MOUNTAIN WEATHER FORECAST

Time and Day: 0930 Thursday

The Snapshot:  Snow shower will become more frequent this afternoon and begin to taper off tomorrow.  Friday night and Saturday will be mostly dry and cold.  There will be a chance of an additional inch or two of snow on Sunday.

Current observations: Broken clouds, temp = 32f, RH=94%, Barometer = 1004mb and dropping, wind 2-5mph WSW.

The Science:  The approaching cold front is weakening as it slowly drifts south.  Therefore, the precipitation amounts will be downgraded from yesterdays forecast.  Moderate snow showers will be pulled into the mountains as the system makes it way south through the day.      

Once the front moves by Stevens Pass sometime tonight, the precipitation will begin to dwindle.  A topographical weather feature known as the Frazer River Outflow (cold air flowing south through the gap between the BC Coastal Mountains and Canadian Rockies – The Frazer River) will kick in.  Freezing levels are expected to drop below 2000’ after midnight tonight.  Temperatures will remain unseasonably cold through the weekend.   

*Freeze warning -  water pipes that have little to no snow for insulation can freeze.

The Long Range:   A system will track through the southern half of the state on Sunday with just a bit of moisture making it to Stevens.  A ridge of high pressure will move in late Sunday evening for a dry start to the new week.  More active weather is on the docket for the middle of next week for more potential snow.     

24hr Precipitation ending at 4am: Today 24hr water: .5  snow: 3-6 Tomorrow’s 24hr water: .25  snow: 1-2 Trend and Timing: The heaviest period of snow will be between noon and 7 pm today.  Snow will shift to showers through the night and taper off tomorrow afternoon.

24hr temperature ending at 4 am:  Low: 20    High: 32 Freezing level: 4000’ -  1500’ Trend and Timing:    Temperatures will begin to fall today with lows reaching into the lower 20’s or even teens by tomorrow morning.

24hr Winds (mph) ending at 4 am: Base: 0-5 W shifting E Ridge Top: 5-10 W shifting E Trend and Timing: Winds will be westerly for most of the day and then begin to shift easterly overnight.  East flow will strengthen tomorrow.

jM