Mountain Weather Forecast

Time and Day: 0710 Sunday

The Snapshot: Fair and mostly sunny Sunday, with increasing clouds in the afternoon. Moderate snow Monday with gradually warming temperatures.

The Science

Current Observations:  3” of snow fell by midmorning on Saturday, with no additional accumulation overnight. This morning the skies are clear, and winds are generally calm. It has cooled off nicely, with temperatures at 18 degrees across the mountain. The barometer has been rising over the past 24 hours as a transitory sector of high pressure approaches and is currently at 1011 millibars.

The Forecast:  Washington sits between two weather systems this morning, with yesterday’s low pressure drifting east and an approaching front in the Pacific. Most of Sunday will be calm with lots of sunshine. Clouds will increase late Sunday with light snow beginning after midnight. Accumulations look light by Monday morning.

The front arrives in NW flow on Monday, bringing moderate snow during the day. Upper level winds increase Monday night, enhancing orographic showers Monday night and Tuesday. Freezing levels rise Monday night and Tuesday but look to remain below Pass level. We should see decent snow accumulation from Monday morning thru Tuesday afternoon, in the 10-14” range.

The Long Range: A high pressure ridge forms in the Pacific midweek, with light moisture streaming over the top of it. Light rain/snow is possible Wednesday and Thursday with more seasonal freezing levels, e.g. 4-5,000’.

24hr values daily 4am to 4am.

Precipitation: Sunday’s   24hr water: .10    Snow: 1-2” Monday’s   24hr water: .75     Snow: 8+” Trend and Timing: Light snow after midnight on Sunday, moderate snow during the day Monday, increasing Tuesday morning.

Temperature: Low: 18   High: 32 Snow level: 2000’ Trend and Timing:    Cool air remains in place Sunday and Monday with midday warming.

Winds Base: W 0-5 Ridge Top: W 5-10, then SW 15-20 Trend and Timing: Light and variable winds during the day Sunday will increase late Sunday night and Monday morning.