Happy New Year from the Northwest Avalanche Center! We'll ring in 2023 with a pretty quiet weather pattern. High pressure will move over the area today leading to dry weather and moderate freezing levels/temperatures. There are a few isolated showers this morning for the northwest Cascades to near and west of Snoqualmie Pass, but those should quickly die down without significant impacts. Low clouds will start to break up today in most areas as high pressure starts to take control of our weather. The exceptions will be for the Mtn Loop/Hwy 20 W/542 corridors where low clouds are unlikely to fully scour.
Offshore flow and E-SE winds will begin to develop overnight. This should return low clouds to the major Cascade Passes, White, Stevens and Snoqualmie and low valleys along the east slopes. Colder air along the east slopes of the Cascades will also begin to seep over the Cascade crest on Monday as well, leading to a slight cooling trend. Areas further west of the Cascade crest like the Olympics and Mt Baker will see relatively milder freezing levels/temperatures. An approaching frontal system will weaken as it approaches the coast on Monday. Precipitation is unlikely to push inland, but high clouds will spread over the region starting early Monday.
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
Sunday
Partly cloudy with areas of low clouds this morning then becoming mostly sunny.
Sunday
Night
Mostly clear. High clouds increasing late.
Sunday
Partly to mostly cloudy with low clouds this morning becoming partly sunny this afternoon.
Sunday
Night
Partly cloudy. High clouds increasing late.
Sunday
Partly to mostly cloudy with low clouds this morning becoming partly sunny this afternoon.
Sunday
Night
Partly cloudy. High clouds increasing late.
Sunday
Partly cloudy with areas of low clouds this morning then becoming mostly sunny.
Sunday
Night
Mostly clear. High clouds increasing late.
Sunday
Mostly cloudy with low clouds this morning then becoming partly to mostly sunny. Light west winds at Pass level.
Sunday
Night
Partly cloudy in the evening, becoming cloudy after midnight. Light east winds at Pass level.
Sunday
Mostly cloudy with low clouds this morning then becoming partly to mostly sunny. Light west winds at Pass level.
Sunday
Night
Partly cloudy in the evening, becoming cloudy after midnight.Light east winds at Pass level.
Sunday
Partly cloudy with areas of low clouds this morning then becoming sunny.
Sunday
Night
Partly cloudy in the evening, becoming cloudy after midnight.
Sunday
Partly cloudy with areas of low clouds this morning then becoming sunny.
Sunday
Night
Partly cloudy in the evening, becoming cloudy after midnight.
Sunday
Partly cloudy with areas of low clouds this morning then becoming sunny.
Sunday
Night
Partly cloudy in the evening, becoming cloudy after midnight.
Sunday
Partly cloudy with areas of low clouds this morning then becoming sunny.
Sunday
Night
Partly cloudy in the evening, becoming cloudy after midnight.
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).