Mountain Weather Forecast

Weather Synopsis

A very strong storm is plowing into the Pacific Northwest this afternoon, driven by a strong jet stream that's positioned over the WA/BC border. Snow levels are on the rise this afternoon and should peak in the 5000-5500' range across the area this evening.  Precipitation rates will be very heavy during this stretch, between 0.10-0.30"/hr, that's several inches/hr above the snow-line. Winds are ramping up and will become extreme in all areas later this afternoon and evening. 

A strong cold front will push southeast later this evening, bringing a sharp cooling trend first to the Olympics and Mt. Baker area, and spreading to the south WA Cascades after midnight.  Unfortunately for Mt Hood, they won't see the cooling overnight, hovering around 5500', but will see anywhere from 2.5-3" (!) of water in just 12 hr.  The south Cascades near and south of Hwy 12 will also see some of the highest precipitation totals tonight. Behind the front in the north, we'll see heavy rain and snow turn to blustery snow showers overnight. 

This north/south temperature divide will be a theme moving forward.  On Thursday, we'll see moderate snow showers with low snow levels over the WA Cascades, heaviest near a Puget Sound Convergence zone that sets up over Skagit and Snohomish county and is likely to pepper Stevens Pass and the Mt Loop at times.  South of the Columbia River, Mt Hood will see a few hours of showers before steadier warm frontal moisture returns Thursday afternoon. Those extreme winds will also follow a north/south divide, with winds falling off over the north Cascades, transitioning to extreme winds down near Mt Hood. 

Warm frontal moisture (weak atmospheric river) will lift northward Thursday night, before sagging south on Friday, but overall storm impacts will pack less oomph than Wednesday's storm. There won't be much warming in this round for the WA Cascades, so look for snow to continue to pile up on Thursday night and Friday, with milder conditions for Mt Hood.