Issued: 7:16 AM PDT Wednesday, April 7, 2021
by Dennis D'Amico

Jump to: Weather Forecast I Snow Level I Precipitation I Ridgeline Winds I

Weather Synopsis

A Pacific frontal system dropping south from British Columbia will spread light precipitation and increasing cloud cover southward over the course of the day. Snow levels will drop rapidly into the 3000-4000' range with the onset of precipitation. Ridgeline winds will increase during the day as well. 

The main event will be tonight as the frontal boundary pushes through the Cascades between 12-2 am. After a burst of moderate precipitation, a Puget Sound convergence zone will form late tonight in the Hwy 2 and Mt Loop corridor and sag south towards I-90 into Thursday morning. This system looks like it will produce 4-12 inches of snow along the west slopes of the Cascades and Mt Hood with rapid cooling behind the front. There should be a significant spillover of snowfall downwind of the convergence zones for the east slopes near the Cascade crest.  Strong W-NW winds will develop overnight and continue through the morning hours. Expect showers to taper off Thursday morning and become scattered in the afternoon.  Cool cloudy conditions will persist through Thursday afternoon. 

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
Wednesday Light rain and snow developing this morning and becoming occasionally moderate in the afternoon. Increasing ridgeline winds.
Wednesday Night Moderate rain and snow becoming light to moderate showers after midnight. Strong ridgeline winds decreasing after midnight.
Wednesday Light rain and snow developing this morning and becoming light to moderate in the afternoon. Strong ridgeline winds.
Wednesday Night Moderate rain and snow becoming moderate showers after midnight. Strong ridgeline winds decreasing after midnight.
Wednesday Light rain and snow developing later this morning and becoming occasionally moderate in the afternoon. Increasing ridgeline winds.
Wednesday Night Moderate rain and snow becoming moderate showers after midnight. Strong ridgeline winds.
Wednesday Mostly sunny in the morning, becoming cloudy late morning. Light rain and snow developing in the afternoon. Increasing ridgeline winds.
Wednesday Night Light to moderate rain and snow becoming light to moderate showers after midnight. Heaviest precipitation Paradise area. Strong ridgeline winds.
Wednesday Cloudy in the morning. Light rain and snow developing late morning. Increasing ridgeline winds.
Wednesday Night Light to moderate rain and snow becoming moderate showers after midnight. Strong ridgeline winds.
Wednesday Cloudy in the morning. Light rain and snow developing mid-day. Increasing ridgeline winds.
Wednesday Night Light to moderate rain and snow becoming moderate showers after midnight. Strong ridgeline winds.
Wednesday Cloudy in the morning. Light rain and snow developing late morning. Increasing ridgeline winds.
Wednesday Night Light to occasionally moderate rain and snow becoming showers after midnight. Strong ridgeline winds decreasing after midnight.
Wednesday Mostly cloudy in the morning. Light rain and snow developing mid-day. Increasing ridgeline winds.
Wednesday Night Light to occasionally moderate rain and snow becoming showers after midnight. Heaviest showers near the Cascade crest. Strong ridgeline winds.
Wednesday Mostly sunny in the morning, becoming cloudy late morning. Light rain and snow developing in the late afternoon. Increasing ridgeline winds.
Wednesday Night Light to occasionally moderate rain and snow becoming light showers after midnight. Strong ridgeline winds.
Wednesday Mostly sunny in the morning, becoming cloudy in the afternoon. Chance of light rain and snow late. Strong ridgeline winds.
Wednesday Night Light to moderate rain and snow becoming moderate showers late. Strong ridgeline winds.

Precipitation (in)

Wednesday Wednesday Night Thursday
5 am - 5 pm 5 pm - 5 am 5 am - 5 pm
Hurricane Ridge LT 0.25 0.25 - 0.50 LT 0.10
Mt Baker Ski Area 0.50 0.50 - 0.75 LT 0.25
Mt. Loop - Barlow Pass 0.25 0.75 0.25
Stevens Pass LT 0.25 0.50 - 0.75 LT 0.25
Snoqualmie Pass LT 0.25 0.50 - 0.75 0.25 - 0.50
Crystal Mt LT 0.10 0.25 LT 0.10
Paradise LT 0.10 0.75 LT 0.25
White Pass LT 0.10 0.50 LT 0.10
Washington Pass LT 0.10 0.25 LT 0.10
Mission Ridge 0 LT 0.10 0
Salmon la Sac - Gallagher Head LT 0.10 0.25 - 0.50 0.25
Tieton River - Darland Mt. 0 LT 0.25 LT 0.10
Mt Hood Meadows 0 0.50 LT 0.25
Timberline 0 0.50 - 0.75 0.25
Hurricane Ridge Precipitation (in)
Wednesday LT 0.25
Wednesday Night 0.25 - 0.50
Thursday LT 0.10
Mt Baker Ski Area Precipitation (in)
Wednesday 0.50
Wednesday Night 0.50 - 0.75
Thursday LT 0.25
Mt. Loop - Barlow Pass Precipitation (in)
Wednesday 0.25
Wednesday Night 0.75
Thursday 0.25
Stevens Pass Precipitation (in)
Wednesday LT 0.25
Wednesday Night 0.50 - 0.75
Thursday LT 0.25
Snoqualmie Pass Precipitation (in)
Wednesday LT 0.25
Wednesday Night 0.50 - 0.75
Thursday 0.25 - 0.50
Crystal Mt Precipitation (in)
Wednesday LT 0.10
Wednesday Night 0.25
Thursday LT 0.10
Paradise Precipitation (in)
Wednesday LT 0.10
Wednesday Night 0.75
Thursday LT 0.25
White Pass Precipitation (in)
Wednesday LT 0.10
Wednesday Night 0.50
Thursday LT 0.10
Washington Pass Precipitation (in)
Wednesday LT 0.10
Wednesday Night 0.25
Thursday LT 0.10
Mission Ridge Precipitation (in)
Wednesday 0
Wednesday Night LT 0.10
Thursday 0
Salmon la Sac - Gallagher Head Precipitation (in)
Wednesday LT 0.10
Wednesday Night 0.25 - 0.50
Thursday 0.25
Tieton River - Darland Mt. Precipitation (in)
Wednesday 0
Wednesday Night LT 0.25
Thursday LT 0.10
Mt Hood Meadows Precipitation (in)
Wednesday 0
Wednesday Night 0.50
Thursday LT 0.25
Timberline Precipitation (in)
Wednesday 0
Wednesday Night 0.50 - 0.75
Thursday 0.25

Snow Level (ft)

Wednesday Morning Wednesday Afternoon Wednesday Evening Wednesday Night Thursday Morning Thursday Afternoon
Olympics 3500' 3000' 2500' 2000' 2000' 3000'
West North 3500' 3000' 2500' 2000' 2000' 3000'
West Central 4000' 3000' 2500' 2000' 2000' 3000'
West South 5000' 4000' 3500' 2500' 2000' 3500'
Stevens Pass 4500' 3500' 3000' 2000' 2000' 3000'
Snoqualmie Pass 4500' 3500' 3000' 2000' 2000' 3000'
East North 5000' 3500' 3500' 2000' 2500' 3500'
East Central 6000' 3500' 3500' 2500' 2500' 3500'
East South 6000' 4000' 3500' 2500' 3000' 3500'
Mt. Hood 7000' 4000' 4000' 3500' 3000' 3500'
Olympics Elevation
Wednesday Morning 3500'
Wednesday Afternoon 3000'
Wednesday Evening 2500'
Wednesday Night 2000'
Thursday Morning 2000'
Thursday Afternoon 3000'
West North Elevation
Wednesday Morning 3500'
Wednesday Afternoon 3000'
Wednesday Evening 2500'
Wednesday Night 2000'
Thursday Morning 2000'
Thursday Afternoon 3000'
West Central Elevation
Wednesday Morning 4000'
Wednesday Afternoon 3000'
Wednesday Evening 2500'
Wednesday Night 2000'
Thursday Morning 2000'
Thursday Afternoon 3000'
West South Elevation
Wednesday Morning 5000'
Wednesday Afternoon 4000'
Wednesday Evening 3500'
Wednesday Night 2500'
Thursday Morning 2000'
Thursday Afternoon 3500'
Stevens Pass Elevation
Wednesday Morning 4500'
Wednesday Afternoon 3500'
Wednesday Evening 3000'
Wednesday Night 2000'
Thursday Morning 2000'
Thursday Afternoon 3000'
Snoqualmie Pass Elevation
Wednesday Morning 4500'
Wednesday Afternoon 3500'
Wednesday Evening 3000'
Wednesday Night 2000'
Thursday Morning 2000'
Thursday Afternoon 3000'
East North Elevation
Wednesday Morning 5000'
Wednesday Afternoon 3500'
Wednesday Evening 3500'
Wednesday Night 2000'
Thursday Morning 2500'
Thursday Afternoon 3500'
East Central Elevation
Wednesday Morning 6000'
Wednesday Afternoon 3500'
Wednesday Evening 3500'
Wednesday Night 2500'
Thursday Morning 2500'
Thursday Afternoon 3500'
East South Elevation
Wednesday Morning 6000'
Wednesday Afternoon 4000'
Wednesday Evening 3500'
Wednesday Night 2500'
Thursday Morning 3000'
Thursday Afternoon 3500'
Mt. Hood Elevation
Wednesday Morning 7000'
Wednesday Afternoon 4000'
Wednesday Evening 4000'
Wednesday Night 3500'
Thursday Morning 3000'
Thursday Afternoon 3500'

5000' Temperatures (°F)

Wednesday Wednesday Night
Max / Min Max / Min
Olympics 31 / 28 26 / 19
West North 30 / 28 26 / 21
West Central 32 / 27 27 / 20
West South 32 / 29 28 / 21
Stevens Pass 32 / 27 28 / 20
Snoqualmie Pass 32 / 26 27 / 20
East North 32 / 28 29 / 19
East Central 32 / 30 29 / 20
East South 34 / 32 30 / 20
Mt. Hood 37 / 32 29 / 24
Olympics 5000' Temperature Forecast
(Max / Min)
Wednesday 5am - 5pm 31 / 28
Wednesday 5pm - 5am 26 / 19
West North 5000' Temperature Forecast
(Max / Min)
Wednesday 5am - 5pm 30 / 28
Wednesday 5pm - 5am 26 / 21
West Central 5000' Temperature Forecast
(Max / Min)
Wednesday 5am - 5pm 32 / 27
Wednesday 5pm - 5am 27 / 20
West South 5000' Temperature Forecast
(Max / Min)
Wednesday 5am - 5pm 32 / 29
Wednesday 5pm - 5am 28 / 21
Stevens Pass 5000' Temperature Forecast
(Max / Min)
Wednesday 5am - 5pm 32 / 27
Wednesday 5pm - 5am 28 / 20
Snoqualmie Pass 5000' Temperature Forecast
(Max / Min)
Wednesday 5am - 5pm 32 / 26
Wednesday 5pm - 5am 27 / 20
East North 5000' Temperature Forecast
(Max / Min)
Wednesday 5am - 5pm 32 / 28
Wednesday 5pm - 5am 29 / 19
East Central 5000' Temperature Forecast
(Max / Min)
Wednesday 5am - 5pm 32 / 30
Wednesday 5pm - 5am 29 / 20
East South 5000' Temperature Forecast
(Max / Min)
Wednesday 5am - 5pm 34 / 32
Wednesday 5pm - 5am 30 / 20
Mt. Hood 5000' Temperature Forecast
(Max / Min)
Wednesday 5am - 5pm 37 / 32
Wednesday 5pm - 5am 29 / 24

Ridgeline Winds (mph)

Wednesday Morning Wednesday Afternoon Wednesday Evening Wednesday Night
Olympics SW 10-20 SW 15-25 WSW 20-30 WNW 15-25
West North SSW 20-30 SSW 25-35 SW 25-35 W 15-25
West Central SW 15-25 WSW 20-30 WSW 25-35 W 20-30
West South WSW 15-25 WSW 20-30 WSW 30-40 W 30-40
Stevens Pass WSW 10-20 WSW 15-25 WSW 20-30 W 15-25
Snoqualmie Pass WSW 15-25 WSW 20-30 WSW 25-35 W 30-40
East North WSW 15-25 WSW 20-30 WSW 20-30 W 15-25
East Central WSW 15-25 WSW 25-35 W 30-40 W 30-40
East South W 10-20 W 15-25 W 20-30 W 20-30
Mt. Hood WSW 20-30 WSW 20-30 WSW 30-40 W 35-50
Olympics Ridgeline Winds (mph)
Wednesday Morning SW 10-20
Wednesday Afternoon SW 15-25
Wednesday Evening WSW 20-30
Wednesday Night WNW 15-25
West North Ridgeline Winds (mph)
Wednesday Morning SSW 20-30
Wednesday Afternoon SSW 25-35
Wednesday Evening SW 25-35
Wednesday Night W 15-25
West Central Ridgeline Winds (mph)
Wednesday Morning SW 15-25
Wednesday Afternoon WSW 20-30
Wednesday Evening WSW 25-35
Wednesday Night W 20-30
West South Ridgeline Winds (mph)
Wednesday Morning WSW 15-25
Wednesday Afternoon WSW 20-30
Wednesday Evening WSW 30-40
Wednesday Night W 30-40
Stevens Pass Ridgeline Winds (mph)
Wednesday Morning WSW 10-20
Wednesday Afternoon WSW 15-25
Wednesday Evening WSW 20-30
Wednesday Night W 15-25
Snoqualmie Pass Ridgeline Winds (mph)
Wednesday Morning WSW 15-25
Wednesday Afternoon WSW 20-30
Wednesday Evening WSW 25-35
Wednesday Night W 30-40
East North Ridgeline Winds (mph)
Wednesday Morning WSW 15-25
Wednesday Afternoon WSW 20-30
Wednesday Evening WSW 20-30
Wednesday Night W 15-25
East Central Ridgeline Winds (mph)
Wednesday Morning WSW 15-25
Wednesday Afternoon WSW 25-35
Wednesday Evening W 30-40
Wednesday Night W 30-40
East South Ridgeline Winds (mph)
Wednesday Morning W 10-20
Wednesday Afternoon W 15-25
Wednesday Evening W 20-30
Wednesday Night W 20-30
Mt. Hood Ridgeline Winds (mph)
Wednesday Morning WSW 20-30
Wednesday Afternoon WSW 20-30
Wednesday Evening WSW 30-40
Wednesday Night W 35-50

Jump to: Weather Forecast I Snow Level I Precipitation I Ridgeline Winds I

Previous forecast from Apr 6, 2021

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).

The label LT, is shorthand for ‘less than’.

Updated Mountain Weather Zone Name Changes – December 2020