Snow showers dot region Tuesday with more for Wednesday

SEATTLE -- Tuesday brought more new snow to parts of Western Washington while others stood on the sidelines awaiting their snow turn for Wednesday.

Schools throughout Western Washington were delayed or closed on Tuesday due to snow and ice on area roads, and road crews were busy dealing with spinouts as they tried clear snow from highways.

In the mountains, so much snow is falling that The Washington Transportation Department closed Interstate 90 across Snoqualmie Pass for five hours for avalanche control work.

Snow showers will continue in some areas through Tuesday, and a Puget Sound Convergence Zone was starting to bring some steady snow to Snohomish County, but the Seattle metro area, south King County and the Kitsap Peninsula has been somewhat protected by shadowing effects of the Olympic Mountains and some milder air that even brought some rainfall and that shadowing will continue through Tuesday, meaning the Downtown Seattle core to Sea-Tac Airport will likely remain bare during the day.

Outside the shadow, snow showers will continue with 1-3" possible in snow showers, and perhaps greater amounts in the convergence zone areas of Snohomish County.

Snow amounts from Wednesday to storm vary, geographically

In the meantime, a powerful Pacific storm continues to wind up and head our way for early Wednesday morning and a Winter Storm Warning remains in effect with snow beginning to move in from the south around 2-4 a.m.

Washington will be right in the battleground between a very warm air mass being pushed north from the tropics and a very cold, arctic air mass dropping south from Alaska. This will aid in storm development, but also means that a slight change in track is all the difference between whether you're on the warm side or cold side.

Forecasting modes are now coming to agreement on a path of this storm that brings it into the mouth of the Columbia River on the Washington-Oregon border and moves it generally east along the river.

For snow lovers, this is good because it will keep much Western Washington on the colder, north side of the storm, meaning a changeover to rain is less likely to occur, especially from about Olympia north to Bellingham.

But on the other hand, the storm doesn't appear to have as much moisture on its north side -- instead focusing 10-20 inches of rain equivalent on its south side into Oregon.

This means the general story is that this event will likely be snow start-to-finish -- so no warm slush fest at the end -- but not quite as much snow as initially feared, at least from Seattle north to the border. Those of you Tacoma south are still facing daunting amounts of snow.

Overall, figure less snow as you go north (although some of you in the far north aren't getting by scot free -- you're just getting your snow today. Some spots in Whatcom County are well over a foot (Sumas reports 18 inches on the ground now.)

To break this down, points from Olympia south to Portland and out to Pacific County could see 8-12" of snow. For Tacoma area, we're looking at 6-8 inches. For greater Seattle it's now about 4-6" with the higher amounts toward the foothills. As you go north, the snow totals now get less. Everett, for example, is looking like 2-4" now -- although that's on top of what you're getting in the convergence zone Tuesday. By the time we get to Bellingham, they may just be windy and cold with blowing snow and low wind chills as the Fraser Wind ramps up.

One special note for those in southwestern Washington corridor up to about Olympia -- the National Weather Service says there are indications you could go through a period of freezing rain toward the end of the snow event as a little warm air gets in to that area in the midday hours, adding to travel woes down there.

Now, how about some good news for those who are not happy with snow? Models now indicate snow tapers off late Wednesday afternoon or early evening, which would help give road crews time to clear the roads in time for Thursday. No changeover to rain though, so no help from warmer weather to melt the snow, but on the other hand, it should prevent any heavy snow weight issues like we saw in 1996.

Models show areas from Seattle north stay dry and cold Wednesday night with likely icing concerns Thursday morning. Another wave of moisture passes across southwestern Washington on Thursday that could bring another round of snow to the south Sound and southwestern Washington, but not as much and Seattle is on the extreme northern edge.

By Friday, we warm up but stay quite stormy with more traditional steady rains, gusty winds and heavy mountain snow continuing. Cascades could see several feet by the end of the weekend, maybe even approaching 70-80 inches of new snow in the central Cascades using rough model estimations.

General Recap

* Snow showers around Tuesday -- most in Convergence Zone areas, least in Seattle to Burien corridor.
* Steady snow develops from south to north around 2-4 a.m. Wednesday, last a good 12 hours to 2-4 p.m.
* Heaviest snow totals in Olympia & Southwestern Washington (8-12"), possible ice-freezing rain toward end of event.
* Tacoma area and central coast, 6-8"
* Seattle area: 4-6"
* Everett area: 2-4"
* Northwest Interior: 1-3", gusty northeast winds.
* Snow just ends in the afternoon/evening, no change to rain except perhaps far southern Washington
* Cold Wednesday night with below freezing temps for icy commute Thursday morning.
* Perhaps some more snow Seattle south on Thursday, best chance south of Olympia.
* Warming up Friday into the weekend, but remaining stormy with rain, wind and snow.

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