MOUNTAIN WEATHER FORECAST

0630 Sunday:

The Snapshot: Whew what a night – telemetry has a max gust of 50mph with close to 2” of rain.   The good news:  temperatures are descending; rain is turning back to snow on the upper mountain, and the wind will mellow later today. There is a potential for another foot or more of snow by tomorrow morning. Tomorrow will trend dry with mixed rain and snow again on Tuesday.  Snow for Christmas.     

The Science:  The warm front hit the mountains around 10pm last night and is now well east of us.  Cool air aloft is streaming in from the NW this morning; this will drop freezing levels to 4000’ by tonight.  The Puget Sound Convergence Zone has developed, so precipitation (hopefully mostly in the form of snow) will be steady through late tonight.   A weak high-pressure ridge will pass over the mountains tomorrow cutting off the moisture stream.  Another warm front, weaker than last nights, will bring rain below 4500’ and mixed rain and snow for the upper mountain on Tuesday. 

4-7day Long Range:  Another warm front followed by cool NW flow will occur on Tuesday/Wednesday.  So expect another round of rain changing to snow.   Hopefully, our luck will continue, and we will have another 6-10” of snow on the ground by Christmas day.  The weekend trends cool and dry as high pressure builds over the region.   Could there actually be a powder day on Christmas????

Precipitation ending at 4am: Today’s 24hr Water =1-1.25   Snow = 8-15” Tomorrow’s 24hr Water= <.25  Snow = 1-3 Trend and Timing: Heavy snow, above 4500’ with mix rain in the base area will continue until just after midnight tonight.  Light snow showers linger tomorrow morning with afternoon clearing.

24hr temperature ending at 4am tomorrow:  Low: 26   High: 32 Freezing level:  +-4000’ Trends and Timing: Freezing levels will fall to 4500’ this morning and drop to 4000’ tonight.  Freezing level rise above 5000’ again on Tuesday and then back down on Wednesday.  Yo-Yo.

24hr Winds (mph) ending at 4am tomorrow: Base: 5-15 W Ridge Top:  10-20 W gusty to 40 Trend and Timing: Strong westerly convergence winds will continue to blow through most of the day.  Winds weaken this afternoon and shift to light NW flow tomorrow.

JM