Mountain Weather Forecast

Weather Synopsis

High clouds have snuck under an upper level ridge this afternoon leading to partly sunny skies across the region. After a chilly start, mid-mountain temperatures have climbed to near or above freezing through 2 pm. Offshore flow has created breezy SE ridgeline winds in many locations as well. 

As the upper level ridge crosses the Cascades tonight and settles over the inland NW on Thursday, we'll see those mild temperatures and high freezing levels continue overnight, peaking on Thursday with freezing levels 9000-12000' and mid-mountain max temperatures on Thursday near or above 50F.  A stationary frontal boundary near the B.C. Sunshine Coast will continue to send high clouds our way this evening, but high clouds are likely to thin after midnight through the bulk of Thursday.  The extent of the overnight clearing will help decide the depth of temperature inversions that form along lower/mid slopes and in valleys. The East North zone including Washington Pass will be relatively cooler than the rest of the forecast region overnight. 

While Thursday will be a full-on spring day, we can expect another round of breezy S or SE ridgeline winds. An approaching frontal boundary Thursday night will spread clouds and eventually precipitation inland. We can expect strong southerly winds for the usual suspects, Mt Baker area, Hurricane Ridge and perhaps Crystal Mt late Thursday night.

During and after the frontal passage through Friday morning, showers should be unremarkable except near the Mt Baker area during the bulk of the day and then a Puget Sound Convergence zone may form along the central Cascades during the afternoon hours between the I-90 and Hwy 2 corridors. Expect moderate westerly ridgeline winds behind the front Friday. Snow levels will fall, but the coldest air will hold off for the weekend.