MOUNTAIN WEATHER FORECAST

Time and Day: 0630 Thursday

The Snapshot: Light snow today,  snow continuing tomorrow with the weekend trending dry.  

The Science:  Clouds are beginning roll in with lights snow starting to show up on radar.   Temperatures are inverted with the upper mountain be 8-10⁰ warmer.  This is due to the warmer air mass creeping up the western slopes of the mountains.  

Warm southwest flow ahead of an approaching cold front will bring snow to Stevens Pass today.  There may be a rain drop or two in the mix for a short period this afternoon as temperature advection occurs along the western slopes. Once the front moves through later this afternoon, temperatures will begin to fall; the snow will also turn to showers.  

A low-pressure trough will form tomorrow which is currently expected to head into the southeast portion of the state and then stall over Eastern Washington.  The bulk of the moisture will be concentrated along the south and eastern slopes of the Cascades.  Stevens will get a bit of the moisture but not the main hit.   Cold air will also be pulled in from the north, lowering freezing levels heading into the weekend.  

The Long Range:  The moisture clears out Saturday as a split flow pattern emerges.  Cool NW flow will bring snow back to the conversation during the final week of the year.  

Precipitation Ending at 4am: Today 24hr water = .25 Snow = 2-4 Tomorrow’s 24hr water = .25  snow = 2-4 Trend and Timing: Very light snow showers this morning shifting to snow late this afternoon.  Lights snow will persist into Saturday morning.

24hr temperature ending at 4 am tomorrow:  Low: 22    High: 30 Freezing level: 4500’ – 3000’ Trend and Timing:    Temperatures will climb to near freezing today but with an overall cooling trend starting tonight.

24hr Winds (mph) ending at 4 am tomorrow: Base: 0-5 E shifting W Ridge Top:  0-10 SW Trend and Timing: Weak east flow at the surface with SW flow aloft will slowly shift westerly over the next 24hrs.  Winds will shift east to west and back again with the passing of these next few systems.

jM