A reasonably strong warm frontal system has brought drastic temperature changes to the west slopes of the Cascades. 24 hours ago our region experienced some of the coldest temperatures we've experienced in years. This morning, temperatures west of the Cascades are up to 40F warmer. The NW-SE oriented frontal system brings the warm air over the top of the cold air at the surface such that mid-elevations are warming much more rapidly than below 4000 ft. This has created a widespread freezing rain event in the lowlands. Meanwhile, the deep cold pool east of the Cascades remains strong and should maintain very cold temperatures (below 0F) with moderate winds ushering that air through the mountain gaps to create dangerously cold wind chills. This should maintain mostly snowfall through the mountain gaps. However, Hurricane Ridge and areas further west may already be experiencing a wintry mix. The main band of precipitation lifts through the north Cascades with heavy snow through the morning hours. WSW winds behind the front will continue to bring in milder air and a wintry mix of shower activity.
These showers should continue with little change in temperatures overnight.
Saturday, a stronger system moves toward the Alaska Panhandle and will bring another round of increasingly heavy rain and snow. With less cold air in place across western Washington, wintry mixes are more likely in the mountain gaps and just east of the Cascade Crest. We expect a changeover from snow to a wintry mix or even rain with additional warming during the day on Saturday with many areas getting an inch or more of water equivalent.
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
Periods of light wintry mix, possibly changing to all rain.
Friday
Night
Cloudy with showers comprised of rain, snow or a wintry mix.
Friday
Heavy snow in the morning tapering to moderate snow showers. Snow may mix with or change to rain.
Friday
Night
Moderate rain and snow showers.
Friday
Moderate snow showers with rain, sleet, freezing rain, or rain showers possible in western parts of the area.
Friday
Night
Moderate rain and snow showers.
Friday
Moderate snow showers potentially changing to a wintry mix.
Friday
Night
Moderate snow showers or wintry mix.
Friday
Moderate snow becoming more showery. Moderate ridgeline and light to moderate E wind at the Pass.
Friday
Night
Moderate snow showers. Moderate ridgeline and light to moderate E wind at the Pass.
Friday
Moderate snow becoming more showery. Snow may mix with freezing rain, sleet, or rain west of the Pass. Moderate to strong ridgeline and moderate E wind at the Pass.
Friday
Night
Moderate snow showers. Snow may mix with freezing rain, sleet, or rain west of the Pass. Moderate ridgeline and E wind at the Pass.
Friday
Moderate to heavy now tapering to moderate snow showers.
Friday
Night
Moderate snow showers.
Friday
Decreasing moderate snow showers.
Friday
Night
Moderate snow showers.
Friday
Decreasing moderate snow showers.
Friday
Night
Light snow showers possibly mixing freezing rain, sleet, or rain in the western part.
Friday
Moderate snow, sleet, freezing rain, or rain showers. Moderate to occasionally strong ridgeline winds.
Friday
Night
Moderate snow, sleet, freezing rain, or rain showers.
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).