December 16, 2015

MOUNTAIN WEATHER FORECAST

Time and Day: 0630 Wednesday

The Snapshot:  Dry today with a good old PNW storm cycle starting tomorrow and lasting well into next week; plenty of snow on the way.

The Science:  The Northern Jetstream will take aim at the PNW, bringing with it, the next series of storms for the Cascade Mountains.  The action starts early tomorrow morning with arrival a warm front.  Cold air flowing in from the Canadian Rockies will set up a nice east flow situation; which means snow for Stevens Pass.  Freezing levels will briefly spike up to 5000’ with enhanced precipitation late Thursday night.  Hence, a short-lived shot of rain will be possible. A cold front quickly follows Friday morning, dropping temperatures and turning the precipitation to intermittent snow showers.   

Long Range:  Northwest flow will keep the storms rolling in through the weekend and likely into next week.  With the brief exception of tomorrow night, freezing levels appear to be in favor to produce mostly snow through this series of storms.    

Precipitation ending at 4 am:
Today’s 24hr Water =  <.25 ”   Snow =  1-3”

Tomorrow’s 24hr Water = 1”   Snow = 12-14”

Trend and Timing:
The main push of moisture is timing out to arrive around +- 4 am tomorrow morning.  Moderate snow is expected through the day.


24hr temperature ending at 4 am tomorrow: 
Low: 18  High: 26
Freezing level: 3000’ – 2000’.

Trends and Timing:
Cold east flow will keep surface temperature +-200f  through late tomorrow night. 

 
24hr Winds (mph) ending at 4 am tomorrow:
Base: 5-10 N shifting E
Ridge Top:  5-15 NE  shifting E

Trend and Timing:
Gusty northerly winds this morning will diminish and shift easterly through the day.  East flow strengthens tonight.



jM

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