A January drought has been a relatively common occurrence for our region in recent years. The current iteration takes that pattern into hyperdrive, with an unusually powerful ridge of high pressure parked off our coastline through the weekend into the first half of next week.
With 10,000 to 12,500 ft freezing levels and light winds aloft through the weekend, the drivers of local weather are focused on subtle shifts in cold air pooled east of the Cascades. Easterly pressure gradients peaked Friday night and remain stronger than originally forecast into early Saturday. This has driven the shallow pool of cold air to slosh up against the east slopes of the Cascades, thickening it over the mountain slopes (and thinning it farther east, such as at Mission Ridge). The result is that the cold air pool is slightly stronger and slightly deeper than this time Friday morning. A secondary freezing level can generally be found below 4500 ft (5500-6000 ft at Washington Pass). The layer of cold air will be accompanied by a shallow layer of low clouds that get ushered into Snoqualmie, but not the higher passes, during the overnight and morning hours.
As easterly winds gradually ease Saturday through Sunday, expect the cold air pool thin and warm air to expand further into the middle elevations east of the Cascade Crest. Plan for a range of temperatures over short distances. Cold air should generally remain limited to lower elevations near and east of the Cascade Crest and passes. Once you ascend in elevation, expect warm, dry, cloud-free conditions.
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
Saturday
Sunny and warm.
Saturday
Night
Clear and mild.
Saturday
Sunny and warm.
Saturday
Night
Clear and mild.
Saturday
Sunny and warm.
Saturday
Night
Clear and mild.
Saturday
Sunny and warm. Moderate ridgeline winds are possible in areas near the Cascade Crest.
Saturday
Night
Clear and mild.
Saturday
Sunny. Warm at upper elevations, cooler at lower elevations. Mostly light ridgeline and E wind at the Pass.
Saturday
Night
Clear. Inversion conditions persist. Light ridgeline and E wind at the Pass.
Saturday
Sunny. Warm at upper elevations, cooler at lower elevations. Moderate ridgeline and light to moderate E wind at the Pass.
Saturday
Night
Clear. Inversion conditions persist. Light to moderate ridgeline and E wind at the Pass.
Saturday
Sunny. Warm at upper elevations with colder temperatures below.
Saturday
Night
Clear. Mild at upper elevations.
Saturday
Sunny. Warm at upper elevations with colder temperatures below.
Saturday
Night
Clear. Mild at upper elevations.
Saturday
Sunny. Warm at upper elevations with colder temperatures below.
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).