We have turned the corner regarding Northwest weather, and a cold, wet corner it is. But there is a silver lining--a good chance of Thanksgiving skiing in some of the Cascade ski areas, with Whistler being a shoo in.
Sunday morning we had the classic snow/cold upper level pattern, with a ridge of high pressure offshore and a tight trough over the Northwest.
But this will change substantially this week, with a deep trough building offshore. This will keep us cool (highs in the 40s), with a lot of moisture coming up from the southwest. California and Oregon will get hit particularly hard.
You can tell the atmosphere means business by viewing the latest infrared satellite picture. A huge swath of clouds ready and eager to move into the West Coast.
Take a look at the total precipitation expected during the next week (based on the NWS NCEP GFS model): large amounts (5 inches plus) in the mountains from northern California to British Columbia).
You can not expect much relief from the cold and wet for a long time. The best way to look forward is to examine the forecasts from a large ensemble system. Here is the NAEFS ensemble almost to Thanksgiving at Seattle. The whiskers show the range of the forecasts and the most probable value by the horizontal line in the yellow boxes. 50% of the forecasts are contained in the yellow boxes. Temperatures rising to roughly 6C (43F). Rain most days. Cloudy for nearly the entire period.
The kind of weather that should make Amazon yearn for a second HQ in a warm, sunny place.
My rule of thumb for mountain snows in fall is that when Seattle is less than 50F there will be snow at Stevens pass and above. Looks good. I suspect a number of ski areas will open next week...all they need are a few more storms.
from Cliff Mass Weather and Climate Blog http://ift.tt/2lXORnI
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