An upper-level trough is keeping temperatures cool on Wednesday morning. NWAC stations primarily recorded temperatures in the 20s at NWAC stations Tuesday night. A circulation center sits near the mouth of the Columbia River, with a N-S oriented cold front over the Willamette Valley.
On Wednesday, the circulation center and associated front continue to slowly track SE. The frontal passage should shut off moderate snow in the Mt. Hood area by around mid-morning. Lingering snow showers south of highway 2 in Washington should also end by around mid-morning as upper-level drying NNW flow moves in aloft. Skies cleared early in the North Cascades and that clearing trend should spread southward through the morning hours, yielding a cool, but pleasant Wednesday with sunshine making an appearance in most areas.
Wednesday night, clouds should increase ahead of an initial weak disturbance moving southward on NNW flow. Light to very light snow should develop for the mountains of northern Washington by the morning hours.
On Thursday, light to moderate snow increases for the mountains of Washington as NW flow aloft continues. Mt. Baker stands to pick up 5-8" of snow by the end of the day. W ridgeline winds should increase into the moderate range by Thursday afternoon from Snoqualmie Pass southward.
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
Wednesday
Mostly cloudy with weak upslope snow flurries possible for the northern edge of the Olympics. Becoming mostly sunny in the afternoon.
Wednesday
Night
Increasing clouds with a chance of light snow developing by morning.
Wednesday
Mostly sunny.
Wednesday
Night
Increasing clouds with light snow developing after midnight.
Wednesday
Mostly cloudy with light snow showers tapering off south of highway 2. Then becoming mostly sunny by mid-morning.
Wednesday
Night
Increasing clouds with light snow developing after midnight.
Wednesday
Partly cloudy with light snow showers ending during the morning hours, then becoming mostly sunny.
Wednesday
Night
Increasing clouds with very light snow possibly developing in the early morning hours.
Wednesday
Partly cloudy with light snow flurries ending early, then becoming mostly sunny. Light E pass-level winds switching W by the afternoon.
Wednesday
Night
Increasing clouds with very light snow developing after midnight. Light W winds at the Pass.
Wednesday
Decreasing bands of light snow, mainly west of the Pass proper, where low clouds may linger into the afternoon. Otherwise, becoming mostly sunny from mid-morning onwards. Light E pass-level winds switching W by the afternoon.
Wednesday
Night
Increasing clouds with light snow developing after midnight. Light W winds at the Pass.
Wednesday
Mostly sunny.
Wednesday
Night
Increasing clouds with very light snow developing around and west of the Washington Pass.
Wednesday
Partly cloudy early, then becoming mostly sunny.
Wednesday
Night
Increasing clouds with very light snow developing after midnight.
Wednesday
Partly cloudy with a chance of very light snow early in the day.
Wednesday
Night
Partly cloudy in the evening with increasing clouds after midnight.
Wednesday
Moderate snow tapering off around 10 AM. Then becoming partly cloudy.
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).