From Bob Foster. Thanks Bob..
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Hi All,
Just in case you haven’t heard, the National Weather Service has issued a Winter Storm Warning for most of Western Washington. If you are aware of this then disregard.
I am giving meterologists the benefit of the doubt on this one and we’ve planned accordingly.
The expected snow accumulations levels aren’t necessarily the biggest threat region wide, potential for high winds and a significant drop in temperatures today pose larger concerns. Be safe out there.
Bob
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**Winter Storm Warning for Western Washington**
Wednesday, February 23, 2011 – Seattle, WA
KOMONEWS.COM
SEATTLE – After a day of a little snow sprinkled around the region on Tuesday, Mother Nature is reloading for a widespread snowstorm on Wednesday that threatens to drop several inches in spots and snarl the days commute.
*A warning means conditions are imminent.*
A low pressure center moved in overnight and combined with arctic air blasting into the region from the north to make for a widespread snow event across the region, likely the largest snow in the area since the December 2008 storms.
Snow totals on average will range from 2-6 inches, except more along the northern Olympic Peninsula and there could be locally heavier amounts. In addition, strong, damaging winds will blow out of the Fraser River valley through Bellingham into the San Juan Islands that could reach speeds of 60 mph.
Let’s first break it down by time period:
~Tuesday night~
We’ll continue to see random snow showers roaming around the region before midnight. These are not expected to accumulate except for the foothills where you could see 1-3″ as a storm total through midnight.
Then snow showers will increase from the southwest as moisture rotates around an area of low pressure offshore and into the Puget Sound region toward dawn.
~Wednesday morning~
As those snow showers move in, we could see 1-2″ of snow during the morning commute around the greater Puget Sound region. This will still be a slushy snow as temperatures will remain just above freezing, but still has potential to cause traffic issues. Meanwhile, winds in Whatcom County will increase to 30-35 mph in gusts.
You should still be able to get around, especially the main roads, just not very quickly. However, as challenging as the morning might be, the evening is looking far more daunting.
~Wednesday afternoon and evening~
As the low continues to spin moisture our way from offshore, winds will increase out of the Fraser River Valley to 50-60 mph in gusts. This will be akin to an icy blow dryer that will blast arctic air into the region from the north.
The cold north winds will then collide with the southwesterly winds over Western Washington and make for an enhanced area of convergence — think of it as a super convergence zone. Models right now indicate this battle will brew over Snohomish County making for very heavy bands of snow and likely limited visibilities.
That band of snow will gradually move south through Seattle late Wednesday afternoon and evening as the low pulls off to the south and the north wind pushes along. Thus even the metro area could see a burst of heavy snow during the afternoon and evening commutes. Outside this battle, there will be roaming heavy snow showers as the air becomes unstable and thus we could see some thundersnow-showers as well. And any kind of thundersnow would likely have very heavy snow and gusty winds — again making for poor visibility.
The convergence zone will continue to slide south and behind it will roll in the arctic air, dropping temperatures into the 20s. Thus, a flash freeze akin to what occurred on November 22 is possible and drivers really need to prepare for treacherous conditions. Meanwhile, moisture wrapping back around the low pressure center could roll over the top of this arctic air continuing the snow at times through Wednesday night on to icy roads.
Bottom line, travel around the Puget Sound lowlands will likely be treacherous from early afternoon Wednesday through the night.
Also, freezing spray is an issue up around the San Juans and Whatcom County.
~Wednesday night ~
Snow showers will linger over most of the area, save for the far north, with steady, heavy snows now shifting into southwestern Washington. Could see another 1-2″ on top of whatever already fell. Lows will be down into the 20s, especially north of that convergence zone, so beware of icy roads.
~Thursday~
Snow showers likely to continue into Thursday morning, especially south as the battle between the north and south winds moves south. We’ll clear from the north but stay quite chilly with highs only in the low 30s.
~Thursday night through Saturday~
The snow is done, and now it’s just cold. We’ll be mostly clear Thursday night with lows in the teens to low 20s. Highs Friday under sunshine will struggle to get to freezing. Lows Friday night again will be in the teens to low 20s.
Saturday we start to moderate a little to the mid 30s under partly sunny skies.
Long range models indicate we might be playing the snow guessing game again on Sunday, but we’ll have to see how cold we get after Wednesday’s events.
Snow breakdown by region:
Whatcom County/San Juan: 1-3″, mainly windy is the event there
Clallam: 5-12″
*Skagit/Snohomish: 4-8″
*King/Pierce/Kitsap: 2-6″
Thurston/Mason: 2-5″
Coast: 2-5″
Southwestern Washington: 2-5″
Quick Recap:
* Snow showers continue to roam in Tuesday night. Could see 1-3″ of slushy accumulations late Tuesday night from Seattle area south and west to coast.
* Snow showers increase Wednesday in heavy snow bands. Temps still in mid 30s. Morning commute could be affected.
* Heavy band of snow sets up in North Sound on Wednesday morning, slowly moving south through the afternoon and night.
* Wednesday evening commute could feature heavy snow and/or freezing temperatures with flash freeze on roads a la Nov. 22 possible.
* Snow on northern Olympic Peninsula could be greater than 6″ Wednesday.
* Strong winds blow out of Fraser River Valley gusting to 50-60 mph in Whatcom and San Juan counties.
* Freezing spray an issue to mariners around San Juans and waters off Whatcom County.
* Temperatures to drop below freezing late Wednesday into Wednesday night
* Very cold temperatures expected late Thursday night into Saturday.
* Heavy snow continues in mountain passes.