Mountain Weather Forecast

Time and Day:  0655 Monday

The Snapshot: Moderate snow today, turning heavy tonight and continuing Tuesday with warming temperatures and gusty winds.

The Science

Current Observations:  2” of new overnight, with temperatures remaining cool. It is currently 22 on the upper mountain and 27 in the base area. Winds are moderate from the west. It is cloudy and snowing lightly. The barometer edged up slightly overnight to 1016, and should begin dropping any minute.

The Forecast:  Pre-frontal moisture delivered the preliminary shot of lower density snow this morning. The main front is still offshore but will continue its march eastward during the daylight hours. Consistent precip rates (light-moderate) will continue during the day Monday, with intensities ramping up after 8pm. Moderate snow continues Monday night with gusty winds.

WNW upper flow will continue to pump moisture into the region on Tuesday, with heavy snow likely during the day Tuesday at warming temperatures. Snow level looks to remain below our Pass level on Tuesday, but Snoqualmie might be sad. The high pressure ridge in the eastern Pacific builds in amplitude Tuesday afternoon, cutting off moisture and ending the snow event Tuesday evening.

The Long Range: Wednesday looks dry and mild, with partly cloudy skies. The ridge retrogrades (flattens out) allowing NW flow to bring another system into northern Washington on Thursday. Most of the moisture appears to favor the northern half of the state, with light snow and clouds possible at Stevens Pass. Active weather is possible for next weekend.

24hr values daily 4am to 4am.

Precipitation: Monday’s   24hr water: .75-1.0    Snow: 10-12” Tuesday’s   24hr water: .75-1.0     Snow: 8-10” Trend and Timing: Moderate snow during the day Monday, 4-6” likely during operations. Heavier snow Monday night and Tuesday morning, with heavy snow continuing during the day Tuesday. Snow ends Tuesday afternoon.

Temperature: Low: 22   High: 33 Snow level: 3500’ Trend and Timing:    Temperatures will creep up during the day and overnight lows will be higher than in recent days.

Winds Base: W 10-15 Ridge Top: WSW 20-35 Trend and Timing:   Winds will increase during the day Monday, remaining moderate-strong and gusty thru Tuesday morning.