Thursday, February 23, 2012

Lowland Snow Showers, Cold Air, and Strong Winds

 Extra:  If you would like to listen to my discussion of this weekend's weather on KPLU, check out:
http://www.kplu.org/post/snow-looking-likely-sunday-only-dusting-most

A lot of action coming up, including a good chance that some lowland folks will spot a few snowflakes. (Note to TV stations:  no big lowland snowstorms!!)

A strong Pacific front is approaching us now, behind which there is some cold air.   Here is the forecast for tomorrow afternoon of sea level pressure, near surface winds, and lower atmosphere temperatures---you can see a very nice windshift with the front.


This pattern will produce strong SE winds over NW Washington--something that often happens BEFORE the front passes through.

As the front moves through, not only does cold air follow (blues and whites), but an intense pressure gradient develops over the region. 


 The result will be a strong westerly surge through the Strait with sustained winds of 40 kts with higher gusts.   These winds are headed toward Everett and Mukilteo---yes, my favorite seafood restaurant...Ivar's Mukilteo Landing..is in the cross hairs.  THIS TIME THEY BETTER SCREW DOWN THE LATCH ON THAT HATCH! 

A convergence zone will then set up, but at this point the air is still a bit warm for surface snow....except if the zone really revs up and pushes the snow level to the surface.  Lots of snow in the mountains of course.   But then its get interesting...or I should say MORE interesting.  The models are taking a second trough southward over us and a surface low follows (see figures)



 This is getting awfully close to the canonical snow pattern and in fact the models are indicating some light lowland snow in places (see graphic of 24 h snow ending 4 PM Sunday).  NE flow will also push out of the Fraser on Sunday...so Bellingham will get quite cold.

We don't have much skill in getting the exact distributions of the snow in such a case and the temperatures are a bit marginal.  Considerable uncertainty in distribution and amounts over the lowlands.  But some of you will see the white stuff at or near sea level.  And protect delicate plants and animals on Monday morning...it will be chilly.

5 comments:

Joshua said...

Great blog entry, Cliff. Excited to see what happens (if much of anything) with this snow event!

On another note, I really think you should additionally start a separate blog, titled something like "The Current Conditions at Ivar's Mukilteo Landing" :)

Cliff Mass Weather Blog said...

I want to assure everyone that I am not on a retainer of fish and chips or clam chowder from a certain seafood chain...cliff

Stormwolf said...

Cool entry! I like your blog :) you have one of the best interesting weather information in a blog Ive seen for a while lol

Do you mind doing an article comparing the weather pattern differences between the pacific northwest and here in Calgary AB where I am? that would be quite interesting to read :)

--
Stormwolf
http://scientific-madness.blogspot.com/

Dana G said...

Would you consider it crazy to overnight on a boat in a slip at the Everett Marina this Saturday night? Or just ... interesting? We do want to get more used to "weather" as when we set sail, we will not always have the option to be fair weather sailors.

Unknown said...

We have just about 3" of snow in Woodinville (elev ~510) as 0940 25 feb. Must be convergence zone?