Saturday, November 29, 2014

Arctic Blast Hits Washington State

With the passage of what local meteorologists call a Modified Arctic Front, our region has been hit with plummeting temperatures, low humidities, and very strong northerly winds, with some locations experiencing gusts over 50 mph.   Over 30,000 customers have lost power from the winds and snow is falling on the northern side of the Olympics.

The Arctic front was associated with large pressure gradients between the interior of British Columbia and Washington State, results intense wind acceleration in the Fraser River and Okanogan River gaps. (see NWS pressure/frontal analysis and UW WRF temperature/pressure forecast for 10 AM Saturday)

The max gusts (mph) for a subset of western WA stations is shown below:  strong winds (gusting to 40-60 mph pushed out the Fraser Valley across Bellingham to Blaine and  accelerated over the water. Some pushed into the Strait and other strong winds headed southward into Puget Sound.  Can you imagine if there had been a big coal pile north of Bellingham at the proposed Cherry Point site?   The dust plume would have spread to the southwest toward the San Juans....

 In eastern Washington, even stronger winds extended southward out of the Okanagan and pushed to Oregon along the eastern slopes of the Cascades.   Rattlesnake Mountain above the Tri-Cities had a max gust of 96 mph!

Winds along Puget Sound and Lake Washington have been vicious, with white caps galore.

If you want to experience, the power of the current winds check out this wonderful high-def video by the areas leading weather-cam enthusiastic, Greg Johnson of Skunk Bay Weather (click on image or link)

I was just a Magnuson was amazing out there, with big waves and white caps...and an excellent rescue of a boater by a Coast Guard helicopter and a Seattle Police boat.  As I write this, large branches are falling off evergreen trees in back of my house.  Northerly winds over Puget Sound at West Point (see below) hit 41 knots (47 mph)...which is a VERY strong wind speed from the north. I have heard of substantial erosion on the north side of the Kitsap at Hansville and on northern Bainbridge Is.

 But the strongest winds are now over and we can expect things to settle down this afternoon.  The pressure difference between Bellinghan (BLI) and Kamloops, BC has dropped considered from its peak of 15.22 hPa (8.4 hPa and hour ago)

Northerly winds tend to cause more branches to be lost than southerly winds at the same speed, since trees are far more accustomed to strong southerlies in our area.

The upslope flow has ended between Sequim and Port Angeles, where 2-6 inches fell (see cam for a location between Sequim and Port Angeles):

There will be no precipitation the next two days, with temperatures falling into the mid to lower 20s in western Washington.


David B. said...

Easily the strongest winds so far this season here on Bainbridge Island. Lots of downed trees and power outages. NWS should have at least issued a wind advisory for areas near Puget Sound.

Katie G said...

Ditto the Bainbridge Island comments. Interesting nothing reported about most incredible wave action seen in 40+ years right at high tide (12.2) yesterday (must have been low pressure as well for those facing North (Skiff Point). Extremely large debris tossed like tooth picks (Ocean storm style). Comments were at early am water was exceptionally calm and within minutes went to most violent water seen. Flooding from sound today 1/10th what it was yesterday....

Rod said...

Thanks, Cliff,

Heckuva forecast. You folks nailed it, again.

I always appreciate your take on the weather.


Jeff said...

Oh, glad to hear the rescue of the boater was successful! We took the dogs to the off-leash area and my older one, a sheltie who must have been an anti-aircraft gunner in a previous life, was going berserk barking at the coast guard chopper as it went back and forth.

Winds are always so much stronger out at Magnuson, but I was still surprised by the gusts. We steered clear of overhanging trees.

oscar said...

Cliff -
what is it that brings us this type of weather year after year around thanksgiving? Is there some phase change or consistent alteration in the jet stream that seems to occur around this time? The reliability of a cold blast peri-turkey day seems to defy randomness - enlighten us bloggees, if possible...

Harrison said...

Cliff...This seems non-El Nino like. It seems like El Nino is not playing according to its scheme. Here in KCMO we've had NO snow. Woodinville, Washington, my hometown has had more snow 0.8 inches than here in Kansas City proper 0.0 in. What's going on here? PDO stronger?

Sulla said...

The forecasters were asking for it as soon as they went warm and dry for this winter, which they began harping on what...last July? ;)

Much has been made of El Nino, but really, how many times have we gone THREE winters in a row and lost out on the snow lottery? Even back-to-back low snow winters are not that common (which is what we had the last few winters). That's been pointed out on this blog before, but it would be nice to see it revisited now.

Snowiest November in 4 years...check. We have a solid 10 more weeks to get more.

clive boulton said...

Arctic blast apparently pushed the pineapple express down to Northern California (great except for my heating bill).