MOUNTAIN WEATHER FORECAST

Stevens Pass Mountain Weather Forecast

Wednesday, March 11, 2020, 1100

Current Observations:

24hr Precipitation:        .01, swe,  1” of snow

Temperature profile:       30 base,  25 ridge

Pass level winds:              moderate westerly

Barometer:                      holding at 1013mb’s

Sky:                             overcast and lightly snowing

Radar: snow showers in the weakening convergence zone with little moisture making it to Stevens Pass

The Forecast:  Diminishing snow showers with falling temperatures can be expected today.  Mostly dry tomorrow with snow arriving on Friday.  

The Science: The cold front expected to move over the mountains last night has stalled and is currently draped over the western portion of the state.  As it creeps its way east, temperatures will fall with light intermittent snow shower left in its wake.  Pressure gradients relax over the next 12hrs as cool dry northerly flow streams into the region.

A tightly packed low pressure system will track south along the PNW coast on Friday bringing snow to the mountains along with further falling temperatures.   Models have this system moving fast through the region, which equates to short lived pulses of precipitation – not likely to be a huge snow producer.  As the system heads south, it will draw in a cold dry air mass from north.  Freezing levels will descend to sea level with temperatures in the mountains dropping to the low teens or even single digits early Saturday morning.  

   

Long Range.  Snow shower will likely linger into Saturday with Sunday trending cold and clear.  Warmer air begins to return next week with no significant moisture expected.  

Confidence: Good  

Values from 4am today through 4am tomorrow.

Precipitation: Today 24hr water: .10  snow: trace Tomorrow’s 24hr water: 0   snow:  0 Trend and Timing: Light snow diminishing today, dry tomorrow.

Temperature: Low: 32   High: 26 Freezing level: 3500’ – 2500’ Trend and Timing:    Freezing levels will fall to +-2500’ this afternoon/ evening

Winds Base: 5-10 NW Ridge Top: 5-15 WNW  Trend and Timing: Winds will begin to diminish today and shift NW.