MOUNTAIN WEATHER FORECAST

Stevens Pass Mountain Weather Forecast

Day and Time: Sunday 0630

Current Observations:

24hr Precipitation:  Snowing - .19” w – 3” snow

Pass temperature: 29

Pass level winds: 5-15 E

Barometer: 1011mb’s and falling 

Sky: Overcast/fog

Radar: The satellite radar is lit up this morning with widespread precipitation throughout the state.

The Forecast: A mixed rain and snow event is taking shape for today.  Temperatures are on the rise with freezing levels expected to peak between +-4500’ and 5000’ later today.  There will be a brief break in the action tomorrow morning with heavy snow anticipated to arrive tomorrow afternoon/evening.     

Long Range: Heavy precipitation with freezing levels near or slightly above 4000’ can be expected on Tuesday.   There will be another break on Wednesday with rising freezing levels (+-5500) and a chance rain showers on Thursday.    

The Science: There is a triple point storm with a strong SSW flow component entering the region this morning. The leading warm front should pass over the Cascade Crest in a few hours.   Once the front passes, the east flow will be overtaken by warmer SW flow.  Freezing levels rise to +-4500’ or even a touch higher around noon or so today.  The following cold front moves through late tonight which will shift the winds to WSW. This will reduce the moisture to light showers.  

Another juicy front hits tomorrow afternoon/evening with strong westerly (convergence ) flow forming early Tuesday morning.   Freezing levels will start out around 4000’ Monday night and then rise to 4500/5000’ on Tuesday.      

Confidence in freezing levels and timing is low due to complexities within the storm.

Values from 4am today through

 4am tomorrow.

Precipitation: Today 24hr water:.5+  snow: 2-4 base, 3-5 upper mountain Tomorrow’s 24hr water: 1  snow: 8-12 Trend and Timing: Heavy snow begins late tomorrow afternoon.

Temperature: Low: 30    High: 34 Freezing level: +-4500’ Trend and Timing:    Freezing levels peak @ 4500’ this evening and fluctuate between 4000’ and 4500’ through the night.

Winds Base: 5-10 E –shifting SW Ridge Top: 5-15 SSE Trend and Timing: Surface east flow with southerly flow aloft will shift SW tonight and then back to easterly tomorrow.