticeable, as models predict that we won't break out of stratus clouds the entire day. Thursday will be 7-10 degrees cooler than today, and Friday will be nearly 20. For the rest of the extended forecast, we will be in a more typical summer pattern, with highs in the mid 70s and clouds in the morning burning off into clear skies in the afternoon or early evening.
August 18, 2009
Today and the next few days will be absolutely beautiful. High pressure is over the region, and a thermal troft will develop over the coast, which will allow Seattle to be under the influence of dry and hot offshore flow off the Cascades. The good news is that this heat wave will be shorter, cooler, and much drier than our last one in late July into early August. Beginning Thursday, the offshore flow will switch to onshore, and by Friday, we will be back to normal, with highs in the mid 70s. This is a typical "marine push" event, in which the thermal troft shifts eastward, ushering in cooler oceanic air off the Pacific. Wednesday will be the warmest day, and we will likely reach 90 for the 8th time this year. The record, 9, was set back in 1958.
There is a slight risk of isolated thunderstorms Thursday east of the Cascade crest, and I also see some convection on the radar, where heavy showers are occuring on the north side of Mt. Rainier.
On an interesting note, some of the models at the UW Atmospheric sciences website show more vigorous low pressure systems developing. They are going to mainly go north, but still, this is a sign that fall is just around the corner. Go to http://www.atmos.washington.edu/~ovens/loops/wxloop.cgi?mm5d1_x_pcp3+%2F%2F%2F3 to see what I was looking at. The more active pattern can be seen in frames 40-60.
Have a great rest of the summer,
August something, 2009 (welcome to summer... I think it's in the mid teens)
Hey everybody. I thought I'd give an update since I haven't looked here for quite a while. I've been all over the Pacific Northwest lately and only been home for a couple days for the past month. I actually just got back from Portland, where I saw my uncle and some friends. I had a great time, but duty calls. Let's talk meteorology!
Ok, so the past month or so the weather has been rather cool. Since the heat wave died, we've been under a westerly flow, and cool air off the pacific has flooded into the region, giving us highs in the 70s and even only in the 60s some days. For the sun and heat lovers, I have some good news, though. We are going to see a much more traditional (as opposed to the last one) heat wave in the area. A thermal troft will develop offshore, which will turn the flow in our area from westerly to easterly. Now, instead of cool air coming off the ocean, you will have warmer continental air. To add to that, when the air slopes off the Cascades, it warms and dries as it is compressed (it is compressed since the pressure at sea level is higher than it is at places of elevation). That will give us clear skies and warm temperatures topping out at the lower 90s in the Puget Sound lowlands later this week, with Wednesday being the hottest day. After that, we will cool down a little, and expect some showers by next weekend.
Enjoy the rest of your summer,