MOUNTAIN WEATHER FORECAST

Stevens Pass Mountain Weather Forecast

Date: Saturday, February 15, 2020

Current Observations:

24hr Precipitation: 7” snow / .6” SWE (no new snow overnight)

Temperature profile: 28 base / 26 upper mtn

Pass level winds: Light westerly

Barometer: 1014 falling slowly

Sky: Obscured, snowing lightly

Radar:  Widespread precipitation west of the crest

The Forecast: Moderate snow today, snow showers tonight and tomorrow, with moderate snow again Sunday afternoon at cooler temperatures.

The Science:  A triple point frontal system is beginning to make landfall this morning. The parent low is approaching in upper level NW flow, moderate snow has already begun to fall at Pass level. Warm frontal moisture will fall as snow Saturday morning, with more spotty showers after the cold front sweeps thru Saturday afternoon. Steady W/NW upper level flow on Sunday will keep snow showers coming, with convergence zones likely to set up between I-90 and the Mountain Loop highway.

Long Range: A high pressure ridge builds offshore on Monday, bringing a dry and sunny start to next week.

Confidence: Poor for exact location of convergence zones today and tomorrow. Good for precip type (snow J).

Values from 4am today through 4am tomorrow.

Precipitation: Today 24hr water: .5-.75 snow: 6-8” Tomorrow’s 24hr water: .5-.75   snow: 6-8” Trend and Timing: Moderate snow during the day today, ending overnight. Light snow Sunday morning with a brief period of moderate snow in the afternoon.

Temperature: Low: 25   High: 31 Freezing level: 3500’ – 1500’ Trend and Timing:    There will be a midday bump in freezing levels, before marked cooling overnight and Sunday.

Winds Base: W 5-15 Ridge Top: W 20-30 Trend and Timing: Winds will increase with frontal passage midday, becoming gusty. They will taper down this evening.