MOUNTAIN WEATHER FORECAST

Stevens Pass Mountain Weather Forecast

Thursday, November 21, 2019, 0730

Current Observations:

24hr Precipitation:           0

Temperature profile:       30 base,  32 ridge

Pass level winds:               light, NE

Barometer:                       1015mb’s and holding

Sky:                                    clear with patchy morning fog

Radar:                          Mostly clear and dry statewide

The Forecast:  Cold and clear today with temperatures reaching into the mid to upper 30’s.  Tomorrow will be the same with slightly warmer temperatures.  

Long Range:  Rain is expected Saturday night with intermittent snow showers on Sunday and Monday.  Light passing snow showers will persist through the middle of next week with Thanksgiving day trending dry.

 It does not appear, at this time, that there will be significant snow accumulation at Stevens Pass through the holiday weekend.  

  

The Science:  There is a slight temperature inversion this morning with cold air to the east and warm air advection pushing freezing levels up along the western slopes.  The warmer air will continue to move NE today with daytime high temperatures peaking near 40.  

The high pressure that has brought us this short stretch of nice weather, will slowly weaken and drift south over the next 24-36 hrs.  This will open the door for a storm to make its way into the region over the weekend.  Models have the incoming moisture arriving late Saturday with moderate precipitation in tow.  Freezing levels will start out at or above 5000’ and then slowly fall on Sunday.  Thus, expect rain changing to snow early Sunday morning with snow showers persisting through the day. 

Cool unstable NW flow will develop in the wake of weekend system with passing snow showers and colder temperatures expected for the start of next week.  Unfortunately, models have the bulk of the moisture driving south into Oregon / northern California with just spin off moisture for Washington.  

  

Forecast confidence: Good to fair.

Values from 4am today through 4am tomorrow.

Precipitation: Today 24hr water: 0  snow: 0 Tomorrow’s 24hr water: 0  snow: 0 Trend and Timing: No moisture expected.

Temperature: Low: 28  High: 38 Freezing level: Trend and Timing:    3000’ -5000’

Winds Base: 0-5 E Ridge Top:  0-10 E Trend and Timing: East flow will continue today with a switch to WNW tomorrow.