Mountain Weather Forecast

Weather Synopsis for Wednesday night through Sunday

A weak ridge of high pressure centered over the area Wednesday evening moves east overnight, allowing a warm front to clip the area in the early morning hours. The front appears better defined to our northwest, but still brings increasing southerly winds in the Olympics and Mt. Baker areas and possibly some light snow to the Mt. Baker area in the early morning hours as well. The most significant impact of the frontal passage will be the strong warming for Mt. Hood, the Olympics, and areas of Washington State west of the Cascade Crest overnight into Thursday morning. The temperature and associated pressure gradient set up over this same time frame should produce generally light but cooler E flow before winds switch westerly by late morning, allowing the warmer air spill through the passes and onto the east side of the Cascades.

As a trough digs offshore, it slows the approaching cold front, delaying the arrival of increasing light rain and snow to the Olympics until mid to late morning. Precipitation arrives at Mt. Baker in the afternoon. Southerly winds should be in the upper end of the moderate range gusting strong for much of the day. The front weakens as it drags ESE overnight, crossing the Mt. Baker area in the evening and then the rest of the Cascades in the early morning hours. It should bring light to moderate precipitation on a cooling trend. Mt. Baker and Paradise should receive the most precipitation. Snow levels lower from 4000-4500 ft with the onset of precipitation in the evening hours to Snoqualmie pass level by Friday morning.

Friday should be a somewhat drier day with periods of sun and clouds; the lingering frontal precipitation exits the East South Cascades and Mt. Hood area early while a trough in the nearshore waters spreads some light snow showers into the Olympics. Areas further west should be cooler Friday, while the warm air east of the Crest will be slower to depart.