Thursday, March 30, 2023

Heavy Mountain Snow & Colder Temperatures as Active Weather Returns

FastCast—Friday, mar. 31 to Monday Apr. 3:

Active and colder weather is back in the Pacific Northwest. Highs on Friday will drop into the mid to upper 40s, with rain returning by evening. Showers and a chance of thunderstorms will persist through Monday, with the heaviest precipitation likely from Friday night to Saturday morning. Expect rain totals by late Sunday of 0.5-1.25” for the lowlands, highest in the Cascade foothills and under Convergence Zone bands (likely between Seattle and Arlington), and 2-3” on the coast. Mountain snow will be the biggest impact of this system. Generally, expect 12-18” of snow at the passes through late Sunday, with the heaviest snow from late Friday to early Saturday. Snow levels will hover around 1,000-2,500 feet, with all precipitation at the passes falling as snow. In the lowlands, expect chilly highs in the mid 40s to low 50s, with lows in the mid to upper 30s. There is a slight chance of rain/snow mix or very brief snow in heavy showers, mainly in the late evening to early morning hours. No accumulations or impacts are expected in the lowlands. Additionally, expect breezy conditions on Friday afternoon & evening, with gusts of 25-35 mph across the lowlands.

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Continue reading the full blog below!

A few days of active weather are ahead for the Pacific Northwest. The biggest impact will be heavy mountain snow from late Friday to early Saturday, continuing in showers through the weekend. Below is the European model’s forecast for total snow through Sunday night.


Expect 12-18” in the Passes, with 2-8” in the Oregon Coast Range. Travel impacts are likely, mainly from late Friday through early Saturday. Snow will turn more showery from Saturday morning onward, which is why there are some locations in the lowlands showing snow on this forecast. Lowland snow accumulation is highly unlikely, but brief snow or rain/snow mix is possible in heavier showers, mainly in the mornings and evenings/overnight.

This system and showers this weekend will bring rain for the entirety of Western Washington, as seen on the European model’s forecast for total rain through late Sunday.


In the lowlands, expect 0.5-1.25”, with the highest amounts in the foothills and from Everett northward. The coast will receive 2-3”, and the Willamette Valley will get 1-2”. Eastern WA will pick up 0.1-3”, except 0.4-0.9” from Walla Walla to Spokane and eastward.

In addition to the rain and significant mountain snow, you will notice a major cooldown, with high temperatures over 10 degrees below average. Below is the European model forecast for highs on Friday.


Lowland highs will drop all the way to the mid 40s. Some locations will reach the upper 40s. Eastern Washington won’t be much better off, only in the mid 40s to low 50s on Friday. Similar temperatures statewide are expected to continue through Monday.

Breezy conditions are also expected across the lowlands on Friday evening, prior to the frontal passage late Friday night (which will change precipitation from steady to showery). Below is the high-resolution NAM forecast for gusts at 8 PM Friday.


Breezy conditions are expected across the area, with gusts of 30-35 mph expected, except up to 40 mph along the coast and near Puget Sound.

Finally…a glimmer of hope for more spring-like weather ahead in April! The latest NWS Climate Prediction Center (CPC) temperature outlook for April 7-13 is below.


At long last, one of these outlooks shows a 33-40% probability of above average temperatures for April 7-13! This is progress toward more seasonable weather. Stay tuned!

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