MOUNTAIN WEATHER FORECAST

Stevens Pass Mountain Weather Forecast

Day and Time:  Friday 0700

Current Observations:

24hr Precipitation:  .11swe, 4” of snow

Temperature profile: 23base,  20 ridges

Pass level winds: light and out of the southeast

Barometer: 996mb’s and rising

Sky: OC

Radar: Light scattered snow showers falling in the central and north Cascades with rain out along the coast.

The Forecast:  Light snow showers will persist through tomorrow with drier and cooler air moving in on Sunday.

Long Range:  The next snow of interest arrives on Tuesday.  

  

The Science: The low pressure system that has been stuck spinning off the PNW coast will slowly drift south over the next 24-36hrs.  As this system makes its way out, it will drag the moisture with it and draw cold air in from the NE interior.   Hence the dry cooler airmass expected on Sunday.

In the long-term, there is a shift in the pattern underway.  NW flow moving up and over a high pressure system (centered over Hawaii) will bring a unstable atmosphere into the PNW through next week.  Temperatures will remain low with the a few winter storms developing.  It’s still a fair way out to bank on specifics, but it is safe to say that winter will carry on.   

Forecast confidence: Good in the short-term, fair to poor in the long-range.

Values from 4am today through

 4am tomorrow.

Precipitation: Today 24hr water: .25 snow:  2-4 Tomorrow’s 24hr water: .25  snow: 2-4 Trend and Timing: Light passing snow showers will continue through tomorrow.

Temperature: Low:20   High: 30 Freezing level:  +3000” Trend and Timing:    Freezing levels will spike to 3-3500’ this afternoon and then begin to fall overnight.

Winds Base: 05 ESE Ridge Top: 5-10 ESE shifting W then back to E Trend and Timing: A short upper-level shift to west flow will be possible today, the general surface flow will be east.