MOUNTAIN WEATHER FORECAST

Stevens Pass Mountain Weather Forecast

Day and Time:  Friday 0700

Current Observations:

24hr Precipitation:  0 and snowing lightly

Temperature profile: 20base, 19ridge

Pass level winds: light and westerly

Barometer: 1013mb’s and beginning to fall

Sky: Increasing clouds

Radar: Light precipitation starting to enter South Sound region.   

The Forecast:  Increasing snow today, intermittent snow showers can be expected through the day tomorrow.

Long Range: Cloudy, with light diminishing snow showers will be on the menu for Sunday with the start of the new week trending dry.  Temperatures will remain on the cold side through most of next week as well.   

  

The Science: The leading edge of the approaching frontal system is currently moving into Puget Sound.  This is another triple point, so expect a rise in temperatures associated with the first warm front today.  The following cold front is timing out to pass east of the crest late this afternoon; dropping freezing levels and shifting the snow to showers through the night.  

An atmospheric wave within the upper level trough will be the driver of the moderate snowfall this afternoon.  Convergence conditions will form, but the target is very much in question.   Freezing levels will peak (+3000’) this afternoon and fall in the wake of the cold front.   

Forecast confidence: Snow fall confidence is fair due to the convergence zone target question.

Values from 4am today through

 4am tomorrow.

Precipitation: Today 24hr water: .5- .75  snow: 6-10 Tomorrow’s 24hr water: .25  snow: 1-3 Trend and Timing: Light snow this morning increasing after 2pm today.  Heaviest period (depending on the convergence target) will be between 2pm and midnight.  Snow shift to showers overnight with convergence showers possible.

Temperature: Low: 19   High: 28 Freezing level:  1500’ - 3000’ -2000’ Trend and Timing:    Freezing levels will rise to 3000’ by noon or so, then fall through the night.

Winds Base: 0-10 WNW Ridge Top: 5-10 W Trend and Timing: Winds will be generally light to moderate and WNW.