Issued: 1:59 PM PST Monday, November 22, 2021
by Dennis D'Amico

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

Weather Synopsis

A weak frontal system will bring some light precipitation to the area Monday evening, passing through the Cascades after midnight. The trailing upper level trough will help invigorate shower activity late Monday night through much of Tuesday and usher in colder air.  The northwest Cascades including the Mt Baker area will be favored for more moderate precipitation at first, but after the trough's passage Tuesday morning, the flow will veer more WNW and shift the heavier precipitation into the central Cascades.  A convergence zone is likely to waffle from the Snoqualmie Pass area to Barlow Pass for much of Tuesday and help rack up additional inches of snowfall above 2000-2500'.  WNW ridgeline winds will be brisk in most areas on Tuesday. In total 4-12" seems likely along the west slopes of the Cascades and Mt Hood with 2-6" along the east slopes of the Cascades through Tuesday afternoon.  

A shortwave ridge will move over the area Tuesday night and Wednesday, with showers winding down Tuesday night.  Except for the far south Washington Cascades and Mt Hood, it looks unlikely we'll see much in the way of November sunshine on Wednesday before clouds from the next Pacific frontal system start moving inland. 

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 Cloudy with periods of light rain and snow, becoming steady light rain and snow around midnight.
Tuesday Mostly cloudy with scattered light rain and snow showers. Cooling trend.
Monday Night Periods of light rain and snow in the evening, becoming light to moderate after midnight.
Tuesday Cloudy with light to occasionally moderate rain and snow showers in the morning. Mostly cloudy with scattered light rain and snow showers in the afternoon. Cooling trend.
Monday Night Cloudy with periods of light rain and snow in the evening, becoming light to moderate after midnight.
Tuesday Light to occasionally moderate rain and snow showers in the morning, becoming mostly cloudy with scattered light snow showers in the afternoon. Windy. Cooling trend.
Monday Night Periods of light rain and snow in the evening, becoming light to moderate after late.
Tuesday Light to occasionally moderate rain and snow showers in the morning, becoming mostly cloudy with scattered light snow showers in the afternoon. Windy. Cooling trend.
Monday Night Cloudy with periods of light rain and snow in the evening, becoming light to moderate after midnight.
Tuesday Light to moderate rain and snow showers, becoming cloudy with scattered light to occasionally moderate snow showers in the afternoon. Windy. Cooling trend.
Monday Night Cloudy with periods of light rain and snow in the evening, becoming light to moderate after midnight.
Tuesday Light to moderate rain and snow showers, becoming cloudy with scattered light to occasionally moderate snow showers in the afternoon. Windy. Cooling trend.
Monday Night Cloudy with periods of light rain and snow in the evening, becoming steadier light rain and snow after midnight.
Tuesday Mostly cloudy with light rain and snow showers.
Monday Night Cloudy with periods of light rain and snow in the evening, becoming steadier light rain and snow late.
Tuesday Mostly cloudy with light rain and snow showers, occasionally moderate showers near the Cascade crest. Windy. Cooling trend.
Monday Night Cloudy with periods of light rain and snow in the evening, becoming steadier light rain and snow late.
Tuesday Mostly cloudy with light rain and snow showers, occasionally moderate showers near the Cascade crest in the morning. Windy. Cooling trend.
Monday Night Cloudy with periods of light rain and snow in the evening, becoming steadier light rain and snow late. Strong winds.
Tuesday Cloudy with light to occasionally moderate rain and snow showers, heaviest west side of Mt Hood. Windy. Cooling trend.

Precipitation (in)

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

Snow Level (ft)

Monday Evening Monday Night Tuesday Morning Tuesday Afternoon Tuesday Evening Tuesday Night Wednesday Morning Wednesday Afternoon
Olympics 3500' 3500' 2500' 2000' 2000' 2000' 3000' 3500'
West North 3500' 3500' 2500' 2000' 2000' 2000' 2500' 3000'
West Central 3500' 3500' 2500' 2000' 2000' 2000' 2500' 3000'
West South 4000' 4000' 3000' 2500' 2000' 2000' 2500' 3500'
Stevens Pass 3500' 3500' 2500' 2000' 2000' 2000' 2500' 3000'
Snoqualmie Pass 3500' 3500' 2500' 2000' 2000' 2000' 2500' 3000'
East North 3500' 2500' 3000' 4000' 2000' 1500' 2500' 3000'
East Central 4500' 4000' 3500' 3500' 2500' 2000' 2500' 3000'
East South 5500' 4000' 3500' 3500' 2500' 2000' 3000' 3500'
Mt. Hood 6500' 4000' 3500' 3500' 2500' 2000' 3500' 4500'
Olympics Elevation
Monday Evening 3500'
Monday Night 3500'
Tuesday Morning 2500'
Tuesday Afternoon 2000'
Tuesday Evening 2000'
Tuesday Night 2000'
Wednesday Morning 3000'
Wednesday Afternoon 3500'
West North Elevation
Monday Evening 3500'
Monday Night 3500'
Tuesday Morning 2500'
Tuesday Afternoon 2000'
Tuesday Evening 2000'
Tuesday Night 2000'
Wednesday Morning 2500'
Wednesday Afternoon 3000'
West Central Elevation
Monday Evening 3500'
Monday Night 3500'
Tuesday Morning 2500'
Tuesday Afternoon 2000'
Tuesday Evening 2000'
Tuesday Night 2000'
Wednesday Morning 2500'
Wednesday Afternoon 3000'
West South Elevation
Monday Evening 4000'
Monday Night 4000'
Tuesday Morning 3000'
Tuesday Afternoon 2500'
Tuesday Evening 2000'
Tuesday Night 2000'
Wednesday Morning 2500'
Wednesday Afternoon 3500'
Stevens Pass Elevation
Monday Evening 3500'
Monday Night 3500'
Tuesday Morning 2500'
Tuesday Afternoon 2000'
Tuesday Evening 2000'
Tuesday Night 2000'
Wednesday Morning 2500'
Wednesday Afternoon 3000'
Snoqualmie Pass Elevation
Monday Evening 3500'
Monday Night 3500'
Tuesday Morning 2500'
Tuesday Afternoon 2000'
Tuesday Evening 2000'
Tuesday Night 2000'
Wednesday Morning 2500'
Wednesday Afternoon 3000'
East North Elevation
Monday Evening 3500'
Monday Night 2500'
Tuesday Morning 3000'
Tuesday Afternoon 4000'
Tuesday Evening 2000'
Tuesday Night 1500'
Wednesday Morning 2500'
Wednesday Afternoon 3000'
East Central Elevation
Monday Evening 4500'
Monday Night 4000'
Tuesday Morning 3500'
Tuesday Afternoon 3500'
Tuesday Evening 2500'
Tuesday Night 2000'
Wednesday Morning 2500'
Wednesday Afternoon 3000'
East South Elevation
Monday Evening 5500'
Monday Night 4000'
Tuesday Morning 3500'
Tuesday Afternoon 3500'
Tuesday Evening 2500'
Tuesday Night 2000'
Wednesday Morning 3000'
Wednesday Afternoon 3500'
Mt. Hood Elevation
Monday Evening 6500'
Monday Night 4000'
Tuesday Morning 3500'
Tuesday Afternoon 3500'
Tuesday Evening 2500'
Tuesday Night 2000'
Wednesday Morning 3500'
Wednesday Afternoon 4500'

5000' Temperatures (°F)

Monday Night Tuesday
Max / Min Max / Min
Olympics 33 / 27 30 / 22
West North 32 / 28 29 / 21
West Central 34 / 29 28 / 22
West South 36 / 31 31 / 24
Stevens Pass 35 / 29 30 / 23
Snoqualmie Pass 36 / 30 31 / 23
East North 32 / 26 31 / 19
East Central 37 / 31 32 / 23
East South 39 / 32 33 / 25
Mt. Hood 40 / 34 37 / 27
Olympics 5000' Temperature Forecast
(Max / Min)
Monday Night 33 / 27
Tuesday 30 / 22
West North 5000' Temperature Forecast
(Max / Min)
Monday Night 32 / 28
Tuesday 29 / 21
West Central 5000' Temperature Forecast
(Max / Min)
Monday Night 34 / 29
Tuesday 28 / 22
West South 5000' Temperature Forecast
(Max / Min)
Monday Night 36 / 31
Tuesday 31 / 24
Stevens Pass 5000' Temperature Forecast
(Max / Min)
Monday Night 35 / 29
Tuesday 30 / 23
Snoqualmie Pass 5000' Temperature Forecast
(Max / Min)
Monday Night 36 / 30
Tuesday 31 / 23
East North 5000' Temperature Forecast
(Max / Min)
Monday Night 32 / 26
Tuesday 31 / 19
East Central 5000' Temperature Forecast
(Max / Min)
Monday Night 37 / 31
Tuesday 32 / 23
East South 5000' Temperature Forecast
(Max / Min)
Monday Night 39 / 32
Tuesday 33 / 25
Mt. Hood 5000' Temperature Forecast
(Max / Min)
Monday Night 40 / 34
Tuesday 37 / 27

Ridgeline Winds (mph)

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

Extended Weather Synopsis

A wet and increasingly warm pattern will take hold over the holiday weekend.  Warm frontal moisture is forecast to move over the Olympics and north Washington Cascades late Wednesday night and shift southward during Thanksgiving. The heaviest precipitation should reach all areas Thursday night before turning to a lighter more showery pattern (but still mild) on Friday.  We'll be on the south side of the jet stream for the duration of the event, with mild air working into the entire region eventually. While most areas will quickly transition to rain, significant snow could pile up in the northwest Cascades on Thanksgiving as snow levels rise during the day. The Washington Pass area and the northeast Cascades will likely see significant snowfall as well, with the warm-up delayed until Friday.  Mild and wet weather looks likely to continue through the holiday weekend with little chance of snow accumulating at mid and lower elevations through the extended. 

Extended Snow Level (ft)

Wednesday Night Thursday Thursday Night Friday
West North 2500' 4500' 6500' 6500'
Snoqualmie Pass 5000' 8000' 7000' 6500'
Mt. Hood 9000' 10000' 9000' 8000'
West North Elevation
Wednesday Night 2500'
Thursday 4500'
Thursday Night 6500'
Friday 6500'
Snoqualmie Pass Elevation
Wednesday Night 5000'
Thursday 8000'
Thursday Night 7000'
Friday 6500'
Mt. Hood Elevation
Wednesday Night 9000'
Thursday 10000'
Thursday Night 9000'
Friday 8000'

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

Previous forecast from Nov 21, 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