The last in a series of shortwave disturbances is already starting to impact the region this morning as precipitation lifts from south to north. With a similar flow pattern to storms this past weekend, look for this system to once again favor the volcanoes as well as locations along the east slopes of the Cascades. Places like Twisp, Leavenworth, Salmon la Sac, and Ahutanum Meadows could receive more precipitation than sites closer to the Cascade crest. The big story with today's storm will be the winds. Strong and gusty E-SE winds will develop for many locations this morning. This will be particularly true for the mountain passes, west-side valleys, and more wind-prone sites like Cyrstal Mt and Mt Hood. With temperatures a notch cooler today than yesterday, expect mostly snow at Pass levels, with periods of mixed precipitation near Snoqualmie Pass.
As we head into the evening hours, the system will continue to move north and focus the remainder of its energy on the Mt Baker area. Elsewhere, showers and wind speeds should decrease significantly throughout the night as our weather pattern starts to shift. A weak high-pressure ridge will begin to building over the Pacific Northwest on Tuesday. While the day may start cloudy and drippy, the region should dry out as we see a break in the weather. Right now, it doesn't look like the skies will totally clear during the day, but expect at least some patches of blue sky.
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
Monday
Rain and snow increasing during the day. Moderate to strong SE wind becoming SW .
Monday
Night
Rain and snow becoming showery overnight. Moderate SW winds.
Monday
Cloudy in the morning with rain and snow developing. Moderate SE winds becoming S.
Monday
Night
Rain and snow heaviest in the evening, becoming showery. Moderate to strong and gusty SSW winds decreasing slightly.
Monday
Cloudy with rain and snow developing in the morning. Moderate to strong SE winds decreasing and becoming S.
Monday
Night
Rain and snow showers in the evening. Moderate SW winds decreasing.
Monday
Rain and snow heaviest in the morning. Moderate to strong and gusty SE winds turning S and decreasing slightly in the afternoon.
Monday
Night
Rain and snow showers heaviest near the volcanoes Light to moderate SW winds decreasing.
Monday
Rain and snow developing in the morning. Moderate east flow at Pass level. Moderate E ridgetop winds becoming SE and decreasing slightly in the afternoon,
Monday
Night
Rain and snow, heaviest in the evening. Light east flow at Pass level. Ridgetop winds becoming light and variable.
Monday
Rain and snow developing in the morning. Moderate easterly flow at Pass level. Strong and gusty E ridgetop winds decreasing in the afternoon.
Monday
Night
Rain and snow heaviest in the evening. Light easterly flow at Pass level. Light SW ridgetop winds decreasing.
Monday
Cloudy with rain and snow developing during the day. Precipitation could be heavier in the eastern mountains and valleys near Twisp. Moderate SE winds decreasing slightly in the afternoon.
Monday
Night
Cloudy with rain and snow showers primarily in the evening. Light to moderate SW winds decreasing.
Monday
Cloudy with rain and snow developing during the morning. Precipitation could be heaviest near Leavenworth and Salmon la Sac. Moderate to strong and gusty SE winds decreasing slightly in the afternoon.
Monday
Night
Cloudy with rain and snow showers in the evening. Moderate W winds decreasing.
Monday
Rain and snow developing in the morning. Precipitation heaviest near Ahtanum Meadows. Moderate to strong and gusty SE winds decreasing in the afternoon.
Monday
Night
Rain and snow showers in the evening. Moderate SW winds decreasing overnight.
Monday
Rain and snow heaviest in the morning. Strong to very strong and gusty winds will create stormy conditions. Winds should peak mid-day.
Monday
Night
Scattered rain and snow showers in the evening. Moderate SW winds decreasing.
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).