Issued: 2:00 PM PST Thursday, November 25, 2021
by Dallas Glass

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

Weather Synopsis

The wet and wild weather will continue as we head into the holiday weekend. The first in a series of atmospheric rivers will continue to spread rain and high elevation snow from north to south across western Washington Thanksgiving night. The heaviest precipitation is expected around the Cascade Volcanoes and in a Puget Sound Convergence Zone which should take aim at areas from the Mountain Loop Highway to Snoqualmie Pass. Snow levels with this first storm will remain well above trailhead and pass levels. The notable exception is lingering pockets of colder air holding strong near the Canadian border, particularly in the Methow region. In addition to the warm temperatures and heavy precipitation, strong westerly winds in most areas will make for very storm conditions. 

As we head into Friday, slightly cooler weather will begin to shift into the region. As it does so, most of the precipitation ends. Notable rain and snow should continue for locations near Mt Hood and where the convergence zone remains focussed. By mid-late afternoon, a brief break in the action should allow most locations to dry out as shower activity comes to an end. A few sun breaks could even be possible for areas east of the Cascade crest. 

This break appears short-lived. A second, and slightly stronger, atmospheric river will begin to approach the region Saturday morning. Weather models disagree slightly with the timing of this system but generally agree on the major impacts and pattern. Moderate to heavy precipitation and strong winds will spread from NW to SE across the area Saturday afternoon. Locations in the Olympics and N. Cascades will see the most significant accumulations during the day, but as the storm continues, precipitation will spread further south. Very warm air should arrive with the onset of precipitation and send snow levels soaring. Right now, this appears to be yet another mostly rain and very high elevation snow event for the mountains. 

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
Thursday Night Cloudy with rain becoming rain showers. Strong W winds decreasing slightly.
Friday Mostly cloudy with isolated showers mainly in the morning. Light to moderate W winds.
Thursday Night Cloudy with rain and snow, becoming showers by morning. Moderate to strong SW winds.
Friday Mostly cloudy with showers mainly in the morning. Moderate W winds decreasing.
Thursday Night Cloudy with moderate to heavy rain and high elevation snow. Puget Sound Convergence Zone bringing locally heavier precipitation. Moderate to strong SW winds.
Friday Puget Sound Convergence Zone strongest in the morning, bringing locally heavier precipitation. Showers elsewhere. Moderate W winds decreasing.
Thursday Night Moderate to heavy rain and high elevation snow. Greatest accumulations near the volcanoes. Moderate to strong W winds.
Friday Rain and high elevation snow showers, particularly in the morning. Heaviest precipitation near the volcanoes, particularly Mt St Helens and Mt Adams. Moderate W winds decreasing.
Thursday Night Cloudy with moderate to heavy rain and high elevation snow. Puget Sound Convergence Zone bringing locally heavier precipitation. Moderate W winds.
Friday Puget Sound Convergence Zone, strongest in the morning, bringing locally heavier precipitation. Moderate W winds decreasing in the afternoon.
Thursday Night Cloudy with moderate to heavy rain and high elevation snow. Puget Sound Convergence Zone bringing locally heavier precipitation. Moderate to strong W winds decreasing slightly.
Friday Puget Sound Convergence Zone, strongest in the morning, bringing locally heavier precipitation. Moderate W winds.
Thursday Night Mostly cloudy with rain and snow showers. Moderate to strong W winds.
Friday Mostly cloudy with scattered rain and snow showers mostly in the morning. Moderate to strong W winds should decrease slightly in the afternoon.
Thursday Night Cloudy to mostly cloudy. Rain and snow, heaviest near the Cascade crest. Scattered showers in the Wenatchee Mts. Strong W winds.
Friday Mostly to partly cloudy with showers lingering near the crest. Strong W winds should decrease slightly in the afternoon.
Thursday Night Cloudy with rain and high elevation snow showers, heaviest near the Cascade crest. Strong W winds.
Friday Mostly to partly cloudy with lingering showers. Strong W winds should decrease slightly in the afternoon.
Thursday Night Cloudy. Rain and high elevation snow should become heavier around midnight. Strong W winds.
Friday Rain and high elevation snow, heaviest in the morning, turning to showers in the afternoon. Strong W winds decreasing slightly.

Precipitation (in)

Thursday Night Friday Friday Night Saturday
4 pm - 4 am 4 am - 4 pm 4 pm - 4 am 4 am - 4 pm
Hurricane Ridge 0.25 - 0.50 LT 0.10 0 0.50
Mt Baker Ski Area 1.00 0.25 0 1.00
Mt. Loop - Barlow Pass 1.50 - 2.00 0.25 - 0.50 0 0.50 - 0.75
Stevens Pass 1.50 0.25 0 0.25 - 0.50
Snoqualmie Pass 1.50 - 2.00 LT 0.25 0 0.25 - 0.50
Crystal Mt 0.50 LT 0.10 0 0.25
Paradise 1.50 - 2.00 0.25 0 0.50 - 0.75
White Pass 0.75 LT 0.25 0 0.25
Washington Pass 0.75 LT 0.25 0 0.25 - 0.50
Mission Ridge 0.25 LT 0.10 0 LT 0.10
Salmon la Sac - Gallagher Head 0.75 -1.00 LT 0.25 0 0.25
Tieton River - Darland Mt. 0.25 - 0.50 0.50 0 LT 0.25
Mt Hood Meadows 0.75 0.75 LT 0.10 0.25
Timberline 0.75 -1.00 0.75 LT 0.10 0.25
Hurricane Ridge Precipitation (in)
Thursday Night 0.25 - 0.50
Friday LT 0.10
Friday Night 0
Saturday 0.50
Mt Baker Ski Area Precipitation (in)
Thursday Night 1.00
Friday 0.25
Friday Night 0
Saturday 1.00
Mt. Loop - Barlow Pass Precipitation (in)
Thursday Night 1.50 - 2.00
Friday 0.25 - 0.50
Friday Night 0
Saturday 0.50 - 0.75
Stevens Pass Precipitation (in)
Thursday Night 1.50
Friday 0.25
Friday Night 0
Saturday 0.25 - 0.50
Snoqualmie Pass Precipitation (in)
Thursday Night 1.50 - 2.00
Friday LT 0.25
Friday Night 0
Saturday 0.25 - 0.50
Crystal Mt Precipitation (in)
Thursday Night 0.50
Friday LT 0.10
Friday Night 0
Saturday 0.25
Paradise Precipitation (in)
Thursday Night 1.50 - 2.00
Friday 0.25
Friday Night 0
Saturday 0.50 - 0.75
White Pass Precipitation (in)
Thursday Night 0.75
Friday LT 0.25
Friday Night 0
Saturday 0.25
Washington Pass Precipitation (in)
Thursday Night 0.75
Friday LT 0.25
Friday Night 0
Saturday 0.25 - 0.50
Mission Ridge Precipitation (in)
Thursday Night 0.25
Friday LT 0.10
Friday Night 0
Saturday LT 0.10
Salmon la Sac - Gallagher Head Precipitation (in)
Thursday Night 0.75 -1.00
Friday LT 0.25
Friday Night 0
Saturday 0.25
Tieton River - Darland Mt. Precipitation (in)
Thursday Night 0.25 - 0.50
Friday 0.50
Friday Night 0
Saturday LT 0.25
Mt Hood Meadows Precipitation (in)
Thursday Night 0.75
Friday 0.75
Friday Night LT 0.10
Saturday 0.25
Timberline Precipitation (in)
Thursday Night 0.75 -1.00
Friday 0.75
Friday Night LT 0.10
Saturday 0.25

Snow Level (ft)

Thursday Evening Thursday Night Friday Morning Friday Afternoon Friday Evening Friday Night* Saturday Morning* Saturday Afternoon*
Olympics 7500' 6500' 5500' 4500' 4500' 4500' 6500' 9500'
West North 5000' 5000' 4500' 4000' 4000' 3500' 4000' 7000'
West Central 6500' 6000' 5500' 5000' 5000' 4500' 5500' 8000'
West South 8000' 7000' 6000' 5500' 5500' 5500' 6500' 9000'
Stevens Pass 6500' 6000' 5500' 5000' 5000' 4500' 4000' 7500'
Snoqualmie Pass 7000' 7000' 6000' 5500' 5000' 5000' 5000' 8500'
East North 5500' 5000' 5000' 4500' 4000' 3000' 3000' 5000'
East Central 7000' 6500' 5500' 5000' 4500' 4000' 3500' 7500'
East South 8000' 7500' 6500' 5500' 5000' 5000' 5500' 9000'
Mt. Hood 9000' 8500' 7000' 6500' 6500' 6500' 7500' 9500'
Olympics Elevation
Thursday Evening 7500'
Thursday Night 6500'
Friday Morning 5500'
Friday Afternoon 4500'
Friday Evening 4500'
Friday Night* 4500'
Saturday Morning* 6500'
Saturday Afternoon* 9500'
West North Elevation
Thursday Evening 5000'
Thursday Night 5000'
Friday Morning 4500'
Friday Afternoon 4000'
Friday Evening 4000'
Friday Night* 3500'
Saturday Morning* 4000'
Saturday Afternoon* 7000'
West Central Elevation
Thursday Evening 6500'
Thursday Night 6000'
Friday Morning 5500'
Friday Afternoon 5000'
Friday Evening 5000'
Friday Night* 4500'
Saturday Morning* 5500'
Saturday Afternoon* 8000'
West South Elevation
Thursday Evening 8000'
Thursday Night 7000'
Friday Morning 6000'
Friday Afternoon 5500'
Friday Evening 5500'
Friday Night* 5500'
Saturday Morning* 6500'
Saturday Afternoon* 9000'
Stevens Pass Elevation
Thursday Evening 6500'
Thursday Night 6000'
Friday Morning 5500'
Friday Afternoon 5000'
Friday Evening 5000'
Friday Night* 4500'
Saturday Morning* 4000'
Saturday Afternoon* 7500'
Snoqualmie Pass Elevation
Thursday Evening 7000'
Thursday Night 7000'
Friday Morning 6000'
Friday Afternoon 5500'
Friday Evening 5000'
Friday Night* 5000'
Saturday Morning* 5000'
Saturday Afternoon* 8500'
East North Elevation
Thursday Evening 5500'
Thursday Night 5000'
Friday Morning 5000'
Friday Afternoon 4500'
Friday Evening 4000'
Friday Night* 3000'
Saturday Morning* 3000'
Saturday Afternoon* 5000'
East Central Elevation
Thursday Evening 7000'
Thursday Night 6500'
Friday Morning 5500'
Friday Afternoon 5000'
Friday Evening 4500'
Friday Night* 4000'
Saturday Morning* 3500'
Saturday Afternoon* 7500'
East South Elevation
Thursday Evening 8000'
Thursday Night 7500'
Friday Morning 6500'
Friday Afternoon 5500'
Friday Evening 5000'
Friday Night* 5000'
Saturday Morning* 5500'
Saturday Afternoon* 9000'
Mt. Hood Elevation
Thursday Evening 9000'
Thursday Night 8500'
Friday Morning 7000'
Friday Afternoon 6500'
Friday Evening 6500'
Friday Night* 6500'
Saturday Morning* 7500'
Saturday Afternoon* 9500'

5000' Temperatures (°F)

Thursday Night Friday
Max / Min Max / Min
Olympics 38 / 35 38 / 31
West North 36 / 32 36 / 28
West Central 40 / 34 36 / 29
West South 41 / 34 39 / 33
Stevens Pass 39 / 35 36 / 31
Snoqualmie Pass 40 / 35 37 / 32
East North 35 / 33 36 / 27
East Central 39 / 35 36 / 31
East South 40 / 34 36 / 34
Mt. Hood 42 / 35 39 / 34
Olympics 5000' Temperature Forecast
(Max / Min)
Thursday Night 38 / 35
Friday 38 / 31
West North 5000' Temperature Forecast
(Max / Min)
Thursday Night 36 / 32
Friday 36 / 28
West Central 5000' Temperature Forecast
(Max / Min)
Thursday Night 40 / 34
Friday 36 / 29
West South 5000' Temperature Forecast
(Max / Min)
Thursday Night 41 / 34
Friday 39 / 33
Stevens Pass 5000' Temperature Forecast
(Max / Min)
Thursday Night 39 / 35
Friday 36 / 31
Snoqualmie Pass 5000' Temperature Forecast
(Max / Min)
Thursday Night 40 / 35
Friday 37 / 32
East North 5000' Temperature Forecast
(Max / Min)
Thursday Night 35 / 33
Friday 36 / 27
East Central 5000' Temperature Forecast
(Max / Min)
Thursday Night 39 / 35
Friday 36 / 31
East South 5000' Temperature Forecast
(Max / Min)
Thursday Night 40 / 34
Friday 36 / 34
Mt. Hood 5000' Temperature Forecast
(Max / Min)
Thursday Night 42 / 35
Friday 39 / 34

Ridgeline Winds (mph)

Thursday Evening Thursday Night Friday Morning Friday Afternoon
Olympics WSW 15-25 W 10-20 W 10-20 WSW 5-15
West North SSW 20-30 WSW 15-25 W 15-25 W 5-15
West Central SW 20-30 W 15-25 W 15-25 W 5-15
West South WSW 20-30 W 20-30 W 15-25 W 10-20
Stevens Pass WSW 10-20 W 10-20 W 10-20 W 5-15
Snoqualmie Pass WSW 20-30 W 15-25 W 15-25 W 15-25
East North WSW 20-30 W 20-30 W 20-30 W 15-25
East Central WSW 30-40 W 30-40 W 30-40 W 20-30
East South WSW 30-40 W 35-50 W 30-40 W 20-30
Mt. Hood WSW 30-40 W 40-55 W 25-35 W 20-30
Olympics Ridgeline Winds (mph)
Thursday Evening WSW 15-25
Thursday Night W 10-20
Friday Morning W 10-20
Friday Afternoon WSW 5-15
West North Ridgeline Winds (mph)
Thursday Evening SSW 20-30
Thursday Night WSW 15-25
Friday Morning W 15-25
Friday Afternoon W 5-15
West Central Ridgeline Winds (mph)
Thursday Evening SW 20-30
Thursday Night W 15-25
Friday Morning W 15-25
Friday Afternoon W 5-15
West South Ridgeline Winds (mph)
Thursday Evening WSW 20-30
Thursday Night W 20-30
Friday Morning W 15-25
Friday Afternoon W 10-20
Stevens Pass Ridgeline Winds (mph)
Thursday Evening WSW 10-20
Thursday Night W 10-20
Friday Morning W 10-20
Friday Afternoon W 5-15
Snoqualmie Pass Ridgeline Winds (mph)
Thursday Evening WSW 20-30
Thursday Night W 15-25
Friday Morning W 15-25
Friday Afternoon W 15-25
East North Ridgeline Winds (mph)
Thursday Evening WSW 20-30
Thursday Night W 20-30
Friday Morning W 20-30
Friday Afternoon W 15-25
East Central Ridgeline Winds (mph)
Thursday Evening WSW 30-40
Thursday Night W 30-40
Friday Morning W 30-40
Friday Afternoon W 20-30
East South Ridgeline Winds (mph)
Thursday Evening WSW 30-40
Thursday Night W 35-50
Friday Morning W 30-40
Friday Afternoon W 20-30
Mt. Hood Ridgeline Winds (mph)
Thursday Evening WSW 30-40
Thursday Night W 40-55
Friday Morning W 25-35
Friday Afternoon W 20-30

Extended Weather Synopsis

The extended forecast begins in the middle of the 2nd of three atmospheric rivers forecasted to hit the Northwest over the next week. Widespread rain and very high elevation snow along with strong westerly winds should continue to impact the mountains Sunday night. As the firehose of precipitation shifts further south toward Oregon, slightly cooler air should enter the region allowing snow levels to slowly lower to around 5000-6500'. Some weather models draw additional moisture into this event, maintaining significant precipitation Sunday night and Monday. Others show a more steady decrease in shower activity. We'll have to wait and see how these two possibilities play out. 

 

Extended Snow Level (ft)

Saturday Night Sunday Sunday Night Monday *
West North 7500' 6000' 5500' 5500'
Snoqualmie Pass 8500' 7000' 6500' 6000'
Mt. Hood 8500' 7000' 6500' 6500'
West North Elevation
Saturday Night 7500'
Sunday 6000'
Sunday Night 5500'
Monday * 5500'
Snoqualmie Pass Elevation
Saturday Night 8500'
Sunday 7000'
Sunday Night 6500'
Monday * 6000'
Mt. Hood Elevation
Saturday Night 8500'
Sunday 7000'
Sunday Night 6500'
Monday * 6500'

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

Previous forecast from Nov 24, 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