February 16, 2018

MOUNTAIN WEATHER FORECAST


Time and Day: 0630 Friday

The Snapshot:  A few days of sporty winter weather has begun.  Windy conditions with moderate snow today with heavy snow expected tomorrow.  Weekend snow totals could exceed 2’(yes feet).   Dry and very cold weather will start the new week.

The Science

Current Observations: This morning’s radar is lit up with widespread precipitation heading for the mountains.  It is snowing at Stevens Pass with .19” of water and 3” of new snow thus far.  The barometer is at 1017mb’s and falling.  The temperatures profile is 27base / 22 ridges with the westerly winds starting to crank up.

The Forecast: A strong low-pressure trough with two embedded warm fronts will bring heavy snow, fluctuating freezing levels and wind to Stevens Pass through early Sunday morning.  Snow totals by noon Sunday could exceed 3” of water/ +24” of snow. 

The Long Range:  The snow ends on Sunday.  A cold dry arctic air mass flowing in through the Frazer River Gap could produce the coldest temperatures of the year early next week.  

Weather Geek Speak:  The Frazer River outflow =  The Fraser River Valley is a large landform gap between the Coastal Mountains of BC and the Rocky Mountains in Central British Columbia.   When cold, dense air fills the interior basin from the north,  a big pressure difference occurs down the Fraser River gap, as a result cool, dry air pushes into the PNW.   


24hr values daily 4am to 4am.
Precipitation:
Today 24hr
water: .75-1  snow: 8-12

Tomorrow’s 24hr
water: 1-2  snow: 15-24

Trend and Timing:
Snow starts today and intensifies tomorrow.


Temperature:
Low:24     High: 32
Freezing level: 2500’-4000’ -3000’

Trend and Timing:   
Freezing levels will rise to 4000’ midday.  Freezing levels will then fall through the night to +-2500’.

 
Winds
Base:  5-15 W
Ridge Top: 10-20 W

Trend and Timing:
Strong consistent westerly winds will be a factor through the weekend.



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8:00am Start for Friday 3/29/2024 No ABS

 Warm and dry weather is on the way.