January 5, 2018

MOUNTAIN WEATHER FORECAST

Time and Day:  0630 Friday

The Snapshot: Today there will be light rain, and dare I say, sleet. The good news is that the precipitation will change to snow overnight.  The snow will diminish tomorrow with more snow anticipated on Sunday/Monday. 

The Science

Current Observations: It is cloudy with light rain falling.  Temperatures are still inverted but warmer; 28f base, 32f on top.  The barometer has dropped to 1017mbs. The winds are light and easterly.  As anticipated, warm, moist, southerly flow aloft has moved in with light precipitation. 

The Forecast:   A cold front, about 100 miles offshore, will track toward the PNW today.  The warm airmass out ahead of the front will keep light rain/sleet falling at Stevens Pass through most of the day.  The cold front is timing out to pass east the Cascade Crest late tonight or early tomorrow morning.  Once that happens, the rain will shift to snow, the winds turn westerly and the temperatures will drop.   Therefore, expect a short period of snow for tomorrow’s opening.  

A high pressure ridge between storms will diminish the precipitation tomorrow afternoon with partial clearing through the night.   A warm front, previously expected on Monday, has advanced its arrival for Sunday.   This storm will start out as snow and possibly shift to mixed snow/rain sometime on Monday.     

The Long Range:  An active weather pattern will persist next week with several systems expected throughout.  Temperatures are expected to cool midweek so hopefully, this will mean mostly snow.   Stay tuned.
    
24hr Precipitation ending at 4 a.m:
Today 24hr water:.5   snow: 2-5
Tomorrow’s 24hr water: .25  snow: 1-3

Trend and Timing:
Light rain today shifting to snow around midnight tonight.  Snow tapers off tomorrow.


24hr temperature ending at 4 a.m: 
Low:26     High: 34
Freezing level: 5000’ – 3500’

Trend and Timing:   
Freezing levels will peak today and then drop in the wake of the cold front tonight.

 
24hr Winds (mph) ending at 4 a.m:
Base: 0-5 E shifting W
Ridge Top: 5-10 ESE  shifting W

Trend and Timing:
The east flow will shift westerly after midnight tonight.  Wind will be westerly and gusty tomorrow morning.


jM

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