Mountain Weather Forecast

Weather Synopsis for Thursday night through Thursday

1820 Update: Hurricane Ridge weather for Friday afternoon

The first slug of warm frontal moisture has arrived along the coast this afternoon. Generally light precipitation will spread inland this evening. Snow levels will take a sharp drop at the onset of the precipitation, but warm, strong WSW flow will quickly override the cooler air trapped over the Cascade mountains Friday night. There may be a period of mixed precipitation or freezing rain for Snoqualmie/White Passes early this evening and then for Stevens Pass later this evening before a switch to rain. 

Eventually, snow will turn to rain for most locations. Cooler snow levels will hang on the longest in the Washington Pass/east Hwy20 corridor through late morning or mid-day Friday.  As the second pulse of moisture arrives on Friday, the warm front will begin to lift north, shifting the axis of heavier precipitation into British Columbia. This may allow for a late day sun breakout at Mt. Hood with freezing levels around 10,000 ft. Winds will be the other big story with this pattern. WSW winds that increased this afternoon will become stronger overnight and continue through Friday. 

We may be headed toward an exceptional mountain wind event Friday night through Saturday morning. Forecast models show WSW winds buffeting most areas in Washington State with 5000' foot winds in the 40-60 mph with much higher gusts likely. The frontal boundary now looks to take a bit longer to sweep through Friday morning. That translates to more wind and rain at high snow levels Friday night. A strong cold front will sweep through Saturday mid-morning with snow levels plummeting to near sea level by late Saturday afternoon or evening. Winds will remain gusty through Saturday afternoon. A Puget Sound Convergence Zone may quickly pile up locally heavier snow accumulations.