Major Mountain Snow, Arctic Blast Looming

 FastCast—Saturday, Feb. 18 to Tuesday, Feb. 21:

An unsettled but mostly calm weekend is ahead across the region. Expect mostly cloudy conditions with a chance of showers, likely totaling 0.1-0.2 inches in the lowlands. Highs will reach the mid to upper 40s, with lows in the upper 30s to mid 40s. Through the weekend, Snoqualmie Pass will receive 4-8 inches of snow, with 8-16 inches at the higher passes. Some travel delays are possible. A much more robust system arrives on Monday, continuing through Tuesday, bringing 0.4-0.9 inches of rain to the lowlands and major mountain snows. Expect totals of 12-24” at Snoqualmie Pass and 24-36” at Stevens and White Passes, though those amounts are still changing. The lowlands will begin turning colder late Tuesday, but details about that transition, and potential snow chances, remain uncertain. Be sure to stay tuned to upcoming blogs.

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Continue reading the full blog below!

Major mountain snows are ahead for the Cascades, with an Arctic blast looking likely for the entire region around the middle to end of next week. Let’s take a look at some forecasts.

Below is the European model forecast for snow through Tuesday night.

This forecast shows major mountain snow, with 24-36” at Snoqualmie and White Passes, and up to 36-48” at Stevens Pass. Most snow will fall from Monday to Tuesday, but amounts are still changing as models struggle with snow levels and temperatures on Monday, which could change snow totals.

Let’s compare this with the NWS NBM high-resolution forecast, also showing snow through Tuesday night.

This forecast shows a bit less snow than the European model, probably a bit more realistic as of now. This forecast shows 12-24” at Snoqualmie and White Passes and 24-36” at Stevens Pass. 

Travel delays are expected, so continue monitoring the latest alerts and forecasts regarding mountain snow.

All of this mountain snow through Tuesday means that the lowlands will be picking up the first significant rain of February. Below is the European model forecast for rain through Tuesday night.

Expect 0.4-1.5” of rain in the lowlands, with even more possible between Everett and Bellingham. On the coast, expect 1-1.5”. 

Finally, it is now very likely that much colder than normal temperatures will occur from the middle to end of next week and possibly beyond. Below is the NWS Climate Prediction Center outlook for temperatures from February 23-27 (next Thursday to the following Monday).

Wow! The scale is maxed out over the Western US, with the almost the entire Pacific Northwest under an 80-100% probability of below average temperatures. This high a probability suggests that temperatures will be significantly below average.

However, details on these temperatures are still uncertain, so stay tuned to upcoming blogs! What is certain is that very cold temperatures and potentially hazardous wind chills are in store, so have that in the back of your mind as we enter next week. Stay tuned!