Mountain Weather Forecast

Stevens Pass Mountain Weather Forecast

Day and Time: Sunday 0600

Current Observations:

24hr Precipitation:   .2” SWE / 2-3” snow / 7% density

Pass temperature:  24F

Pass level winds: Light, easterly

Barometer:  1011 and steady

Sky: Obscured

Radar: Widespread precipitation across the PNW

The Forecast: Moderate snow with heavier showers possible during the day Sunday at cool temperatures, with moderate wind gusts. Snow ending Sunday night. Passing clouds, dry, and cool on Monday and Tuesday.

Long Range:  Tuesday should be dry and partly sunny with continued low freezing levels. The next system arrives late Tuesday night/Wednesday morning with widespread precipitation at low snow levels. The Puget Sound foothills may see a few inches Wednesday morning. Long range models have high pressure building over the region Thursday and Friday.

  

The Science: Last night’s front mostly favored the volcanoes, and even they saw less than the forecasted amounts. The PNW will be under a cool airmass with zonal (westerly) upper level flow today. Moderate snow is still expected during the day Sunday, with a convergence zone potentially setting up midday bringing heavier showers. 500 mb winds should turn more northerly Sunday evening, bringing clearing skies, ending showers, and continued cool temps for Monday.

“500 millibar winds” are at roughly 18,000’ and are considered the steering winds for major weather features. Therefore, we pay careful attention to the direction those winds are coming from as it informs our knowledge of the relative temperature and moisture content of an approaching parcel of air.

Values from 4am today through

 4am tomorrow.

Precipitation: Today 24hr water: .75  snow: 6-8” Tomorrow’s 24hr water: LT .10   snow: trace Trend and Timing: Moderate snow Sunday, heavier in convergence showers. Ending Sunday evening.

Temperature: Low:  20   High: 26 Freezing level: 2000-2500’ Trend and Timing:    Cool temps with slight warming Sunday afternoon.

Winds Base: E 5-10, then W 5-15 Ridge Top: NE 10-15, then W 15-25 Trend and Timing: Direction should shift to westerly Sunday morning, with moderate gusts possible during the day, diminishing overnight.