A cold, wintry, and active weather pattern prevails during the short term. A series of potent shortwaves progress rapidly through the region in succession.
The first continues to bring moderate to heavy snow to the region early Friday morning. The front passes through the Cascades by mid-morning, with ample instability to continue moderate to heavy snow. Precipitation will remain continuous in most locations but with embedded heavier convergence bands focusing on the central Cascades. Ridgeline winds also increase into the moderate range behind the front (strong for Mt Hood). With high (15:1) snowfall ratios, many trailhead locations can expect 6-12" of snowfall during the day.
Westerly post-frontal flow continues through the evening hours. Moderate ridgeline winds increase further overnight as the second shortwave frontal band approaches. Snowfall becomes heavy and steady in the early morning hours.
On Saturday, expect very heavy snowfall early in the day with a mid-morning frontal passage. Moderate to heavy post-frontal snow showers continue throughout the day with moderate ridgeline winds (strong at Mt Hood). As the front passes, expect a subtle bump in temperatures during the morning hours that could lead to a period of higher-density snow for Mt Hood.
Over the next 36 hours, expect most trailhead locations to pick up 1-3 ft of snow with the most at Paradise.
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
Moderate to occasionally heavy snow showers. Moderate ridgeline winds.
Moderate snow (heavy at Paradise). Moderate ridgeline winds.
Friday
Night
Increasing moderate to heavy snow (heaviest at Paradise). Increasing moderate ridgeline winds.
Friday
Moderate to heavy snow with afternoon convergence enhancement. Increasing light to moderate ridgeline winds. Light E wind switching W at the Pass by mid-morning.
Friday
Night
Increasing moderate to heavy snow. Increasing moderate ridgeline winds. Increasing light to moderate W wind at the Pass.
Friday
Moderate to heavy snow with afternoon convergence enhancement. Increasing light to moderate ridgeline winds. Light E wind switching W at the Pass by mid-morning.
Friday
Night
Increasing moderate to heavy snow. Increasing moderate ridgeline winds. Increasing light to moderate W wind at the Pass.
Friday
Increasing light to moderate snow. Light to occasionally moderate ridgeline winds.
Friday
Night
Increasing light to moderate snow. Increasing 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).