January 05, 2019

Major Wind Event For Western Oregon and Washington

3 PM update at bottom

A major wind event is now probable for western Oregon and Washington, potentially the strongest windstorm so far this winter.

Very strong winds, with gusts to 50-80 mph, will move up the Oregon coast this evening and then pummel western WA in the morning hours, ending with a powerful surge of westerly winds in the Strait.

This is serious, so I would be prepared (batteries, don't drive around during strong winds, etc.).  There will be power outages.

The 8 AM GOES-17 weather satellite imagery shows the storm west of northern CA and southern Oregon (you can see the swirl of the clouds).

And the sea level pressure forecast for 10AM this morning suggests an elongated area of low pressure associated with the storm, with an area of very large pressure change (gradient) to its south. THAT is where the strong winds will be.


By 10 PM tonight, the area of large pressure change moves along the northern Oregon Coast, bringing very strong winds from Seaside down to North Bend.


Three hours later (1 AM Sunday) the hyper pressure gradient reaches southwest Washington.


And by 4 AM has pushed over Northwest Washington, including Puget Sound.


I will now show you the output of the UW high-resolution ensemble system, probably the best regional ensemble system in the U.S. (this is the kind of system I have been trying to convince the National Weather Service to do nationally).   The graphic is from the Seattle WindWatch website, by the way (and was create by UW Research Meteorologist Jeff Baars).

This graphic shows the maximum wind gust forecast over Seattle from a large number of high-resolution forecast runs.    Wow.  I am charging my smartphone immediately!  Nearly all of the forecasts are going for a significant event (gusts over 40 mph) and several have gusts over 50 mph! The timing of the peak winds vary a bit (between roughly 1 and 7 AM).
Now let me give you a more spatial view, showing the 4-km resolution WRF run made at the UW this morning. 

At 10 PM tonight (Saturday), really strong winds (blue and brown colors) are hitting the northern Oregon coast (up to 65 knots, about 75 mph!)



By 1 AM, the WA coast is being savaged by 50+ knot gusts, and strong winds are just reaching Olympia.


One hour later, Puget Sound is in the crosshairs of mother nature, with up to 60 kt gusts reaching south Seattle.   Big winds continue on the coast.


At 4AM, winds have decreased slightly over Puget Sound, but an extraordinarily strong westerly wind surge has pushed into the eastern Strait of Juan de Fuca, northern Whidbey Island, and the southern San Juans.   We are talking about 60 knot gusts.


In short, it is highly probable that this will be a major wind event.  Perhaps not the equal of the truly historic storms (eg., Chanukah Eve and Inauguration Day Storms), but quite possibly the big wind event of the winter.   The only thing that will help mitigate the power outages is the pruning by previous wind events.  But I expect that tens of thousands will lose power over the region.

Now back to charging all my electronic gear.
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Major New Prediction Tool

UW Research Meteorologist Jeff Baars has developed an exciting new forecasting too, one that digests and then plots new forecasts made EVERY HOUR by the NOAA/NWS HRRR model (HRRR stands for high-resolution rapid refresh).  This approach is also called a lagged ensemble.  Observed is in black.  The HRRR model simulations are consistently going for a big event here in Seattle, with some location in Seattle experiencing winds above 50 mph.   Think of this as a temporal consistency check in the forecast.  Also note that the big. winds don't last long...an hour or so.  Nothing much until midnight.  Then things go bad rapidly.



January 03, 2019

Forget El Nino, StormFest is about to Hit the West Coast

Things often calm down after January 1 during El Nino years....but not this year...with the U.S. West Coast from central California to Washington State about to be pummeled by a series of storms.   Rain, snow, wind?  Plenty for everyone.

A view of the latest infrared satellite imagery shows an amazing line-up of one storm after another stretching way into the Pacific.  A traffic jam of storms.


Let's examine our stormy future, using a series of sea level pressure forecasts from the UW WRF weather forecast models (solid lines are sea level pressure, shading in lower atmosphere temperature).

At 10 PM today, a  strong low is just off the northern tip of Vancouver Island.


10AM Saturday brings an energetic low center into northern CA.


10 PM Sunday?   Another storm hits central Oregon!  And another system is in the wings.


That storm is right off our coast late Wednesday.

 
El Nino late winters generally have less action---not so this year!   

What about precipitation you ask?   Do you really want to know?  The accumulated total through 4 AM next Thursday is impressive, with 5-10 inches over many mountain areas and even 10-20 inches over parts of northern CA, the Olympics and southern BC.


Snow?   There will be abundant amounts.   For example, here is the accumulated snowfall for the 72 hours ending 4 PM Wednesday.  2-3 feet for the high terrain from the central Sierra Nevada to southern BC.  Our winter ski season is secure.


Wind?  You bet.  Each of these storms will bring strong, damaging winds to a favored area of the coastal zone and mountain peaks.  

There is a silver lining of all this action of course:  it will provide an immense amount of water to fill our reservoirs and enhance our snowpack, a snowpack that is now in pretty decent shape (see latest summary below).  Water resources should be fine next summer.

But all these facts on the ground and favorable forecasts don't stop some of Seattle's wacky local media from talking about drought for our region, with the Seattle Stranger being one of the worst (see below).  Facts should matter---apparently not at the Stranger.




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