MOUNTAIN WEATHER FORECAST

Stevens Pass Mountain Weather Forecast

Day and Time:  Tuesday 0700

Current Observations:

24hr Precipitation:        0

Temperature profile:     35 base, 34 ridge

Pass level winds:            Calm, easterly

Barometer:                    1012mb’s and beginning to fall

Sky:                               clear

Radar: A band of moisture is entering Hood River Oregon and slowly moving north.  The rest of Washington is mostly dry and clear.                  

The Forecast:  One more dry day with temperatures peaking near 50.  A prolonged wet period begins tomorrow with rain starting early tomorrow morning.

Long Range:  Thursday will be between storms with dry and cloudy conditions.  The next wave of moisture moves in on Friday with moderate to heavy mixed rain and snow through the weekend.

  

The Science: Satellite images have 3, yes 3, triple point frontal systems moving along a developing storm track heading our way.  The first wave arrives tomorrow with the second expected on Friday and then more for the weekend.  

Snow or rain?  Well, both.  The storms are coming in from the southwest which is warm.  However, a low pressure system in the Gulf of Alaska, and the associated cold fronts, will provide some cooler air from time to time.  Thus, the freezing levels will bounce between 4000’ and 5500’ through the storm cycle.  

The storm water equivalent (SWE) is impressive with a potential of +4” by Sunday.  If we get some luck with the timing of the freezing levels, we could see some snow accumulation – although, given the season, it will be very wet.   

Forecast confidence: Good for today.  The incoming story track has complexities which drops confidence for timing and intensities.  Safe to say, it will be wet.

Values from 4am today through

 4am tomorrow.

Precipitation: Today 24hr water: .10  snow: 0 Tomorrow’s 24hr water: .5-.75  snow: 0-2  lower mountain,  2-4 upper.   Trend and Timing: Rain will enter the mountains after midnight and increase through the day tomorrow.  Periods of snow above 4500’ will be possible.

Temperature: Low: 34  High: 52 Freezing level: 7000’ -5500 Trend and Timing:    Freezing levels will begin to fall tomorrow.

Winds Base: 0-5 E shifting W Ridge Top: 0-10 E Shifting WSW Trend and Timing: East flow will shift to westerly overnight.  Frontal wind gust can be expected as these storms come and go.