MOUNTAIN WEATHER FORECAST

Time and Day: 0900 Sunday 

The Snapshot:   Wind and heavy rain switching to snow this afternoon.  Heavy snow expected tonight.  A dry and clearing trend begins tomorrow afternoon.  

The Science: The expected warm front passed over the Cascade Crest early this morning.  The front pushed a nice patch of cool air ahead of it – hence the short period of snow.  Temperatures have now shot up in the wake of the front with heavy rain expected this morning.  The wind machine is also getting started again with strong westerly flow expected for most of the day.

THE GOOD NEWS:  The approaching cold front is charging in fast and should begin to mix in cooler air sooner than earlier models predicted.  Hopefully this will translate to less rain and more snow.   

SNOW: Once the cold front moves through, temperatures will sharply decline with heavy snow continuing through mid morning tomorrow.  The clouds will begin to thin and clear tomorrow afternoon.   Storm totals from noon today through noon tomorrow range between 1-2” of water and 12-24” of snow.

4-7day Long Range:  Cold arctic air arrives from the north on Tuesday with strong high pressure building over the PNW.   Expect well below average temperatures and dry weather to carry out the week.  Low temperatures could dip into the single digits with highs touching the low 20’s.

 

Precipitation:   Water by 4am = +1” Snow equivalent =  12+   Total inches of water by noon tomorrow = 1.25+ Total inches of snow by noon tomorrow = 12-15   Trend and Timing:   The rain is expected to switch to snow above Hogsback around noon today.  Snow level will fall through the day with snow base area by late this afternoon.  Snow totals could be higher depending on how long the Convergence Zone remains intact.   Snow is expected to taper off by noon or so tomorrow.

Base Temp and Freezing levels:                                        Low: 24   High: 40 Freezing level:  5000’       2000’   Trend and Timing:   Freezing levels will peak around 5500’ this morning.  Temperatures will then begin to fall with freezing levels reach 4000’ later today.  Temperatures will continue to fall to with freezing levels dropping below 500’ by Tuesday morning.

Wind (mph)   Base:  10-20 W Ridge Top: 15-30 W gust to 40   Trend and Timing:   High winds will continue to batter the ridges for most of the day.  Winds begin to diminish this evening and shift northerly tomorrow.