A weak stationary front is stalled somewhere over southern Washington as of Wednesday morning. The front lacks moisture but continues to separate seasonably cool air over northern Washington State, relative to mild air in the Mt. Hood area. Expect mostly cloudy skies across the region today as mid-level clouds stream in from the west ahead of a pair of merging weak low-pressure centers. The lows should add enough moisture to the stalled frontal boundary Wednesday night to develop increasing light rain and snow across Washington State. The snow will expand northward and southward, peaking Thursday morning before the low tracks south off the Oregon coast and removes the weak dynamic support for the precipitation. We expect 2-5" of snow in the Mt. Rainier area with 0-2" in other areas. As the low approaches, low-level winds should shift E, ushering cooler air from the interior through the mountain gaps. Overall, Wednesday, Wednesday night, and Thursday will represent a gradual cooling trend throughout the region.
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
Wednesday
Mostly cloudy with gradually thickening mid-level clouds.
Wednesday
Night
Cloudy with a slight chance of very light rain or snow after midnight.
Wednesday
Mostly cloudy with gradually thickening mid-level clouds.
Wednesday
Night
Mostly cloudy.
Wednesday
Mostly cloudy with gradually thickening mid-level clouds.
Wednesday
Night
Mostly cloudy, then becoming cloudy.
Wednesday
Mostly cloudy with gradually thickening mid-level clouds.
Wednesday
Night
Light rain and snow developing during the evening and increasing after midnight.
Wednesday
Mostly cloudy with gradually thickening mid-level clouds. Light and variable winds at pass level.
Wednesday
Night
Cloudy with very light rain and snow developing in the early morning hours. Light E winds at pass level.
Wednesday
Mostly cloudy with gradually thickening mid-level clouds. Light and variable winds at pass level.
Wednesday
Night
Cloudy with very light rain and snow developing in the early morning hours. Increasing light E winds at pass level.
Wednesday
Mostly cloudy with gradually thickening mid-level clouds.
Wednesday
Night
Mostly cloudy.
Wednesday
Mostly cloudy with gradually thickening mid-level clouds.
Wednesday
Night
Cloudy with very light rain and snow developing in the early morning hours.
Wednesday
Mostly cloudy with gradually thickening mid-level clouds.
Wednesday
Night
Light rain and snow developing during the evening and increasing after midnight.
Wednesday
Mostly cloudy with gradually thickening mid-level clouds.
Wednesday
Night
Cloudy with very light rain and snow developing in the early morning hours.
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).