Mountain Weather Forecast

Time and Day: 0700 Sunday

The Snapshot: Mixed precip today, mild and cloudy this afternoon and Monday morning, with snow returning Monday night.

The Science

Current Observations:  Light mixed precip is falling from the base area to the upper mountain currently. East flow is maintaining temperatures just below freezing, and there was 2” of snow overnight. The barometer has gone up a few ticks but should begin to fall again soon.

The Forecast: A deep low pressure center is well offshore in the Pacific and is spinning a warm front from south to north this morning. The front will lift across Western Washington mid-morning, bringing moderate precipitation to the Central Cascades and heavy precipitation to the Olympics and North Cascades. East flow through Stevens Pass is currently maintaining temperatures below freezing, although the precip type coming out of the sky is definitely “mixed.” Pressure gradients should ease and switch to onshore mid-morning, which will be the end of our easterly cool air. Temperatures will rise and precip type should change from a wintry mix to good old rain.

The good news is that models show the bulk of the moisture staying well to the north of Stevens Pass after the warm up. Late Sunday afternoon and night there will be a drying trend. As the low pressure center moves onshore, the front will sag across the state bringing renewed precipitation Monday afternoon and evening. This precip will likely start as rain, but freezing levels drop behind the front and cool, westerly upper level flow develops for a return to snow. Stay tuned for details.

The Long Range:    West-Northwest flow should maintain moderate snow Tuesday and Wednesday at 2-3,000’ freezing levels. Thursday looks mostly dry, with another system bringing moderate snow Friday.   

24hr values daily 4am to 4am.

Precipitation: Sunday’s 24hr water: .5   snow: 2-6” Monday’s 24hr water: .75-1.0  snow: 6-10” Trend and Timing: Moderate precip mid morning Sunday, then mostly dry until Monday midday.

Temperature: Low: 28    High: 38 Freezing level: 6500’ Trend and Timing:    Temps should rise mid-day Sunday and overnight.

Winds Base: E 0-5, then variable 0-5 Ridge Top: ENE 5-10, then SSW 10-20 Trend and Timing: Mid morning switch from easterly to westerly, remaining SSW throughout the night.