Issued: 4:19 PM PDT Sunday, April 28, 2024
by Robert Hahn

Jump to: Weather Forecast I Precipitation I Snow Level I 5000' Temps I Ridgeline Winds I Extended Weather

Weather Synopsis

Although the NWAC weather forecast desk is winding down, the weather pattern hasn't received the memo. Some of the coolest temperatures of the spring will accompany unsettled weather into early next week.

A deep trough and associated low pressure center slide down the British Columbia coastline. WSW winds aloft will bring in this period of the most vigorous light to moderate showers rotating into the region ahead of the trough. Expect the heaviest precipitation in convergence shifting from the Skagit in the evening hours into the mountain loop area overnight. Already unseasonably low snow levels on Sunday continue to lower thorugh Sunday night and should be in the 2000-3000 ft range in the north and the 3000-4000 ft range in the south.

The first and coldest lobe of the trough reaches the coast early Monday and crosses the Cascades late morning. As the trough moves onshore, the precipitation eases somewhat for the northern Cascades, but expect a period of moderate to locally heavy snowfall for Mt Hood in the morning hours. Convergence potential shifts slightly further south with the potential targets from the Mountain loop to Snoqualmie Pass.  Snow levels should be in the 2000-3500 ft range. With cold air in place, the west slopes of the Cascades can expect up to a 30% chance of a thunderstorm in the mid-day or afternoon hours, with a slight chance further east.

The cold trough continues to bring mostly light showers to the same areas (moderate in Convergence locally in the central Washington Cascades) Monday night with 2500-3000 ft snow levels. On Tuesday the filling final lobe of the trough arrives. Expect most of the scattered (but locally intense) rain and snow shower activity to be south of I-90 with isolated showers further north.

The west slopes of the Cascades can expect 6-18" of low-density snowfall above the rain/snow line by the end of the day on Tuesday with up to 6" east of the Crest. Moderate ridgeline winds focus mostly on the mountain gaps and areas east of the Cascade Crest. These winds should decrease from north to south Sunday night through Monday night.

This April 28th, 2024 product is the final mountain weather forecast of the 2023-24 season. Thanks so much for joining us - from all of us at the weather forecast desk (Robert, Dennis, and Dallas).

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
Sunday Night Unseasonably cool with decreasing light rain and snow showers.
Monday Unseasonably cool with scattered to isolated rain and snow showers.
Sunday Night Unseasonably cool with moderate rain and snow showers in the evening becoming light overnight.
Monday Unseasonably cool with light rain and snow showers along with sun breaks at times.
Sunday Night Unseasonably cool with moderate rain and snow showers along with convergence bands. Light to moderate ridgeline winds.
Monday Unseasonably cool with light rain and snow showers that may be locally intense in the mid-day or afternoon hours with a chance of a thunderstorm. Also a chance of convergence at times.
Sunday Night Unseasonably cool with light rain and snow showers (moderate at Paradise). Light to moderate ridgeline winds.
Monday Light rain and snow showers (moderate at times at Paradise). A chance of a thunderstorm in the afternoon. Light to moderate ridgeline winds.
Sunday Night Unseasonably cool with decreasing light to moderate rain and snow showers. Light to moderate ridgeline and light W wind at the Pass.
Monday Unseasonably cool with light rain and snow showers that may be locally intense in the mid-day or afternoon hours with a chance of a thunderstorm. Also a chance of convergence at times. Light ridgeline and W wind at the Pass.
Sunday Night Unseasonably cool with decreasing light to moderate rain and snow showers. Light to moderate ridgeline and light W wind at the Pass.
Monday Unseasonably cool with light rain and snow showers that may be locally intense in the mid-day or afternoon hours with a chance of a thunderstorm. Light to moderate ridgeline and light W wind at the Pass becoming moderate at times in the afternoon.
Sunday Night Unseasonably cool with decreasing light rain and snow showers. Moderate ridgeline winds become light overnight.
Monday Unseasonably cool with a few light rain and snow showers. A chance of an afternoon thunderstorm along with increasing sun breaks.
Sunday Night Unseasonably cool with decreasing light rain and snow showers. Moderate ridgeline winds.
Monday Unseasonably cool with a few light rain and snow showers. A chance of an afternoon thunderstorm along with increasing sun breaks. Moderate ridgeline winds.
Sunday Night Unseasonably cool with decreasing light rain and snow showers. Light to moderate ridgeline winds.
Monday Unseasonably cool with a few light rain and snow showers and a chance of an afternoon thunderstorm along with increasing sun breaks. Light to occasionally moderate ridgeline winds.
Sunday Night Unseasonably cool with increasing light rain and snow showers become moderate in the early morning hours. Moderate to strong ridgeline winds.
Monday Unseasonably cool with moderate rain and snow showers, heavy at times in the morning hours. Moderate ridgeline winds with strong gusts.

Precipitation (in)

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

Snow Level (ft)

Sunday Evening Sunday Night Monday Morning Monday Afternoon Monday Evening Monday Night Tuesday Morning Tuesday Afternoon
Olympics 3000' 2000' 2000' 2500' 2500' 2500' 2500' 3500'
West North 3500' 2500' 2000' 2500' 2500' 2000' 2500' 3500'
West Central 3500' 2500' 2000' 3000' 3000' 2500' 2500' 3500'
West South 4000' 3000' 2500' 3000' 3000' 2500' 2500' 3500'
Stevens Pass 3500' 3000' 2500' 3000' 3000' 2500' 2500' 3500'
Snoqualmie Pass 3500' 3000' 2500' 3000' 3000' 2500' 2500' 3500'
East North 4000' 3000' 2000' 3000' 2500' 2000' 2000' 3500'
East Central 4000' 3000' 2500' 3000' 3000' 2500' 2500' 3500'
East South 4000' 3000' 2500' 3000' 3000' 2500' 2500' 3500'
Mt. Hood 4000' 3500' 3000' 3500' 3500' 2500' 3000' 3500'
Olympics Elevation
Sunday Evening 3000'
Sunday Night 2000'
Monday Morning 2000'
Monday Afternoon 2500'
Monday Evening 2500'
Monday Night 2500'
Tuesday Morning 2500'
Tuesday Afternoon 3500'
West North Elevation
Sunday Evening 3500'
Sunday Night 2500'
Monday Morning 2000'
Monday Afternoon 2500'
Monday Evening 2500'
Monday Night 2000'
Tuesday Morning 2500'
Tuesday Afternoon 3500'
West Central Elevation
Sunday Evening 3500'
Sunday Night 2500'
Monday Morning 2000'
Monday Afternoon 3000'
Monday Evening 3000'
Monday Night 2500'
Tuesday Morning 2500'
Tuesday Afternoon 3500'
West South Elevation
Sunday Evening 4000'
Sunday Night 3000'
Monday Morning 2500'
Monday Afternoon 3000'
Monday Evening 3000'
Monday Night 2500'
Tuesday Morning 2500'
Tuesday Afternoon 3500'
Stevens Pass Elevation
Sunday Evening 3500'
Sunday Night 3000'
Monday Morning 2500'
Monday Afternoon 3000'
Monday Evening 3000'
Monday Night 2500'
Tuesday Morning 2500'
Tuesday Afternoon 3500'
Snoqualmie Pass Elevation
Sunday Evening 3500'
Sunday Night 3000'
Monday Morning 2500'
Monday Afternoon 3000'
Monday Evening 3000'
Monday Night 2500'
Tuesday Morning 2500'
Tuesday Afternoon 3500'
East North Elevation
Sunday Evening 4000'
Sunday Night 3000'
Monday Morning 2000'
Monday Afternoon 3000'
Monday Evening 2500'
Monday Night 2000'
Tuesday Morning 2000'
Tuesday Afternoon 3500'
East Central Elevation
Sunday Evening 4000'
Sunday Night 3000'
Monday Morning 2500'
Monday Afternoon 3000'
Monday Evening 3000'
Monday Night 2500'
Tuesday Morning 2500'
Tuesday Afternoon 3500'
East South Elevation
Sunday Evening 4000'
Sunday Night 3000'
Monday Morning 2500'
Monday Afternoon 3000'
Monday Evening 3000'
Monday Night 2500'
Tuesday Morning 2500'
Tuesday Afternoon 3500'
Mt. Hood Elevation
Sunday Evening 4000'
Sunday Night 3500'
Monday Morning 3000'
Monday Afternoon 3500'
Monday Evening 3500'
Monday Night 2500'
Tuesday Morning 3000'
Tuesday Afternoon 3500'

5000' Temperatures (°F)

Sunday Night Monday
Max / Min Max / Min
Olympics 29 / 20 31 / 20
West North 30 / 19 30 / 20
West Central 31 / 24 30 / 22
West South 33 / 24 33 / 23
Stevens Pass 31 / 24 32 / 24
Snoqualmie Pass 31 / 23 31 / 24
East North 33 / 20 32 / 19
East Central 34 / 22 33 / 22
East South 35 / 25 34 / 23
Mt. Hood 35 / 27 33 / 26
Olympics 5000' Temperature Forecast
(Max / Min)
Sunday Night 29 / 20
Monday 31 / 20
West North 5000' Temperature Forecast
(Max / Min)
Sunday Night 30 / 19
Monday 30 / 20
West Central 5000' Temperature Forecast
(Max / Min)
Sunday Night 31 / 24
Monday 30 / 22
West South 5000' Temperature Forecast
(Max / Min)
Sunday Night 33 / 24
Monday 33 / 23
Stevens Pass 5000' Temperature Forecast
(Max / Min)
Sunday Night 31 / 24
Monday 32 / 24
Snoqualmie Pass 5000' Temperature Forecast
(Max / Min)
Sunday Night 31 / 23
Monday 31 / 24
East North 5000' Temperature Forecast
(Max / Min)
Sunday Night 33 / 20
Monday 32 / 19
East Central 5000' Temperature Forecast
(Max / Min)
Sunday Night 34 / 22
Monday 33 / 22
East South 5000' Temperature Forecast
(Max / Min)
Sunday Night 35 / 25
Monday 34 / 23
Mt. Hood 5000' Temperature Forecast
(Max / Min)
Sunday Night 35 / 27
Monday 33 / 26

Ridgeline Winds (mph)

Sunday Evening Sunday Night Monday Morning Monday Afternoon
Olympics WSW 5-15 WSW 5-15 W 0-10 WSW 5-15
West North WSW 5-15 W 0-10 W 0-10 W 5-15
West Central WSW 10-20 WSW 10-20 WNW 5-15 W 5-15
West South WSW 15-25 W 10-20 W 10-20 W 10-20
Stevens Pass W 10-20 W 10-20 W 5-15 WNW 10-20
Snoqualmie Pass W 15-25 W 15-25 W 10-20 WNW 10-20
East North WSW 10-20 WSW 5-15 WNW 5-15 W 10-20
East Central W 20-30 W 10-20 W 10-20 WNW 15-25
East South WSW 10-20 W 10-20 WNW 5-15 W 10-20
Mt. Hood W 20-30 WSW 25-35 W 15-25 W 20-30
Olympics Ridgeline Winds (mph)
Sunday Evening WSW 5-15
Sunday Night WSW 5-15
Monday Morning W 0-10
Monday Afternoon WSW 5-15
West North Ridgeline Winds (mph)
Sunday Evening WSW 5-15
Sunday Night W 0-10
Monday Morning W 0-10
Monday Afternoon W 5-15
West Central Ridgeline Winds (mph)
Sunday Evening WSW 10-20
Sunday Night WSW 10-20
Monday Morning WNW 5-15
Monday Afternoon W 5-15
West South Ridgeline Winds (mph)
Sunday Evening WSW 15-25
Sunday Night W 10-20
Monday Morning W 10-20
Monday Afternoon W 10-20
Stevens Pass Ridgeline Winds (mph)
Sunday Evening W 10-20
Sunday Night W 10-20
Monday Morning W 5-15
Monday Afternoon WNW 10-20
Snoqualmie Pass Ridgeline Winds (mph)
Sunday Evening W 15-25
Sunday Night W 15-25
Monday Morning W 10-20
Monday Afternoon WNW 10-20
East North Ridgeline Winds (mph)
Sunday Evening WSW 10-20
Sunday Night WSW 5-15
Monday Morning WNW 5-15
Monday Afternoon W 10-20
East Central Ridgeline Winds (mph)
Sunday Evening W 20-30
Sunday Night W 10-20
Monday Morning W 10-20
Monday Afternoon WNW 15-25
East South Ridgeline Winds (mph)
Sunday Evening WSW 10-20
Sunday Night W 10-20
Monday Morning WNW 5-15
Monday Afternoon W 10-20
Mt. Hood Ridgeline Winds (mph)
Sunday Evening W 20-30
Sunday Night WSW 25-35
Monday Morning W 15-25
Monday Afternoon W 20-30

Extended Weather Synopsis

The cold trough begins to fill, moderate, and slide eastward Tuesday night and Wednesday. This leads to a gradual warming trend with isolated light rain and snow showers for the west slopes of the Cascades. A weaker shortwave trough brings some light rain and snow showers to the region as it passes through on Thursday. Temperatures remain below normal throughout the period.

Extended Snow Level (ft)

Tuesday Night Wednesday Wednesday Night Thursday
West North 3000' 4000' 4500' 4500'
Snoqualmie Pass 3500' 4000' 4500' 4500'
Mt. Hood 4000' 4000' 5000' 5000'
West North Elevation
Tuesday Night 3000'
Wednesday 4000'
Wednesday Night 4500'
Thursday 4500'
Snoqualmie Pass Elevation
Tuesday Night 3500'
Wednesday 4000'
Wednesday Night 4500'
Thursday 4500'
Mt. Hood Elevation
Tuesday Night 4000'
Wednesday 4000'
Wednesday Night 5000'
Thursday 5000'

Jump to: Weather Forecast I Precipitation I Snow Level I 5000' Temps I Ridgeline Winds I Extended Weather

Previous forecast from Apr 28, 2024

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’.