A ridge of high pressure maintains dry weather Tuesday through Wednesday. Tuesday morning started on the chilly side in valley and lower-elevation mountain locales where weak inversions formed under light winds and clear skies. Ample sunshine on Tuesday should help the inversion to mix out by around 10 AM. Freezing levels should reach around 4000-5500 ft Tuesday afternoon. Winds remain light throughout the day. Thin, high clouds over western Washington may gradually spread east during the day, creating some filtered sunshine.
The high-pressure ridge axis shifts east of the region Tuesday night, spawning some light E flow through the mountain gaps which should gradually increase through Wednesday. Temperatures should be milder than Monday night. Periods of thin, high clouds will continue across the region.
Wednesday should be slightly milder than Tuesday with freezing levels reaching 5000-6000 ft. After a mostly sunny start, mid and high-level clouds gradually increase throughout the day ahead of a system arriving on Thursday.
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
Tuesday
Thin, high clouds and filtered sunshine.
Tuesday
Night
Thin, high clouds thickening slightly toward morning.
Tuesday
Mostly sunny with some thin, high clouds and filtered sunshine.
Tuesday
Night
Mostly clear with periods of thin, high clouds.
Tuesday
Mostly sunny with some thin, high clouds and filtered sunshine.
Tuesday
Night
Mostly clear with periods of thin, high clouds.
Tuesday
Mostly sunny with some thin, high clouds and filtered sunshine.
Tuesday
Night
Mostly clear with periods of thin, high clouds.
Tuesday
Mostly sunny with some thin, high clouds and filtered sunshine. Light W wind at the Pass.
Tuesday
Night
Mostly clear with periods of thin, high clouds. Light W wind switching E during the evening hours at the Pass.
Tuesday
Mostly sunny with increasing thin, high clouds and filtered sunshine. Light W wind at the Pass.
Tuesday
Night
Mostly clear with periods of thin, high clouds. Light W wind switching E during the evening hours at the Pass.
Tuesday
Mostly sunny with some thin, high clouds and filtered sunshine.
Tuesday
Night
Mostly clear with periods of thin, high clouds.
Tuesday
Mostly sunny with increasing thin, high clouds and filtered sunshine.
Tuesday
Night
Mostly clear with periods of thin, high clouds.
Tuesday
Mostly sunny with increasing thin, high clouds and filtered sunshine.
Tuesday
Night
Mostly clear with periods of thin, high clouds.
Tuesday
Mostly sunny with increasing thin, high clouds and filtered sunshine.
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).