Mountain Weather Forecast

Time and Day: 0715 Sunday

The Snapshot: Heavy rain, warm, and windy today. Light to moderate snow Monday.

The Science

  Current Observations:  1.14” of rain in the past 24 hours at the Schmidt Haus weather station. Temperatures have been around 34-38 degrees across the ski area. Radar shows heavy precipitation falling to our west, and indeed across the Washington Cascades. The water vapor satellite image nicely shows the tap of tropical moisture riding up and over an offshore high pressure ridge, and being directed into the forecast area by a low pressure system off the Southern BC coast.

The Forecast: As the low pressure system approaches and drives a front across the Cascades today, heavy precip will fall across the western half of the state with far less making it to the eastern half. A warm air mass is associated with this precip event and the unfortunate result is high freezing levels. Heavy rain and warm temperatures with gusty winds will occur during much of the daylight hours Sunday. The good news is that after the front passes cool air will filter in driven by WNW upper level flow. We should be able to squeeze a few inches of snow out of it by 4am Monday, with continued light snow showers and possibly a brief moderate shower during the day Monday.

The Long Range: The offshore ridge amplifies a bit on Tuesday, supporting continued WNW flow. Freezing levels should remain below Pass level with light snow showers Tuesday. Wednesday and Thursday look mostly dry with another system arriving Thursday afternoon.

24hr values daily 4am to 4am.

Precipitation: Sunday’s   24hr water: 1.5-2.0   snow: 1-3” Monday’s   24hr water: .5-.75    snow: 4-6” Trend and Timing: Precip changes to snow early Monday morning, light snow with brief moderate showers Monday.

Temperature: Low: 28    High: 40 Freezing level: 6500’-4000’ Trend and Timing:    Warm all day Sunday, with cooling early Monday morning.

Winds Base: W 10-15 Ridge Top: SSW 30-40 Trend and Timing: Winds will remain gusty at the ridgetops, easing somewhat overnight.