MOUNTAIN WEATHER FORECAST

0700 Saturday:

The Snapshot:  The next 24-36 hrs will be sporty.  The snow is expected to change to rain later today and then back to snow tomorrow.  There will be a high wind advisory tonight and tomorrow as the Puget Sound Convergence Zone kicks into action.  

The Science:  A strong frontal boundary is entering the mountains this morning pushing heavy snow ahead of an approaching warm front.  High winds, rising freezing levels and heavy rain will accompany the front later today.  Tonight will be very wet with heavy rain; cold air arrives mid-morning tomorrow. With some luck and a long lasting convergence zone, there could be an additional foot of snow on the ground by Monday morning.  A high-pressure ridge forms off of the NW coast on Monday cutting off the moisture stream.  Thus, Monday will be dry and partly clear.

4-7day Long Range:  The weather pattern remains interesting as another warm front with mixed rain and snow moves through on Tuesday.  The interesting part is that models have a cut-off low forming along the US/Canadian border.  This has potential to bring cold air and moisture to the mountains late Tuesday and Wednesday for some potential measurable snow. The week will end dry and cold with some light snow possible over the weekend.  

Precipitation ending at 4am: Today’s 24hr Water = +2  Snow = 6-10 Tomorrow’s 24hr Water= +1  Snow = 6-12 Trend and Timing: Heavy snow is expected to change to rain by the end of the day.  Heavy rain tonight with  +2” possible.  Models differ on the amount of rain tonight – 2-5” spread.  Time will tell.  Rain turns back to snow tomorrow by noon or so.  Convergence conditions may keep the snow falling through early Monday morning.

24hr temperature ending at 4am tomorrow:  Low: 28   High: 42 Freezing level: 4000’   6500’ Trends and Timing: Freezing levels are expected to reach 5000’ by early afternoon.   Temperature will begin to slowly fall tomorrow morning with freezing levels dropping back to 4000’ late tomorrow night.

24hr Winds (mph) ending at 4am tomorrow: Base: 5-10 E shifting W Ridge Top:  5-10 E shifting W   Strong wind advisory tonight   Trend and Timing: East flow is expected to hang in there until late this afternoon.  Strong convergent westerly flow will kick in tonight.  +50mph winds can be expected along the ridge tops with 40mph winds in the base area tomorrow morning.  Winds will continue to be strong into early Monday morning.

JM