MOUNTAIN WEATHER FORECAST

Stevens Pass Mountain Weather Forecast

Friday 11/15/19 1000am

Current Observations:

24hr Precipitation:      .12” of rain, 0” of snow

Temperature profile:    33 base, 28 ridge

Pass level winds:          Light, easterly

Barometer:                 1014mbs and slowly falling

Sky:                             Overcast

Radar:   Bands of rain moving through the region with the leading edge of the approaching cold front making landfall.

The Forecast: Intermittent moderate rain showers today with pass level temperatures in the mid to upper 30’s .  Cooling tonight with light precipitation.   Another round of rain will begin tomorrow afternoon with rain continuing into Sunday morning.  No snow accumulation expected below 5000’.

Long Range:  Another storm will move through on Monday with a drying trend setting up for the remainder of the week.  No snow accumulation expected.

  

The Science:  A weakening cold front will move through the region today.  Once the front passes east of the crest, the winds will shift westerly with a short period of post frontal gusts likely.  The precipitation will break up in the wake of the front with freezing levels dropping to 5000’ or so.  

Warm air advection driven by southwest flow will push freezing levels into the 10,000’ range by Sunday.  Moderate to heavy moisture will accompany the warm SW flow. 

One more low pressure system will track through on Monday with more rain and high mountain snow.   Cool, dry air from the interior west will fill in behind this system with freezing levels possible dropping to around 2000’.  A dirty (unorganized) high pressure ridge will lean into the region as the week progresses with dry and seasonally average temperatures expected.

Confidence:  Good through the weekend, poor for long range.

Values from 4am today through 4am tomorrow.

Precipitation: Today 24hr water: .5 snow: trace on upper mountain Tomorrow’s 24hr water: .25-.5  snow: Trend and Timing: The moderate to heavy rain will slow diminish through the day with the next round of moisture entering the mountains tomorrow afternoon.

Temperature: Low: 32   High: 38 Freezing level: 6500’ – 5000’ - 6000’ Trend and Timing:    Freezing levels will fall to +-5000’ tonight and then rise above 7000’ tomorrow.

Winds Base: 0-5 E shifting W Ridge Top: 0-5 E shifting W  Gusty Trend and Timing: Winds will shift westerly today with a short period of gusty post front winds possible.  The flow pattern shifts SW over the weekend.