Mountain Weather Forecast

Weather Synopsis

On Saturday afternoon, a low-pressure center has shifted east of the region, returning the PNW to cool, unsettled weather and increasingly widespread afternoon convective snow showers. The trough responsible for nearly a week of cold, snowy weather will finally slide east this evening. In the wake of the departed low, westerly winds have picked up at ridgelines from the Central Cascades south to Mt Hood and should peak Saturday evening. Expect decreasing light to moderate snow showers for most mountain areas tonight. Convergence may enhance snowfall with 3-6” amounts between Snoqualmie Pass and the Mountain Loop while other parts of the west slopes of the Cascades pick up 1-3” before weak ridging cuts off moisture by Sunday morning.

Ridgeline winds will decrease for much of the region and we can expect broken to partly cloudy skies on Sunday morning while a weak and short-lived ridge passes overhead. Some afternoon clouds may bubble up and lead to scattered snow showers in the northeastern corner of the Washington Cascades during the day. Increasing high clouds move in from south to north during the day as the next frontal system approaches. Low-level easterly winds develop and increase, potentially becoming moderate at times near Snoqualmie Pass from late Sunday afternoon through early Monday.

Expect precipitation to begin affecting much of the region by early Monday morning. Strong southerly ridgetop winds should create stormy conditions with slightly increasing snow levels as the front slowly sags inland during the day. The system should produce snowfall for most of the region all day on Monday before the focus of snowfall narrows to the west side and crest of the Cascades into the evening. Snowfall should continue well into the night for many areas, and we're looking at around 6-12" of medium-density snow by dusk on Monday for favored locations such as the Washington Volcanoes, with lesser amounts elsewhere.