We're in for another hot one today following another mild night. Widespread above freezing overnight lows at mountain stations in the NWAC network ranged from the 30s to low 50s. The quasi-stationary strong upper level ridge that has been parked over the region for several days will begin to weaken today, squeezed between two weather systems. The first is a shortwave trough moving south along the Canadian front range today.
This upper level feature will keep precipitation to our east but bring some mid-level clouds near and east of the crest tonight along with a burst of moderate to even strong NW winds. Winds should be strongest further east of the crest for places like Mission Ridge. This will also cause freezing levels to dip this afternoon over the Washington Cascades. Mid-mountain temperatures will still be quite warm with widespread 50s and 60s, but should be a notch cooler than yesterday.
The second weather feature will be a very weak Pacific frontal system. This feature may spread increasing clouds over the Olympic peninsula tomorrow with scattered mid-level clouds over the Cascades. Freezing levels will drop into the 7000-8000' range tomorrow.
Weather station outage: The phone lines are down at our office and are affecting about 25% of our weather stations. We are working on the communication disruption and hope to have the stations back online soon.
Spring Schedule: This is the last 7 am Mountain Weather Forecast for the 2020-2021 season. The 230 pm Mountain Weather Forecast will continue daily through Sunday, May 2nd. Thanks for a great La Nina season!
Weather Forecast
Olympics
West North
West Central
West South
Stevens Pass
Snoqualmie Pass
East North
East Central
East South
Mt. Hood
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Sunday
Sunny.
Sunday
Night
Mostly clear.
Sunday
Mostly sunny. A few thin high clouds.
Sunday
Night
Mostly clear.
Sunday
Mostly sunny. A few thin high clouds. Ridgeline winds becoming moderate in the afternoon.
Sunday
Night
Mostly clear. Moderate ridgeline winds decreasing after midnight.
Sunday
Mostly sunny. Ridgeline winds becoming moderate in the afternoon.
Sunday
Night
Mostly clear. Moderate ridgeline winds decreasing after midnight.
Sunday
Mostly sunny. A few thin high clouds. Ridgeline winds becoming moderate in the afternoon.
Sunday
Night
Becoming partly cloudy after midnight. Moderate ridgeline winds decreasing after midnight.
Sunday
Mostly sunny. Moderate ridgeline winds.
Sunday
Night
Becoming partly cloudy after midnight. Moderate ridgeline winds decreasing after midnight.
Sunday
Mostly sunny with periods of high clouds. Ridgeline winds becoming moderate in the afternoon.
Sunday
Night
Partly cloudy. Moderate to strong ridgeline winds decreasing after midnight.
Sunday
Mostly sunny. A few thin high clouds. Moderate ridgeline winds.
Sunday
Night
Becoming partly cloudy after midnight. Moderate to strong ridgeline winds.
Sunday
Mostly sunny. A few thin high clouds. Ridgeline winds becoming moderate in the afternoon.
Sunday
Night
Becoming partly cloudy after midnight. Moderate to strong ridgeline winds.
Sunday
Mostly sunny. Ridgeline winds becoming moderate in the afternoon.
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).