Mountain Weather Forecast

Weather Synopsis

A frontal system approaching the Pacific Northwest Coast on Saturday afternoon spreads a wide swath of moderate to heavy rain and snow out ahead of it. Behind the band of precipitation is a warm front, with high water vapor values generally aimed for northern Oregon through central Washington. These are the airs tapped for the highest precipitation totals with this system - most notably the southern Cascade volcanoes.

Precipitation should peak in the evening hours through the expected warm frontal passage between noon and 2 AM. In advance of this front, most areas will experience increasing SW winds, and moderate to heavy snowfall above the 2500-3500 ft rain/snow line. Snow levels in the Pass should stay below 3000 ft during this time as E flow keeps temperatures near or just below freezing at Snoqualmie Pass. However, behind the front, expect 20-30 mph ridgeline WSW winds to overwhelm the weakening low-level E flow at the same time as the warm front raises snow levels to around 4500 ft from the central Cascades southward. Snow shower activity should be mostly light behind the front and will decrease through the day on Sunday, but don't expect much of a change in snow level except in the Washington Pass area where the colder air may take longer to scour out. Mt Baker was originally expected to get more snowfall, but precipitation amounts have cut back significantly since this time yesterday.

Storm totals should be in the 6-10" range for Snoqualmie Pass, Mt Baker, and Mt Hood. Stevens Pass should expect 6-12" and Paradise can expect 14-22". Locations east of the Cascade Crest will pick up 2-6" of snow.

A closed low moving towards the Oregon Coast Sunday night will bring increasing light to occasionally moderate rain and snow to the southern Cascade Volcanoes, most notably Mt Hood. This precipitation peaks overnight and tapers on Monday. Mt Hood could pick up 4-8" of snow above the 4000-4500 ft rain/snow line. The northern extent of the precipitation remains uncertian.