It's groundhog Day weather-wise as Thursday will be similar to yesterday with little change forecast through Friday morning. We're on the backside of a broad upper level trough stretching over much of the country. While the jet stream is positioned further north into British Columbia, strong W-NW winds will extend well south of the border, especially impacting the WA Cascades. West winds will increase with elevation. If you're planning to poke into the Alps on the highest peaks and volcanoes, be prepared for relentless blustery winds. Winds will be strongest along the eastern slopes of the Cascades, with extreme gusts at times, and all areas will see winds tick up a notch tonight into Friday morning.
Low clouds will continue to blow in roughly near and north of I-90, with a few inches of snow every 12 hrs for the western slopes of the Cascades in Whatcom down to Snohomish counties. Stevens and Snoqualmie will see some light snow at times as well. The light showers will fade out along with the low clouds the further south you move, eventually transitioning to mostly sunny skies south of the Columbia River. With the moisture being confined below 9000', expect the highest peaks and volcanoes to poke above the low clouds near and south of Hwy 2. Along the eastern slopes, cloudier conditions along with the chance of a shower are possible near the Crest, with generally clearer, drier conditons further eastward. Milder air will only really work into the far south WA Cascades and Mt Hood today, with another slight bump in temperatures and freezing levels tomorrow.
Weather Forecast
Olympics
West North
West Central
West South
Stevens Pass
Snoqualmie Pass
East North
East Central
East South
Mt. Hood
Use dropdown to select your zone
Thursday
Mostly cloudy with scattered light snow showers, showers heaviest western slopes of the Olympics. Moderate to occasionally strong ridgeline winds.
Thursday
Night
Mostly cloudy with scattered light snow showers, showers heaviest western slopes of the Olympics. Moderate to strong ridgeline winds.
Thursday
Cloudy with light to occasionally moderate rain and snow showers, heaviest western part of the zone. Moderate to occasionally strong ridgeline winds.
Thursday
Night
Cloudy with light to occasionally moderate rain and snow showers, heaviest western part of the zone. Moderate to occasionally strong ridgeline winds.
Thursday
Cloudy with light to occasionally moderate rain and snow showers, heaviest western part of the zone. Moderate to occasionally strong ridgeline winds.
Thursday
Night
Cloudy with light to occasionally moderate rain and snow showers, heaviest western part of the zone. Moderate to occasionally strong ridgeline winds.
Thursday
Mostly cloudy with a slight chance of a shower western part of the zone. Partly to mostly cloudy eastern part of the zone. Mostly sunny high on the volcanoes. Moderate to occasionally strong ridgeline winds.
Thursday
Night
Mostly cloudy with a slight chance of a shower western part of the zone. Partly to mostly cloudy eastern and far southern part of the zone. Mostly clear high on the volcanoes. Moderate to strong ridgeline winds.
Thursday
Cloudy with occasional light snow showers. Moderate to strong W ridgeline winds, moderate W at Pass level.
Thursday
Night
Cloudy with occasional light snow showers. Moderate to strong W ridgeline winds, moderate W at Pass level.
Thursday
Cloudy with occasional light snow showers. Moderate to strong W ridgeline winds, moderate W at Pass level.
Thursday
Night
Cloudy with occasional light snow showers. Moderate to strong W ridgeline winds, moderate W at Pass level.
Thursday
Cloudy with occasional light snow showers near the Cascade crest, mostly cloudy further east. Strong ridgeline winds.
Thursday
Night
Cloudy with occasional light snow showers near the Cascade crest, mostly cloudy further east. Strong to occasionally extreme ridgeline winds.
Thursday
Cloudy with occasional light snow showers near the Cascade crest, partly to mostly cloudy further east. Strong to occasionally extreme ridgeline winds.
Thursday
Night
Cloudy with occasional light snow showers near the Cascade crest, partly to mostly cloudy further east. Strong to extreme ridgeline winds.
Thursday
Mostly cloudy near the Cascade crest, partly to mostly sunny further east. Strong to occasionally extreme ridgeline winds.
Thursday
Night
Mostly cloudy near the Cascade crest, partly to mostly clear further east. Strong to extreme ridgeline winds.
Thursday
Mostly sunny. Moderate to occasionally strong ridgeline winds.
Thursday
Night
Mostly clear. Moderate to occasionally strong ridgeline winds.
The NWAC program is administered by the USDA-Forest Service and operates from the National Weather Service Forecast Office in Seattle. NWAC services are made possible by important collaboration and support from a wide variety of federal, state and private cooperators.
The 5000’ temperature forecast does not imply a trend over the 12 hr period and only represents the max and min temperatures within a 12 hr period in the zone. The 6-hr snow level forecast, the forecast discussion, and weather forecast sections may add detail regarding temperature trends.
The snow level forecast represents the general snow level over a 6 hr time period. Freezing levels are forecast when precipitation is not expected.
*Easterly or offshore flow is highlighted with an asterisk when we expect relatively cool east winds in the major Cascade Passes. Easterly flow will often lead to temperature inversions and is a key variable for forecasting precipitation type in the Cascade Passes. Strong easterly flow events can affect terrain on a more regional scale.
Ridgeline winds are the average wind speed and direction over a 6 hr time period.
The wind forecast represents an elevation range instead of a single elevation slice. The elevation range overlaps with the near and above treeline elevation bands in the avalanche forecast and differs per zone.
Wind direction indicates the direction the wind originates or comes from on the 16-point compass rose.
Water Equivalent (WE) is the liquid water equivalent of all precipitation types; rain, snow, ice pellets, etc., forecast to the hundredth of an inch at specific locations. To use WE as a proxy for snowfall amounts, start with a snow to water ratio of 10:1 (10 inches of snow = 1 inch WE). Temperatures at or near freezing will generally have a lower ratio (heavy wet snow) and very cold temperatures can have a much higher ratio (dry fluffy snow).