The mountains will enjoy a mostly sunny day with seasonable temperatures to close out the weekend. Our region is under dry northerly flow aloft with a high pressure ridge positioned well offshore. A few areas of low clouds in the West Central and Snoqualmie Pass zones will hang around this morning, but should transition to more sun than clouds by late morning. Near and north of Washington Pass, there will also be some low/mid clouds this morning along with a stiff northerly breeze at times.
We'll see a relatively mild overnight with high clouds increasing. Periods of high clouds will continue on Monday as a system upstream in NW flow approaches the area. Some areas west of the Cascade crest will see increasing low clouds late in the day.
A trough will dig over the area Monday night through Tuesday night with light to moderate snow developing in NW flow.
Weather Forecast
Olympics
West North
West Central
West South
Stevens Pass
Snoqualmie Pass
East North
East Central
East South
Mt. Hood
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Sunday
Mostly sunny. Valley low clouds and fog this morning.
Sunday
Night
Partly cloudy with periods of high clouds overnight.
Sunday
Mostly sunny. Valley low clouds and fog this morning.
Sunday
Night
Partly cloudy with periods of high clouds overnight.
Sunday
Partly cloudy with areas of low clouds this morning. Partly to mostly sunny this afternoon.
Sunday
Night
Partly cloudy with periods of high clouds overnight.
Sunday
Mostly sunny. Valley low clouds and fog this morning.
Sunday
Night
Partly cloudy with periods of high clouds overnight.
Sunday
Mostly sunny with areas of low clouds this morning. Light west winds at Pass level.
Sunday
Night
Partly cloudy with periods of high clouds overnight. Light west winds at Pass level.
Sunday
Partly cloudy with areas of low clouds this morning, especially near and west of the Pass. Partly to mostly sunny this afternoon. Light west winds at Pass level.
Sunday
Night
Partly cloudy with periods of high clouds overnight. Light west winds at Pass level.
Sunday
Partly cloudy this morning becoming mostly sunny. Moderate ridgeline winds.
Sunday
Night
Partly cloudy with periods of high clouds overnight.
Sunday
Mostly sunny. Valley low clouds and fog this morning.
Sunday
Night
Partly cloudy with periods of high clouds overnight.
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).