A warm frontal feature continues to slowly edge north over the region today and will hang up near the Canadian border while precipitation peters out for the central/south WA Cascades and Mt Hood area. SW winds aloft continue to push milder air near the Cascade crest, creating a wide range in temperatures and precipitation types. In general, areas west of the crest and above 5000' are milder with much colder air entrenched in the Passes and along the east slopes of the Cascades. Freezing rain has been reported along the lower slopes of Mt Hood, White Pass and the western Cascade foothills of I-90 and there's good reason to suspect that icing extends to similar areas. The Olympics and the Mt Baker area will see precipitation continue and since they're further west from the effects of cold easterly flow, will see a cleaner transition from snow to rain during the day. Moderate to locally strong S-SE ridgeline winds will decrease later this afternoon and overnight.
A strong ridge of high pressure will stay anchored over the inland NW over the weekend. This will keep weather systems offshore with occasional periods of showers rotating up later in the weekend. Friday night and Saturday look like a break day with a few showers possible for the Olympics and Mt Hood area. Despite the dry weather, there should be plenty of cloud cover over the region. Temperatures in the Passes and along the east slopes will slowly moderate over the weekend in this pattern as temperature inversions and low clouds persist.
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
Friday
Light to occasionally moderate rain and snow. Moderate to strong ridgeline winds.
Friday
Night
Scattered light rain and snow showers in the evening, then becoming cloudy.
Friday
Light to moderate rain and snow. Moderate to strong ridgeline winds.
Friday
Night
Scattered light rain and snow showers in the evening, then becoming cloudy.
Friday
Light to occasionally moderate rain and snow tapering off mid-day. Moderate ridgeline winds.
Friday
Night
Isolated light rain and snow showers in the evening, then becoming cloudy.
Friday
Light to occasionally moderate rain and snow. Moderate to strong ridgeline winds.
Friday
Night
Light to occasionally moderate rain, snow or freezing rain tapering off mid-day. Milder conditions western part of the zone, colder lower slopes and White Pass area. Moderate to strong ridgeline winds decreasing in the afternoon.
Friday
Light to occasionally moderate snow tapering off mid-day, then becoming mostly cloudy. Light to moderate E-SE ridgeline and Pass level winds.
Friday
Night
Cloudy. Light to moderate E-SE ridgeline and Pass level winds.
Friday
Light to occasionally moderate rain, snow and freezing rain near the summit and west tapering off mid-day, then becoming mostly cloudy. Moderate E-SE ridgeline and Pass level winds.
Friday
Night
Cloudy. Light to moderate E-SE ridgeline and Pass level winds.
Friday
Light to occasionally moderate snow tapering off mid-day, then becoming cloudy. Moderate ridgeline winds.
Friday
Night
Cloudy.
Friday
Light to occasionally moderate snow tapering off mid-day, then becoming cloudy. Moderate ridgeline winds.
Friday
Night
Cloudy.
Friday
Light to occasionally moderate snow tapering off mid-day, then becoming mostly cloudy. Moderate ridgeline winds.
Friday
Night
Cloudy.
Friday
Light rain, snow or freezing rain tapering off this morning, then becoming mostly cloudy. Moderate 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).