The southern portion of a so-called Atmospheric River begins to impact Washington state on Sunday. Expect showers to begin after 2pm.
A lack of east winds through the passes should allow for warming temperatures through the afternoon, which has already caused precipitation to change over to a rain/snow mix at Snoqualmie Pass. Avalanche control has seemed to be an ongoing theme at Snoqualmie Pass lately. Be sure to check pass conditions if you head over the pass this week. It has been an epic snow year indeed!
Back at home I know many folks are still repairing and cleaning up from the major Feb 13th gap wind storm.
Taking a closer look, that windstorm was right up there with the big ones measured by pressure gradient between Yakima-Seattle (YKM-SEA), a whopping 13.7 mb! 30 ms = 67 mph (the 2/13 peak gust)
Keep us tuned in! We take a high interest level in forecasting the timing and accuracy of these wind events, and are usually first warning about them.
As a reminder, gap windstorms are a unique event reserved for Snoqualmie Valley, and other east lying Cascade foothill locations (e.g. Gold Bar, Enumclaw, Columbia Gorge), downslope of major gaps in the Cascades (e.g. Stampede gap). They are caused by relatively higher pressure (cold air) in E. WA being pulled over by a Low pressure system off the coast.
Back to the forecast, steadier rains and gusty southerly winds (25-35 mph peak gusts possible) Sunday into Monday.
As much as this Atmospheric River (AR) has been advertised, it is relatively short-lived (turning showery later Monday into Tuesday).
We are watching the colder air expecting to be pulled in behind the AR early Tuesday, as lingering precipitation could fall as wet snow down to 500 ft. Little to no accumulations expected at this point.
After a mostly dry Wednesday expected, we remain in this cool showery period for much of the remainder of the week. Can’t rule out a wintry mix into Thursday or next weekend. We’ll keep an eye on it.
Looking out a bit, we look to begin March in a very similar pattern. Youth Baseball and Softball practice is right around the corner! 🙂 Between rainouts and frozen hands, often a rough start in Western WA.
Have a great week!
[Originally published at Snoqualmie Weather blog. During active weather, follow more frequent updates @snoqualmiewx or on Facebook]
