MOUNTAIN WEATHER FORECAST

Stevens Pass Mountain Weather Forecast

Date: Saturday, March 14, 2020

Current Observations:

24hr Precipitation: 5” snow / .45” SWE

Temperature profile: 21 base / 16 mid mtn

Pass level winds: Moderate easterly

Barometer: Steady at 1002

Sky: Overcast, snowing lightly

Radar: Widespread showers across the PNW, heaviest at the WA/OR border

The Forecast: Cold and mostly cloudy today with gusty east winds, becoming clear overnight, sunny and cold Sunday. 

The Science: A large low pressure trough arrived from the north yesterday and continued south overnight, with the frontal band now sitting just south of the WA/OR border. The center of the low passed well to the west of the Crest, so precipitation and snow accumulation near and west of the crest was unimpressive, however the circulation around the low lead to an upslope snow event on the east side of the crest (“wrap around moisture”). To illustrate this unusual pattern: Mission Ridge received 15” of snow overnight while Mt. Baker recorded 1”. Cold air has intruded with the front and the pressure gradient driven by the location of the low is bringing gusty easterly winds thru all Cascade passes this morning.

The low slowly drifts south along the coast today and tomorrow, while high pressure builds in the Pacific. This setup will lead to Fraser River outflow out of BC, bringing east winds and cool temperatures across most of Washington, particularly the northern interior near Bellingham.  As the low continues south, snow showers will end across the northern half of Washington this morning, and in all areas by tonight. Sunday will be cool and mostly sunny across the state.

Long Range: Stationary high pressure in the Pacific will deflect any storms well to our north most of next week, the week will start out cold but temperatures will come up quickly Monday afternoon and Tuesday with freezing levels between 4000’ and 5000’ the remainder of the week.

Confidence: Good

Values from 4am today through 4am tomorrow.

Precipitation: Today 24hr water: >.10 snow: trace Tomorrow’s 24hr water: 0  snow: 0 Trend and Timing: Light snow showers becoming very light and ending Saturday, dry on Sunday.

Temperature: Low: 15   High: 24 Freezing level: 1000’ Trend and Timing:    Cool temps all day, further cooling tonight.

Winds Base: E 5-10 Ridge Top: E 15-25 Trend and Timing: Steady east winds today with higher gusts possible in the afternoon.