The cooldown associated with a broad upper trough dropping southward has been dramatic. Freezing levels at Quilliyute dropped from 9,300 to 3,300 from Sunday to Monday morning. Cooling continues as the trough settles into the region. The upper-level flow features WNW winds as the trough slides just to our north over central and southern British Columbia. As of Monday afternoon, these winds are enhanced by a 10 mb temperature gradient across the Cascades. These gradients and associated low-level winds likely peak Monday night, before gradually starting to subside on Tuesday. Expect moderate ridgeline winds for areas near and east of the Cascade Crest, including the mountain gaps. This flow pattern has produced several weak convergence bands in the central and northern Puget Sound regions but most precipitation has been light. Rain/snow shower activity peaks Monday night for the central and northern Cascades. With continued cooling and snow levels dropping down to 2500 ft or lower, expect several inches of snow from Snoqualmie Pass to Mt Baker, with perhaps a few areas slightly west of the Cascade Crest getting a bit more.
Snow showers become more isolated on Tuesday as the upper trough shifts toward northern Idaho. Cold temperatures aloft could drive an isolated convective shower or two with a slight uptick in light to moderate ridgeline winds, clouds, and shower activity in the afternoon.
The Pacific Northwest lingers near the western edge of the exiting trough Tuesday night and Wednesday. Expect a cool start to Wednesday with freezing levels rebounding to around 5000 ft or slightly higher. More sunshine is in store with lighter winds shifting NWerly.
NWAC will issue daily Mountain Weather Forecasts through April 28th, with the exception of April 18th, when we will be closed for an end-of-season forecaster meeting.
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
Night
A few snow showers, mainly in the western part. Mostly cloudy, then becoming partly cloudy in the early morning hours.
Tuesday
More sun than clouds in the morning, then more clouds than sun in the afternoon.
Monday
Night
Mostly cloudy with scattered snow showers.
Tuesday
Partly cloudy with a few snow showers.
Monday
Night
Mostly cloudy with scattered light snow showers and weak convergence at times. Moderate ridgeline winds near the Cascade Crest.
Tuesday
Partly to mostly cloudy with scattered light snow showers. Moderate ridgeline winds near the Cascade Crest.
Monday
Night
Mostly cloudy with a few light rain/snow showers. Moderate ridgeline winds near the Cascade Crest.
Tuesday
Partly to mostly cloudy with isolated light snow showers. Moderate ridgeline winds near the Cascade Crest.
Monday
Night
Mostly cloudy with a few light rain/snow showers. Light to moderate ridgeline and light W wind at the Pass.
Tuesday
Partly cloudy with a few light rain/snow showers, primarily in the afternoon. Light to moderate ridgeline and light W wind at the Pass.
Monday
Night
Mostly cloudy with a few light rain/snow showers. Moderate ridgeline and light to moderate W wind at the Pass.
Tuesday
Partly to mostly cloudy with a few light rain/snow showers, primarily in the afternoon. Light to moderate ridgeline and light W wind at the Pass.
Monday
Night
A few light snow showers near the Cascade Crest, otherwise partly cloudy. Moderate ridgeline winds.
Tuesday
Isolated light rain/snow showers mainly in the afternoon. Decreasing light to moderate ridgeline winds.
Monday
Night
A few light rain/snow showers and weak convergence spillover, decreasing overnight. Moderate ridgeline winds.
Tuesday
Isolated light rain/snow showers mainly in the afternoon and near the Cascade Crest. Otherwise, partly to mostly sunny skies. Decreasing light to moderate ridgeline winds.
Monday
Night
Partly cloudy with a few sprinkles/flurries near the Cascade Crest/
Tuesday
Partly to mostly sunny.
Monday
Night
Mostly cloudy with a few light rain/snow showers on the west slopes of Mt Hood. Moderate ridgeline winds.
Tuesday
Partly to mostly cloudy. Light to moderate ridgeline winds.
Issued: 2:40 PM PDT Monday, April 15, 2024
Precipitation (in)
Monday Night
Tuesday
Tuesday Night
Wednesday
5 pm - 5 am
5 am - 5 pm
5 pm - 5 am
5 am - 5 pm
Hurricane Ridge
LT 0.10
LT 0.10
0
0
Mt Baker Ski Area
LT 0.25
LT 0.10
LT 0.10
0
Mt. Loop - Barlow Pass
LT 0.25
LT 0.10
0
0
Stevens Pass
LT 0.10
LT 0.10
0
LT 0.10
Snoqualmie Pass
LT 0.25
LT 0.10
0
0
Crystal Mt
LT 0.10
LT 0.10
0
0
Paradise
LT 0.10
LT 0.10
LT 0.10
0
White Pass
LT 0.10
0
0
0
Washington Pass
0
LT 0.10
LT 0.10
0
Mission Ridge
0
0
0
0
Salmon la Sac - Gallagher Head
LT 0.10
LT 0.10
0
0
Tieton River - Darland Mt.
0
0
0
0
Mt Hood Meadows
0
0
0
0
Timberline
LT 0.10
0
0
0
Hurricane Ridge
Precipitation (in)
Monday Night
LT 0.10
Tuesday
LT 0.10
Tuesday Night
0
Wednesday
0
Mt Baker Ski Area
Precipitation (in)
Monday Night
LT 0.25
Tuesday
LT 0.10
Tuesday Night
LT 0.10
Wednesday
0
Mt. Loop - Barlow Pass
Precipitation (in)
Monday Night
LT 0.25
Tuesday
LT 0.10
Tuesday Night
0
Wednesday
0
Stevens Pass
Precipitation (in)
Monday Night
LT 0.10
Tuesday
LT 0.10
Tuesday Night
0
Wednesday
LT 0.10
Snoqualmie Pass
Precipitation (in)
Monday Night
LT 0.25
Tuesday
LT 0.10
Tuesday Night
0
Wednesday
0
Crystal Mt
Precipitation (in)
Monday Night
LT 0.10
Tuesday
LT 0.10
Tuesday Night
0
Wednesday
0
Paradise
Precipitation (in)
Monday Night
LT 0.10
Tuesday
LT 0.10
Tuesday Night
LT 0.10
Wednesday
0
White Pass
Precipitation (in)
Monday Night
LT 0.10
Tuesday
0
Tuesday Night
0
Wednesday
0
Washington Pass
Precipitation (in)
Monday Night
0
Tuesday
LT 0.10
Tuesday Night
LT 0.10
Wednesday
0
Mission Ridge
Precipitation (in)
Monday Night
0
Tuesday
0
Tuesday Night
0
Wednesday
0
Salmon la Sac - Gallagher Head
Precipitation (in)
Monday Night
LT 0.10
Tuesday
LT 0.10
Tuesday Night
0
Wednesday
0
Tieton River - Darland Mt.
Precipitation (in)
Monday Night
0
Tuesday
0
Tuesday Night
0
Wednesday
0
Mt Hood Meadows
Precipitation (in)
Monday Night
0
Tuesday
0
Tuesday Night
0
Wednesday
0
Timberline
Precipitation (in)
Monday Night
LT 0.10
Tuesday
0
Tuesday Night
0
Wednesday
0
Issued: 2:40 PM PDT Monday, April 15, 2024
Snow Level (ft)
Monday
Evening
Monday
Night
Tuesday
Morning
Tuesday
Afternoon
Tuesday
Evening
Tuesday
Night
Wednesday
Morning
Wednesday
Afternoon
Olympics
3000'
2500'
2500'
3000'
3500'
3500'
4000'
5000'
West North
3000'
1500'
1500'
2500'
3000'
2500'
3000'
5000'
West Central
3000'
2000'
1500'
2500'
3000'
2500'
3000'
5000'
West South
3500'
2500'
2500'
3500'
4000'
2500'
3000'
5000'
Stevens Pass
3500'
2500'
2000'
3500'
3500'
2500'
3000'
5000'
Snoqualmie Pass
3500'
2500'
2000'
3500'
3500'
2500'
3000'
5000'
East North
4500'
2500'
2000'
3500'
3500'
2000'
2500'
5000'
East Central
4500'
3000'
2500'
4000'
4000'
2500'
3000'
5000'
East South
4500'
3000'
2500'
4500'
4000'
2500'
3000'
5000'
Mt. Hood
4000'
2500'
3000'
5000'
4000'
2500'
3000'
5000'
Olympics
Elevation
Monday
Evening
3000'
Monday
Night
2500'
Tuesday
Morning
2500'
Tuesday
Afternoon
3000'
Tuesday
Evening
3500'
Tuesday
Night
3500'
Wednesday
Morning
4000'
Wednesday
Afternoon
5000'
West North
Elevation
Monday
Evening
3000'
Monday
Night
1500'
Tuesday
Morning
1500'
Tuesday
Afternoon
2500'
Tuesday
Evening
3000'
Tuesday
Night
2500'
Wednesday
Morning
3000'
Wednesday
Afternoon
5000'
West Central
Elevation
Monday
Evening
3000'
Monday
Night
2000'
Tuesday
Morning
1500'
Tuesday
Afternoon
2500'
Tuesday
Evening
3000'
Tuesday
Night
2500'
Wednesday
Morning
3000'
Wednesday
Afternoon
5000'
West South
Elevation
Monday
Evening
3500'
Monday
Night
2500'
Tuesday
Morning
2500'
Tuesday
Afternoon
3500'
Tuesday
Evening
4000'
Tuesday
Night
2500'
Wednesday
Morning
3000'
Wednesday
Afternoon
5000'
Stevens Pass
Elevation
Monday
Evening
3500'
Monday
Night
2500'
Tuesday
Morning
2000'
Tuesday
Afternoon
3500'
Tuesday
Evening
3500'
Tuesday
Night
2500'
Wednesday
Morning
3000'
Wednesday
Afternoon
5000'
Snoqualmie Pass
Elevation
Monday
Evening
3500'
Monday
Night
2500'
Tuesday
Morning
2000'
Tuesday
Afternoon
3500'
Tuesday
Evening
3500'
Tuesday
Night
2500'
Wednesday
Morning
3000'
Wednesday
Afternoon
5000'
East North
Elevation
Monday
Evening
4500'
Monday
Night
2500'
Tuesday
Morning
2000'
Tuesday
Afternoon
3500'
Tuesday
Evening
3500'
Tuesday
Night
2000'
Wednesday
Morning
2500'
Wednesday
Afternoon
5000'
East Central
Elevation
Monday
Evening
4500'
Monday
Night
3000'
Tuesday
Morning
2500'
Tuesday
Afternoon
4000'
Tuesday
Evening
4000'
Tuesday
Night
2500'
Wednesday
Morning
3000'
Wednesday
Afternoon
5000'
East South
Elevation
Monday
Evening
4500'
Monday
Night
3000'
Tuesday
Morning
2500'
Tuesday
Afternoon
4500'
Tuesday
Evening
4000'
Tuesday
Night
2500'
Wednesday
Morning
3000'
Wednesday
Afternoon
5000'
Mt. Hood
Elevation
Monday
Evening
4000'
Monday
Night
2500'
Tuesday
Morning
3000'
Tuesday
Afternoon
5000'
Tuesday
Evening
4000'
Tuesday
Night
2500'
Wednesday
Morning
3000'
Wednesday
Afternoon
5000'
Issued: 2:40 PM PDT Monday, April 15, 2024
5000' Temperatures (°F)
Monday
Night
Tuesday
Max / Min
Max / Min
Olympics
30 / 22
33 / 21
West North
30 / 22
31 / 22
West Central
29 / 23
31 / 23
West South
34 / 23
34 / 23
Stevens Pass
32 / 23
32 / 23
Snoqualmie Pass
32 / 23
31 / 23
East North
32 / 19
31 / 18
East Central
33 / 23
32 / 23
East South
35 / 23
35 / 21
Mt. Hood
36 / 25
37 / 25
Olympics
5000' Temperature Forecast (Max / Min)
Monday
Night
30 / 22
Tuesday
33 / 21
West North
5000' Temperature Forecast (Max / Min)
Monday
Night
30 / 22
Tuesday
31 / 22
West Central
5000' Temperature Forecast (Max / Min)
Monday
Night
29 / 23
Tuesday
31 / 23
West South
5000' Temperature Forecast (Max / Min)
Monday
Night
34 / 23
Tuesday
34 / 23
Stevens Pass
5000' Temperature Forecast (Max / Min)
Monday
Night
32 / 23
Tuesday
32 / 23
Snoqualmie Pass
5000' Temperature Forecast (Max / Min)
Monday
Night
32 / 23
Tuesday
31 / 23
East North
5000' Temperature Forecast (Max / Min)
Monday
Night
32 / 19
Tuesday
31 / 18
East Central
5000' Temperature Forecast (Max / Min)
Monday
Night
33 / 23
Tuesday
32 / 23
East South
5000' Temperature Forecast (Max / Min)
Monday
Night
35 / 23
Tuesday
35 / 21
Mt. Hood
5000' Temperature Forecast (Max / Min)
Monday
Night
36 / 25
Tuesday
37 / 25
Issued: 2:40 PM PDT Monday, April 15, 2024
Ridgeline Winds (mph)
Monday
Evening
Monday
Night
Tuesday
Morning
Tuesday
Afternoon
Olympics
WSW 10-20
WNW 5-15
WNW 0-10
WNW 5-15
West North
WSW 10-20
W 10-20
W 5-15
WNW 10-20
West Central
WNW 10-20
WNW 10-20
WNW 10-20
WNW 10-20
West South
WNW 10-20
WNW 10-20
WNW 10-20
WNW 10-20
Stevens Pass
W 10-20
WNW 15-25
WNW 10-20
WNW 10-20
Snoqualmie Pass
WNW 15-25
WNW 20-30
WNW 15-25
WNW 10-20
East North
W 20-30
W 20-30
WNW 10-20
WNW 10-20
East Central
W 20-30
WNW 20-30
NW 10-20
WNW 10-20
East South
W 15-25
WNW 10-20
WNW 10-20
WNW 10-20
Mt. Hood
W 20-30
W 20-30
W 10-20
W 10-20
Olympics
Ridgeline Winds (mph)
Monday
Evening
WSW
10-20
Monday
Night
WNW
5-15
Tuesday
Morning
WNW
0-10
Tuesday
Afternoon
WNW
5-15
West North
Ridgeline Winds (mph)
Monday
Evening
WSW
10-20
Monday
Night
W
10-20
Tuesday
Morning
W
5-15
Tuesday
Afternoon
WNW
10-20
West Central
Ridgeline Winds (mph)
Monday
Evening
WNW
10-20
Monday
Night
WNW
10-20
Tuesday
Morning
WNW
10-20
Tuesday
Afternoon
WNW
10-20
West South
Ridgeline Winds (mph)
Monday
Evening
WNW
10-20
Monday
Night
WNW
10-20
Tuesday
Morning
WNW
10-20
Tuesday
Afternoon
WNW
10-20
Stevens Pass
Ridgeline Winds (mph)
Monday
Evening
W
10-20
Monday
Night
WNW
15-25
Tuesday
Morning
WNW
10-20
Tuesday
Afternoon
WNW
10-20
Snoqualmie Pass
Ridgeline Winds (mph)
Monday
Evening
WNW
15-25
Monday
Night
WNW
20-30
Tuesday
Morning
WNW
15-25
Tuesday
Afternoon
WNW
10-20
East North
Ridgeline Winds (mph)
Monday
Evening
W
20-30
Monday
Night
W
20-30
Tuesday
Morning
WNW
10-20
Tuesday
Afternoon
WNW
10-20
East Central
Ridgeline Winds (mph)
Monday
Evening
W
20-30
Monday
Night
WNW
20-30
Tuesday
Morning
NW
10-20
Tuesday
Afternoon
WNW
10-20
East South
Ridgeline Winds (mph)
Monday
Evening
W
15-25
Monday
Night
WNW
10-20
Tuesday
Morning
WNW
10-20
Tuesday
Afternoon
WNW
10-20
Mt. Hood
Ridgeline Winds (mph)
Monday
Evening
W
20-30
Monday
Night
W
20-30
Tuesday
Morning
W
10-20
Tuesday
Afternoon
W
10-20
Issued: 2:40 PM PDT Monday, April 15, 2024
Extended Weather Synopsis
The offshore ridge continues to edge towards the coastline but doesn't fully amplify. Expect temperatures near seasonal norms with 5000-6000 ft freezing levels in the afternoons and good overnight refreezes.
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).