MOUNTAIN WEATHER FORECAST

Stevens Pass Mountain Weather Forecast

Day and Time: Friday 0700

Current Observations:

24hr Precipitation: 0 

Pass temperature: 17

Pass level winds: 5-15 E

Barometer:  1018mb’s holding

Sky: foggy

Radar: Satellite images have dry conditions throughout the state.  The inversion cloud layer is still locked in place over the eastern basin. The leading cloud deck of the approaching system is about 100miles of shore.

The Forecast:  This cold and dry weather will persist for one more day.  Clouds roll in tonight with light snow beginning to fall in the mountains early tomorrow morning.  Tomorrow afternoon and night will be mostly dry with warming temperatures.  Snow begins on Sunday with 4-6”  likely by Monday morning.   

Long Range: Snow showers will linger into Monday with the next stronger storm poised to hit the mountains Tuesday/Wednesday.  The winter storms keep rolling in with +-30” of snow possible by the end of the week.

  

The Science:  The series of storms approaching the PNW will shove out the high pressure over the next 24hrs.   This will all start with a weak warm front brushing the coast late tonight.  A thin strip of moisture out ahead of the front will provide an inch or two of snow tomorrow.  The following cold front arrives on Sunday with a decent amount of moisture to play with.    

The main game will be how the warm air coming in from the southwest plays with the cold air trapped in the eastern basin.  Freezing will be on the rise and the east flow will eventually be overtaken.  The good news is that there seems to be plenty of cold air associated with Sunday/Mondays cold front to keep the freezing levels at or below 4000’.   

Values from 4am today through

 4am tomorrow.

Precipitation: Today 24hr water:<.10   snow: trace Tomorrow’s 24hr water: .25  snow: 1-3 Trend and Timing: Light snow arrives after 4am tomorrow and ends just after noon.  The next round of snow arrives Sunday morning.

Temperature: Low: 17    High: 25 Freezing level: 500’ – 2000’ Trend and Timing:    Pass level temperatures will continue to be low through the night.  Freezing levels along the western slopes will rise tomorrow with daytime temperature peaking near 30.

Winds Base: 5-10 E Ridge Top: 5-10 ESE Trend and Timing: East flow at the surface with SE flow aloft will be the wind pattern through tomorrow.