Mountain Weather Forecast

Weather Synopsis

Mountain temperatures may look like spring's version of tropical this afternoon but it's not all sunshine; upper elevation pre-frontal W-SW winds have been moderate to strong in many areas. Camp Muir has been gusting into the low 80s this afternoon with many lower elevation stations in the moderate to even strong range.

High clouds will quickly increase this evening and rain and snow will move into the Olympics and northwest Cascades. A sharp cold front will sweep through the area overnight with a quick burst of moderate precipitation and even stronger W-SW ridgeline winds, extreme on the highest peaks. When precipitation begins, snow levels may initially start in the 4000-5000' range but should quickly fall to 2500-3000' overnight. A fledging convergence zone will form before sunrise over Snohomish and Skagit counties, squaring up between western portions of Hwy 2 and the Mountain Loop Hwy.  However, the post-frontal westerly/onshore push behind this system will be brief as the upper low attached to the frontal system starts to pull away and along the coastline. As a result, the convergence zone will dissipate quickly in the morning with light scattered showers developing over the mountains in the afternoon, particularly along the west slopes of the Cascades. As the frontal boundary slows down on Wednesday, the backedge should hang around central WA leaving a fair amount of cloud cover near and east of the Cascade crest/Mt Hood with more low level moisture and clouds along the west slopes of the Cascades.

The upper low will drop further south along the coast Wednesday night and Thursday but begin to wrap around moisture in SE flow. Showers will return to the forecast on Thursday, this time with potentially steadier and heavier precipitation aong the east slopes of the Cascades. Snow levels will be on the cooler side around 3000'.