Mountain Weather Forecast

Time and Day: 0730 Sunday

The Snapshot: Light snow in a weak cold front this afternoon, partly cloudy and dry Monday.

The Science: The persistent ridge that has been over the Pacific Northwest should begin to flatten a bit today, allowing a weak cold front in westerly flow aloft to cross the forecast area Sunday afternoon. Continued westerly flow Monday and Tuesday will bring very light snow showers, cooling temperatures, and partly sunny skies to North Central Washington.

The Long Range: Confidence in the formation of the Rex Block (high pressure over an offshore low) feature on Tuesday is high. However, its exact position is a little up in the air (sorry for the pun). Snowfall amounts have been significantly downgraded in the most recent model runs. Light snow looks possible for Tuesday and Wednesday at lower snow levels (~2,000’). Fortunately, this pattern looks to break down by Thursday/Friday, opening the door to more typical winter weather by next weekend.

Precipitation Ending at 4am: Today 24hr water = >.25 Snow = 1-3” Tomorrow’s 24hr water = >.10 Snow = 0-2” Trend and Timing: Light snow should begin Sunday afternoon, ending by 4am Monday morning. Light snow showers Monday afternoon.

24hr temperature ending at 4 am tomorrow:                                        Low:  20 (base area)   High: 42 (at upper weather stations) Freezing level: 8,000 – 3,500 Trend and Timing:    Temperatures and snow levels should drop throughout the day Sunday and further by Monday morning.

24hr Winds (mph) ending at 4 am tomorrow: Base: E 5-10, then W 5-10 Ridge Top: Variable, then W 10-20 Trend and Timing:  Increasing ridgetop winds during the day Sunday, peaking Sunday night and calming down by Monday morning. East winds thru the pass should ease by mid-afternoon Sunday, eroding the inversion. DV