A deep low pressure system passing inland this morning will pepper the region with strong to extreme winds and heavy showers today. The west slopes of the Cascades will end up with an additional 6-18" on top of what fell last night with lower amounts today for Mt Hood and for the far eastern slopes of the Cascades. Showers will be heaviest this morning and then become more focused on the central WA Cascades with a Puget Sound Convergence zone forming this afternoon and lasting through the evening. Forecast confidence has increased that this band of concentrated heavier showers will likely target the Mt Loop to Hwy 2 corridor. With strong west winds, expect significant spillover for higher snowfall totals for the central east slopes of the Cascades.
Snow levels will hover between 3000-4000'. When and if showers let up, even if it's been snowing to 3000' (or lower) expect those temperatures to bump up between significant precipitation breaks, especially in the afternoon.
And let's not forget the winds...westerly winds will be extreme near and south of I-90 to Mt Hood and merely strong near and north of Hwy 2 today. Strong winds will continue into the evening and then taper Tuesday night.
A ridge of high pressure will build in Tuesday night through Wednesday. Look for mild sunny conditions with the mildest temperatures along the west slopes of the Cascades, Mt Hood and cooler temperatures with inversions along the east slopes of the Cascades and Stevens Pass.
Radar note - the NWS western WA (Camano Island Radar) this morning.
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
Moderate to occasionally heavy rain and snow showers this morning, then mostly cloudy with scattered showers this afternoon. Strong to extreme winds easing somewhat this afternoon.
Tuesday
Night
Mostly cloudy with a chance of light rain and snow showers in the evening.
Tuesday
Moderate to heavy rain and snow showers this morning, then mostly cloudy with scattered showers this afternoon. Strong ridgeline winds.
Tuesday
Night
Mostly cloudy with a chance of light rain and snow showers in the evening.
Tuesday
Moderate to heavy rain and snow showers. Strong to extreme ridgeline winds.
Tuesday
Night
Mostly cloudy with a chance of light rain and snow showers in the evening.
Tuesday
Moderate to heavy rain and snow showers becoming lighter in the afternoon. Strong to extreme ridgeline winds.
Tuesday
Night
Light rain and snow showers in the evening taper off.
Tuesday
Moderate to heavy rain and snow showers. Strong W ridgeline and Pass level winds.
Tuesday
Night
Light rain and snow showers in the evening taper off. Light to moderate W ridgeline and Pass level winds.
Tuesday
Moderate to heavy rain and snow showers easing somewhat in the afternoon. Strong to extreme W ridgeline and Pass level winds.
Tuesday
Night
Light rain and snow showers in the evening taper off. Light to moderate W ridgeline and Pass level winds.
Tuesday
Moderate rain and snow showers, heaviest near the Cascade crest this morning, then scattered light showers in the afternoon. Strong ridgeline winds.
Tuesday
Night
Mostly cloudy with a chance of light rain and snow showers in the evening.
Tuesday
Moderate rain and snow showers, heavy near the Cascade crest. Strong ridgeline winds becoming extreme this afternoon.
Tuesday
Night
Mostly cloudy with a chance of light rain and snow showers in the evening.
Tuesday
Moderate rain and snow showers, heavy near the Cascade crest. Showers becoming lighter this afternoon and scattered. Strong ridgeline winds becoming extreme this afternoon.
Tuesday
Night
Mostly cloudy with a chance of light rain and snow showers in the evening.
Tuesday
Moderate rain and snow showers, becoming lighter and scattered this afternoon. Extreme ridgeline winds.
Tuesday
Night
Mostly cloudy with a chance of light rain and snow showers in the evening.
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).