Issued: 2:46 PM PDT Monday, March 11, 2024
by Robert Hahn

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

Weather Synopsis

NWAC will be closed Tuesday, March 12th as we gather and grieve following the death of one our forecasters, Matt Primomo. We will not issue regular avalanche or mountain weather forecasts on Tuesday. We will return to normal operations on Wednesday, March 13th. We appreciate the community's understanding and support during this time.

The third and strongest in a series of progressive frontal systems arrives Monday night. Light to moderate snowfall spread into the the Cascades by the end of the day on Monday. As a well-developed cold front moves through the region during the evening hours, expect moderate to heavy rain and snow, moderate to occasionally strong SSW ridgeline winds, and a brief period of warming. Snow levels peak around 3000-3500 ft in the early evening hours before cooling begins overnight. E flow could keep Snoqualmie Pass proper as wet snow with temperatures hovering around or slightly above freezing. Moderate snow showers continue as winds shift towards the SW or WSW overnight, gradually decreasing in most areas.

Moderate snow showers continue on Tuesday as the deep upper trough brings cooling aloft, creating increased convection by the afternoon, but snow levels lower from 3000 to 2500 ft. A significant convergence band likely forms around Mt Baker early Tuesday and drop southward as the day progresses. It should reach Stevens Pass by the end of the day and likely reaches Snoqualmie Pass during the evening hours.

Snow showers taper Tuesday night as the trough exits to the east and flow aloft shifts to the NNW. Expect minor amounts of trapped low-level moisture to bring a few flurries to parts of the west slopes of the Cascades very early in the day. Skies transition to partly to mostly sunny on Wednesday as a ridge builds and expands offshore.

 

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 Moderate rain and snow (heavy southern and eastern Olympics) transitioning to decreasing showers. Decreasing moderate ridgeline winds.
Tuesday Decreasing generally light snow showers. Decreasing light to moderate ridgeline winds.
Monday Night Heavy rain and snow. Moderate ridgeline winds gradually decreasing overnight.
Tuesday Decreasing moderate snow showers, locally heavy in convergence during the morning hours. Moderate ridgeline winds.
Monday Night Decreasing moderate to heavy rain and snow. Moderate ridgeline winds.
Tuesday Decreasing moderate snow showers, locally heavy in convergence, which shifts from north to south across the zone during the day.
Monday Night For the volcanoes: Heavy rain and snow transitions to moderate showers overnight. For Crystal and White Pass: Moderate rain and snow transitions to showers overnight. Moderate ridgeline winds.
Tuesday Decreasing light to moderate snow showers. Light to moderate ridgeline winds.
Monday Night Light to moderate rain and snow. Light to moderate ridgeline and light E wind switching W at the Pass in the early morning hours.
Tuesday Moderate snow showers, locally heavy in convergence. Light to moderate ridgeline and light W wind at the Pass.
Monday Night Moderate rain and snow. Light to moderate ridgeline and light E wind switching W at the Pass in the early morning hours.
Tuesday Moderate snow showers, locally heavy in convergence. Moderate ridgeline and light W wind at the Pass.
Monday Night Light to moderate rain and snow. Light to moderate ridgeline winds.
Tuesday Decreasing light snow showers. Moderate ridgeline winds.
Monday Night Moderate rain and snow transitioning to light showers. Moderate ridgeline winds.
Tuesday Mostly light snow showers. Moderate ridgeline winds.
Monday Night Moderate rain and snow transitioning to light showers. Moderate ridgeline winds.
Tuesday Mostly light snow showers. Moderate ridgeline winds.
Monday Night Moderate rain and snow. Moderate to strong ridgeline winds.
Tuesday Moderate snow showers. Moderate to strong ridgeline winds.

Issued: 2:46 PM PDT Monday, March 11, 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 0.50 - 0.75 0.25 LT 0.10 0
Mt Baker Ski Area 1.00 - 1.50 0.50 - 0.75 LT 0.25 LT 0.10
Mt. Loop - Barlow Pass 0.75 0.50 - 0.75 0.25 LT 0.10
Stevens Pass 0.25 - 0.50 0.25 - 0.50 0.25 LT 0.10
Snoqualmie Pass 0.75 -1.00 0.50 0.25 - 0.50 LT 0.10
Crystal Mt 0.50 - 0.75 0.25 LT 0.10 0
Paradise 0.75 -1.00 0.75 0.25 0
White Pass 0.25 - 0.50 0.50 LT 0.25 0
Washington Pass 0.25 - 0.50 0.25 LT 0.10 0
Mission Ridge 0.25 - 0.50 LT 0.10 0 0
Salmon la Sac - Gallagher Head 0.75 0.25 - 0.50 0.25 0
Tieton River - Darland Mt. 0.25 - 0.50 0.25 LT 0.10 0
Mt Hood Meadows 0.50 0.50 LT 0.25 0
Timberline 0.50 - 0.75 0.50 LT 0.25 0
Hurricane Ridge Precipitation (in)
Monday Night 0.50 - 0.75
Tuesday 0.25
Tuesday Night LT 0.10
Wednesday 0
Mt Baker Ski Area Precipitation (in)
Monday Night 1.00 - 1.50
Tuesday 0.50 - 0.75
Tuesday Night LT 0.25
Wednesday LT 0.10
Mt. Loop - Barlow Pass Precipitation (in)
Monday Night 0.75
Tuesday 0.50 - 0.75
Tuesday Night 0.25
Wednesday LT 0.10
Stevens Pass Precipitation (in)
Monday Night 0.25 - 0.50
Tuesday 0.25 - 0.50
Tuesday Night 0.25
Wednesday LT 0.10
Snoqualmie Pass Precipitation (in)
Monday Night 0.75 -1.00
Tuesday 0.50
Tuesday Night 0.25 - 0.50
Wednesday LT 0.10
Crystal Mt Precipitation (in)
Monday Night 0.50 - 0.75
Tuesday 0.25
Tuesday Night LT 0.10
Wednesday 0
Paradise Precipitation (in)
Monday Night 0.75 -1.00
Tuesday 0.75
Tuesday Night 0.25
Wednesday 0
White Pass Precipitation (in)
Monday Night 0.25 - 0.50
Tuesday 0.50
Tuesday Night LT 0.25
Wednesday 0
Washington Pass Precipitation (in)
Monday Night 0.25 - 0.50
Tuesday 0.25
Tuesday Night LT 0.10
Wednesday 0
Mission Ridge Precipitation (in)
Monday Night 0.25 - 0.50
Tuesday LT 0.10
Tuesday Night 0
Wednesday 0
Salmon la Sac - Gallagher Head Precipitation (in)
Monday Night 0.75
Tuesday 0.25 - 0.50
Tuesday Night 0.25
Wednesday 0
Tieton River - Darland Mt. Precipitation (in)
Monday Night 0.25 - 0.50
Tuesday 0.25
Tuesday Night LT 0.10
Wednesday 0
Mt Hood Meadows Precipitation (in)
Monday Night 0.50
Tuesday 0.50
Tuesday Night LT 0.25
Wednesday 0
Timberline Precipitation (in)
Monday Night 0.50 - 0.75
Tuesday 0.50
Tuesday Night LT 0.25
Wednesday 0

Issued: 2:46 PM PDT Monday, March 11, 2024

Snow Level (ft)

Monday Evening* Monday Night Tuesday Morning Tuesday Afternoon Tuesday Evening Tuesday Night Wednesday Morning Wednesday Afternoon
Olympics 3000' 3000' 2500' 2500' 2000' 1500' 1500' 3000'
West North 3000' 3000' 2500' 2500' 2000' 1500' 1000' 3000'
West Central 3000' 3000' 2500' 2500' 2000' 1500' 1500' 3000'
West South 3500' 3000' 3000' 2500' 2000' 1500' 1500' 3500'
Stevens Pass 3000' 3000' 3000' 3000' 2000' 1500' 1500' 3000'
Snoqualmie Pass 3000' 3000' 3000' 2500' 2000' 1500' 1500' 3000'
East North 3000' 3000' 3000' 3000' 2000' 500' 500' 3500'
East Central 3000' 3000' 3000' 3000' 2000' 1500' 1500' 3500'
East South 3500' 3000' 3000' 3000' 2000' 1500' 1500' 4000'
Mt. Hood 3500' 3500' 3000' 2500' 2500' 2000' 2000' 3500'
Olympics Elevation
Monday Evening* 3000'
Monday Night 3000'
Tuesday Morning 2500'
Tuesday Afternoon 2500'
Tuesday Evening 2000'
Tuesday Night 1500'
Wednesday Morning 1500'
Wednesday Afternoon 3000'
West North Elevation
Monday Evening* 3000'
Monday Night 3000'
Tuesday Morning 2500'
Tuesday Afternoon 2500'
Tuesday Evening 2000'
Tuesday Night 1500'
Wednesday Morning 1000'
Wednesday Afternoon 3000'
West Central Elevation
Monday Evening* 3000'
Monday Night 3000'
Tuesday Morning 2500'
Tuesday Afternoon 2500'
Tuesday Evening 2000'
Tuesday Night 1500'
Wednesday Morning 1500'
Wednesday Afternoon 3000'
West South Elevation
Monday Evening* 3500'
Monday Night 3000'
Tuesday Morning 3000'
Tuesday Afternoon 2500'
Tuesday Evening 2000'
Tuesday Night 1500'
Wednesday Morning 1500'
Wednesday Afternoon 3500'
Stevens Pass Elevation
Monday Evening* 3000'
Monday Night 3000'
Tuesday Morning 3000'
Tuesday Afternoon 3000'
Tuesday Evening 2000'
Tuesday Night 1500'
Wednesday Morning 1500'
Wednesday Afternoon 3000'
Snoqualmie Pass Elevation
Monday Evening* 3000'
Monday Night 3000'
Tuesday Morning 3000'
Tuesday Afternoon 2500'
Tuesday Evening 2000'
Tuesday Night 1500'
Wednesday Morning 1500'
Wednesday Afternoon 3000'
East North Elevation
Monday Evening* 3000'
Monday Night 3000'
Tuesday Morning 3000'
Tuesday Afternoon 3000'
Tuesday Evening 2000'
Tuesday Night 500'
Wednesday Morning 500'
Wednesday Afternoon 3500'
East Central Elevation
Monday Evening* 3000'
Monday Night 3000'
Tuesday Morning 3000'
Tuesday Afternoon 3000'
Tuesday Evening 2000'
Tuesday Night 1500'
Wednesday Morning 1500'
Wednesday Afternoon 3500'
East South Elevation
Monday Evening* 3500'
Monday Night 3000'
Tuesday Morning 3000'
Tuesday Afternoon 3000'
Tuesday Evening 2000'
Tuesday Night 1500'
Wednesday Morning 1500'
Wednesday Afternoon 4000'
Mt. Hood Elevation
Monday Evening* 3500'
Monday Night 3500'
Tuesday Morning 3000'
Tuesday Afternoon 2500'
Tuesday Evening 2500'
Tuesday Night 2000'
Wednesday Morning 2000'
Wednesday Afternoon 3500'

Issued: 2:46 PM PDT Monday, March 11, 2024

5000' Temperatures (°F)

Monday Night Tuesday
Max / Min Max / Min
Olympics 27 / 24 28 / 23
West North 27 / 26 28 / 25
West Central 28 / 26 28 / 25
West South 29 / 27 28 / 26
Stevens Pass 29 / 26 28 / 26
Snoqualmie Pass 29 / 27 28 / 25
East North 27 / 24 29 / 24
East Central 29 / 26 29 / 26
East South 29 / 26 29 / 26
Mt. Hood 31 / 27 29 / 26
Olympics 5000' Temperature Forecast
(Max / Min)
Monday Night 27 / 24
Tuesday 28 / 23
West North 5000' Temperature Forecast
(Max / Min)
Monday Night 27 / 26
Tuesday 28 / 25
West Central 5000' Temperature Forecast
(Max / Min)
Monday Night 28 / 26
Tuesday 28 / 25
West South 5000' Temperature Forecast
(Max / Min)
Monday Night 29 / 27
Tuesday 28 / 26
Stevens Pass 5000' Temperature Forecast
(Max / Min)
Monday Night 29 / 26
Tuesday 28 / 26
Snoqualmie Pass 5000' Temperature Forecast
(Max / Min)
Monday Night 29 / 27
Tuesday 28 / 25
East North 5000' Temperature Forecast
(Max / Min)
Monday Night 27 / 24
Tuesday 29 / 24
East Central 5000' Temperature Forecast
(Max / Min)
Monday Night 29 / 26
Tuesday 29 / 26
East South 5000' Temperature Forecast
(Max / Min)
Monday Night 29 / 26
Tuesday 29 / 26
Mt. Hood 5000' Temperature Forecast
(Max / Min)
Monday Night 31 / 27
Tuesday 29 / 26

Issued: 2:46 PM PDT Monday, March 11, 2024

Ridgeline Winds (mph)

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

Issued: 2:46 PM PDT Monday, March 11, 2024

Extended Weather Synopsis

The ridge of high pressure amplifies and brings warming temperatures aloft. Expect inversions during the morning hours and significantly milder temperatures late Thursday. Expect much more significant warming on Friday as freezing levels rise up to 10000 ft in the afternoon once the low-level inversions mix out.

Extended Snow Level (ft)

Wednesday Night Thursday Thursday Night* Friday *
West North 2000' 5000' 7000' 8000'
Snoqualmie Pass 2000' 5500' 7000' 8500'
Mt. Hood 2500' 5500' 7000' 8500'
West North Elevation
Wednesday Night 2000'
Thursday 5000'
Thursday Night* 7000'
Friday * 8000'
Snoqualmie Pass Elevation
Wednesday Night 2000'
Thursday 5500'
Thursday Night* 7000'
Friday * 8500'
Mt. Hood Elevation
Wednesday Night 2500'
Thursday 5500'
Thursday Night* 7000'
Friday * 8500'

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

Previous forecast from Mar 11, 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’.