9:50 AM fixed an error in the Hurricane Ridge precipitation forecast for Wednesday.
A cool trough transitions to a weak ridge on Tuesday. Temperatures dropped into the 10s and low 20s in many areas early Tuesday morning and should remain below seasonal norms throughout the forecast period but will gradually increase. Generally light snow showers activity is becoming increasingly isolated as it continues to decrease Tuesday morning, along with a weakening convergence around Stevens Pass. Despite increased atmospheric stability, expect some weak instability snow showers driven by daytime heating in the afternoon. Snow levels should rise from around 500-1000 ft in the morning to 2000-2500 ft in the afternoon.
A few snow showers could continue from Snoqualmie Pass to Mt Hood Tuesday evening, but expect precipitation to cut off overnight.
A warm front lifts northward ahead of the next system Wednesday morning with low-level E flow increasing throughout the day. Light snow initially develops along the E slopes of the Cascades, with light snow spreading to most areas later in the day. This system could bring impactful E winds to the passes and S winds to the Mt Baker area in the afternoon.
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
Tuesday
Partly cloudy with an isolated snow flurry.
Tuesday
Night
Mostly cloudy with isolated snow flurries.
Tuesday
Light snow showers in the morning become isolated from mid-day onwards.
Tuesday
Night
Mostly cloudy with isolated snow flurries.
Tuesday
Partly to mostly cloudy with decreasing light snow showers. Convergence ended early in the southern part.
Tuesday
Night
Mostly cloudy with isolated snow flurries.
Tuesday
Mostly cloudy with isolated but locally intense snow showers.
Tuesday
Night
Mostly cloudy with very light snow showers in the evening hours.
Tuesday
Light convergence snow decreasing or ending by midmorning. Then isolated snow showers. Light ridgeline and W wind at the Pass.
Tuesday
Night
Partly cloudy with very light snow flurries in the evening hours. Decreasing light ridgeline winds. Light W winds shift E at the Pass overnight.
Tuesday
Mostly cloudy with isolated light snow showers, mainly in the afternoon. Light to moderate ridgeline and W wind at the Pass.
Tuesday
Night
Mostly cloudy with very light snow showers in the evening hours. Decreasing light ridgeline winds. Light W winds shift E at the Pass overnight.
Tuesday
Partly cloudy with isolated snow flurries. Light to moderate ridgeline winds.
Tuesday
Night
Partly cloudy.
Tuesday
Partly cloudy with isolated snow flurries. Light to moderate ridgeline winds.
Tuesday
Night
Partly cloudy.
Tuesday
Partly cloudy with isolated snow flurries. Light to moderate ridgeline winds.
Tuesday
Night
Partly cloudy.
Tuesday
Moderate snow showers become light from mid-morning onwards. Decreasing moderate ridgeline winds with strong gusts.
Tuesday
Night
A few snow showers early, then mostly cloudy skies.
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).