Cool and Sunny For The Weekend, and Interesting in The Long Range

 The coldest weather of the winter is coming to the Northwest, which isn't saying much considering how this winter has gone so far. 

Most of Western Washington has been stuck in fog today and will continue to be, keeping temperatures confined to the 30's. A weak disturbance will cross the area tomorrow bringing some showers to the area but it shouldn't amount to much.  Temperatures will be similar to today. I want to note that any residual moisture on Friday morning would fall as a mix of rain and snow or as snow showers, but most models clear out all the moisture by then.

Moving on to the weekend, we will get clipped by a very cold air-mass moving into the middle of the country. Temperatures will plummet, especially in Eastern Washington as a cold air pool will begin to build. In Western Washington, highs will be in the upper 30's to low 40's with lows in the mid to upper 20's. There is no moisture present during this time, and clouds should clear out making for a nice, sunny weekend!!

After that air-mass moves on, the rest of the week should remain fairly chilly but dry with no signs of precipitation until the 24th-25th!! 

Long Range

Ensembles indicate that the ridge over us will retrograde into Alaska next week. This ridge is essentially a "block" which would cause the Pacific Jet that has been roaring all winter to retract. This pattern is usually a good indicator for a period of cold in the west.

The ensemble mean for the European models has a strong signal for this pattern and this is generally the most accurate one giving me a fair amount of confidence for a period of extended cold in the west. However, the other major model, the GFS, does not agree and has a different solution.
The GFS has less amplitude with the ridge, causing it to flatten and not retrograde. This would definitely not be a cold pattern for the west but the good news (for fans of cold weather) is that this is the only model that has been showing this solution. The Canadian model is also in agreement with the EPS and has a strong retrogression signal.
At this point I would say there are 70/30 odds for an extended period of cold in the west. This is still quite far out and it's important to focus on the bigger picture and not the details as those will change as get get closer.

Have a great week!!

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