Issued: 2:09 PM PST Saturday, January 21, 2023
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 frontal system is sweeping through the Cascades early this afternoon with a burst of snow and wind.  The trailing low pressure center can be seen on radar/satellite with a distinct counter-clockwise swirl just south of the Olympic peninsula. This system has presented a few surprises and it's not done yet. With the front passing through this afternoon, the low pressure will track due westward this evening with NW flow in its wake Saturday night.  Post-frontal showers along with some convergence should be heaviest from about Snoqualmie Pass and south to Mt Hood. Precipitation amounts have been raised for southern areas and lowered for northern areas.  Mt St Helens, Paradise, Crystal Mt and Mt Hood may all end up with the highest snowfall amounts in this pattern. Also the strongest post-front winds have been somewhat muted this evening and then also nudged south overnight. The exception to the statement is the Mt Hood area which should see strong to extreme winds all night. 

On Sunday, showers and winds will taper down during the morning hours.  A few isolated showers may linger into the afternoon along the west slopes of the Cascades as well as broken low clouds near ridgetops. Sunnier skies can be found further east of the Cascade crest. Snow levels and temperatures will be in the 1500-2500' range on Sunday. 

Upper level ridging positioned offshore will battle a storm track aimed into central/northern British Columbia.  A weak upper trough may bring light snow to the Olympics and north Cascades for the first half of the day with lingering clouds in the afternoon.  You'll find diminishing cloud cover and warmer temperatues further south.  

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
Saturday Night Mostly cloudy with scattered light snow showers.
Sunday Cloudy with light snow showers in the morning, then mostly to partly cloudy with a chance of snow shower in the afternoon.
Saturday Night Cloudy with light to occasionally moderate snow showers in the evening, then scattered light snow showers overnight.
Sunday Cloudy with light snow showers in the morning, then mostly to partly cloudy with a chance of snow shower in the afternoon.
Saturday Night Cloudy with light to moderate snow showers. Moderate ridgeline winds.
Sunday Cloudy with light snow showers in the morning, then mostly cloudy with a chance of snow shower in the afternoon.
Saturday Night Cloudy with moderate snow showers. Moderate to strong ridgeline winds.
Sunday Cloudy with light snow showers in the morning, then mostly to partly cloudy with a chance of snow shower in the afternoon.
Saturday Night Cloudy with light to occasionally moderate snow showers. Moderate West Pass level and ridgeline winds.
Sunday Cloudy with light snow showers in the morning, then mostly to partly cloudy with a chance of snow shower in the afternoon. Light to moderate W-NW winds at Ridgeline and Pass level easing in the afternoon.
Saturday Night Cloudy with light to moderate snow showers. Moderate to strong West Pass level and ridgeline winds.
Sunday Cloudy with light snow showers in the morning, then mostly to partly cloudy with a chance of snow shower in the afternoon. Moderate W-NW winds at Ridgeline and Pass level easing in the afternoon.
Saturday Night Cloudy with occasional light snow showers. Moderate ridgeline winds.
Sunday Mostly cloudy with a chance of snow showers in the morning, becoming partly to mostly sunny in the afternoon. Sunnier further east of the Cascade crest.
Saturday Night Cloudy with light snow showers, except moderate near the Cascade crest. Moderate to strong ridgeline winds.
Sunday Mostly cloudy with a chance of snow showers in the morning, becoming partly to mostly sunny in the afternoon. Sunnier further east of the Cascade crest. Moderate ridgeline winds easing in the afternoon.
Saturday Night Cloudy with light snow showers, except moderate near the Cascade crest. Moderate to strong ridgeline winds.
Sunday Mostly cloudy with a chance of snow showers in the morning, becoming partly to mostly sunny in the afternoon. Sunnier further east of the Cascade crest. Moderate ridgeline winds easing in the afternoon.
Saturday Night Cloudy with moderate snow showers. Strong to extreme ridgeline winds.
Sunday Cloudy with light snow showers in the morning, then mostly to partly cloudy with a chance of snow shower in the afternoon.

Precipitation (in)

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

Snow Level (ft)

Saturday Evening Saturday Night Sunday Morning Sunday Afternoon Sunday Evening Sunday Night Monday Morning Monday Afternoon
Olympics 2000' 2000' 1500' 2000' 2500' 3500' 4000' 4500'
West North 2000' 2000' 1500' 1500' 1500' 1500' 2000' 2500'
West Central 2000' 2000' 1500' 1500' 1500' 1500' 2000' 3000'
West South 2000' 2000' 1500' 2000' 2000' 2000' 2500' 4000'
Stevens Pass 2000' 2000' 1500' 2000' 2000' 1500' 2000' 2500'
Snoqualmie Pass 2000' 2000' 1500' 2000' 2000' 2000' 2500' 3000'
East North 2000' 1500' 1500' 2000' 1500' 1500' 2000' 2500'
East Central 2000' 2000' 1500' 2000' 1500' 1500' 2000' 2500'
East South 2000' 2000' 1500' 2000' 2000' 2000' 3000' 4000'
Mt. Hood 2000' 2000' 1500' 2000' 2500' 3000' 4500' 7000'
Olympics Elevation
Saturday Evening 2000'
Saturday Night 2000'
Sunday Morning 1500'
Sunday Afternoon 2000'
Sunday Evening 2500'
Sunday Night 3500'
Monday Morning 4000'
Monday Afternoon 4500'
West North Elevation
Saturday Evening 2000'
Saturday Night 2000'
Sunday Morning 1500'
Sunday Afternoon 1500'
Sunday Evening 1500'
Sunday Night 1500'
Monday Morning 2000'
Monday Afternoon 2500'
West Central Elevation
Saturday Evening 2000'
Saturday Night 2000'
Sunday Morning 1500'
Sunday Afternoon 1500'
Sunday Evening 1500'
Sunday Night 1500'
Monday Morning 2000'
Monday Afternoon 3000'
West South Elevation
Saturday Evening 2000'
Saturday Night 2000'
Sunday Morning 1500'
Sunday Afternoon 2000'
Sunday Evening 2000'
Sunday Night 2000'
Monday Morning 2500'
Monday Afternoon 4000'
Stevens Pass Elevation
Saturday Evening 2000'
Saturday Night 2000'
Sunday Morning 1500'
Sunday Afternoon 2000'
Sunday Evening 2000'
Sunday Night 1500'
Monday Morning 2000'
Monday Afternoon 2500'
Snoqualmie Pass Elevation
Saturday Evening 2000'
Saturday Night 2000'
Sunday Morning 1500'
Sunday Afternoon 2000'
Sunday Evening 2000'
Sunday Night 2000'
Monday Morning 2500'
Monday Afternoon 3000'
East North Elevation
Saturday Evening 2000'
Saturday Night 1500'
Sunday Morning 1500'
Sunday Afternoon 2000'
Sunday Evening 1500'
Sunday Night 1500'
Monday Morning 2000'
Monday Afternoon 2500'
East Central Elevation
Saturday Evening 2000'
Saturday Night 2000'
Sunday Morning 1500'
Sunday Afternoon 2000'
Sunday Evening 1500'
Sunday Night 1500'
Monday Morning 2000'
Monday Afternoon 2500'
East South Elevation
Saturday Evening 2000'
Saturday Night 2000'
Sunday Morning 1500'
Sunday Afternoon 2000'
Sunday Evening 2000'
Sunday Night 2000'
Monday Morning 3000'
Monday Afternoon 4000'
Mt. Hood Elevation
Saturday Evening 2000'
Saturday Night 2000'
Sunday Morning 1500'
Sunday Afternoon 2000'
Sunday Evening 2500'
Sunday Night 3000'
Monday Morning 4500'
Monday Afternoon 7000'

5000' Temperatures (°F)

Saturday Night Sunday
Max / Min Max / Min
Olympics 24 / 14 25 / 14
West North 23 / 19 21 / 18
West Central 23 / 21 21 / 18
West South 24 / 21 24 / 19
Stevens Pass 22 / 18 22 / 19
Snoqualmie Pass 22 / 20 21 / 17
East North 20 / 15 25 / 19
East Central 21 / 18 25 / 20
East South 24 / 20 27 / 19
Mt. Hood 22 / 20 26 / 19
Olympics 5000' Temperature Forecast
(Max / Min)
Saturday Night 24 / 14
Sunday 25 / 14
West North 5000' Temperature Forecast
(Max / Min)
Saturday Night 23 / 19
Sunday 21 / 18
West Central 5000' Temperature Forecast
(Max / Min)
Saturday Night 23 / 21
Sunday 21 / 18
West South 5000' Temperature Forecast
(Max / Min)
Saturday Night 24 / 21
Sunday 24 / 19
Stevens Pass 5000' Temperature Forecast
(Max / Min)
Saturday Night 22 / 18
Sunday 22 / 19
Snoqualmie Pass 5000' Temperature Forecast
(Max / Min)
Saturday Night 22 / 20
Sunday 21 / 17
East North 5000' Temperature Forecast
(Max / Min)
Saturday Night 20 / 15
Sunday 25 / 19
East Central 5000' Temperature Forecast
(Max / Min)
Saturday Night 21 / 18
Sunday 25 / 20
East South 5000' Temperature Forecast
(Max / Min)
Saturday Night 24 / 20
Sunday 27 / 19
Mt. Hood 5000' Temperature Forecast
(Max / Min)
Saturday Night 22 / 20
Sunday 26 / 19

Ridgeline Winds (mph)

Saturday Evening Saturday Night Sunday Morning Sunday Afternoon
Olympics NW 10-20 WNW 10-20 NW 5-15 NW 5-15
West North W 10-20 WNW 5-15 W 5-15 W 0-10
West Central WSW 15-25 WNW 15-25 NW 10-20 NW 5-15
West South W 20-30 NW 15-25 NW 10-20 NW 5-15
Stevens Pass W 10-20 WNW 15-25 NW 10-20 NW 5-15
Snoqualmie Pass W 15-25 NW 20-30 NW 15-25 NW 10-20
East North W 10-20 NW 10-20 NW 10-20 NW 5-15
East Central W 15-25 WNW 20-30 NW 15-25 NW 10-20
East South W 20-30 WNW 20-30 NW 15-25 NW 10-20
Mt. Hood W 30-40 WNW 35-50 NW 20-30 NW 10-20
Olympics Ridgeline Winds (mph)
Saturday Evening NW 10-20
Saturday Night WNW 10-20
Sunday Morning NW 5-15
Sunday Afternoon NW 5-15
West North Ridgeline Winds (mph)
Saturday Evening W 10-20
Saturday Night WNW 5-15
Sunday Morning W 5-15
Sunday Afternoon W 0-10
West Central Ridgeline Winds (mph)
Saturday Evening WSW 15-25
Saturday Night WNW 15-25
Sunday Morning NW 10-20
Sunday Afternoon NW 5-15
West South Ridgeline Winds (mph)
Saturday Evening W 20-30
Saturday Night NW 15-25
Sunday Morning NW 10-20
Sunday Afternoon NW 5-15
Stevens Pass Ridgeline Winds (mph)
Saturday Evening W 10-20
Saturday Night WNW 15-25
Sunday Morning NW 10-20
Sunday Afternoon NW 5-15
Snoqualmie Pass Ridgeline Winds (mph)
Saturday Evening W 15-25
Saturday Night NW 20-30
Sunday Morning NW 15-25
Sunday Afternoon NW 10-20
East North Ridgeline Winds (mph)
Saturday Evening W 10-20
Saturday Night NW 10-20
Sunday Morning NW 10-20
Sunday Afternoon NW 5-15
East Central Ridgeline Winds (mph)
Saturday Evening W 15-25
Saturday Night WNW 20-30
Sunday Morning NW 15-25
Sunday Afternoon NW 10-20
East South Ridgeline Winds (mph)
Saturday Evening W 20-30
Saturday Night WNW 20-30
Sunday Morning NW 15-25
Sunday Afternoon NW 10-20
Mt. Hood Ridgeline Winds (mph)
Saturday Evening W 30-40
Saturday Night WNW 35-50
Sunday Morning NW 20-30
Sunday Afternoon NW 10-20

Extended Weather Synopsis

The same pattern described on Monday with flat upper level ridging that allows clouds and periods of light snow to the north and milder and fewer clouds to the south will apply Monday night and Tuesday.  On Tuesday night, upper level ridging will amplify offshore, leaving to mild and sunny day on Wednesday. 

Extended Snow Level (ft)

Monday Night Tuesday Tuesday Night Wednesday
West North 2000' 2000' 2500' 7000'
Snoqualmie Pass 2500' 2500' 3000' 7000'
Mt. Hood 6500' 4500' 4500' 7000'
West North Elevation
Monday Night 2000'
Tuesday 2000'
Tuesday Night 2500'
Wednesday 7000'
Snoqualmie Pass Elevation
Monday Night 2500'
Tuesday 2500'
Tuesday Night 3000'
Wednesday 7000'
Mt. Hood Elevation
Monday Night 6500'
Tuesday 4500'
Tuesday Night 4500'
Wednesday 7000'

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

Previous forecast from Jan 21, 2023

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