Issued: 7:08 AM PST Monday, February 22, 2021
by Robert Hahn

Jump to: Weather Forecast I Snow Level I Precipitation I Ridgeline Winds I

Weather Synopsis

High to extreme avalanche danger exists in the mountains. Please check the avalanche forecast before traveling to or recreating in the mountains.

The atmospheric river impacting our region continues to deal our region its most powerful impacts throughout the day on Monday. Satellite imagery early Monday morning shows a stream of moisture originating west of the Hawaiian Islands that feeds moisture into our region. Very heavy rain and snow developed Sunday night and should continue from the mountain loop area southward. A cold front drops SE across Washington state today. In advance of it, precipitation rates of 0.1-0.25" per hour are expected through around 3 PM in the central Washington Cascades and should extend into the evening hours for Mt. Hood. Mt. Baker may get some light to moderate precipitation as rain and snow spill slightly back northward into the area before the front moves through. Very strong downslope winds continue in favored areas along the east slopes of the Cascades.

Moderate showers, heavy convergence activity, and rapidly cooling temperatures will be the story Monday night. Convergence appears to focus on areas from the mountain loop to just north of Snoqualmie Pass and the Salmon La Sac region. With rapidly increasing snow water ratios, this could result in over a foot of fresh snow overnight in some parts of the central Washington Cascades.

On Tuesday, a shortwave trough approaches and should bring slightly more convective snow showers with more convergence, potentially focusing slightly southward into the Snoqualmie Pass area. Another foot of snow is possible in areas favored by convergence with snow levels around 1000-2000 ft.

 

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 Light to moderate rain and snow tapering to light showers.
Monday Night Light snow showers.
Monday Light to moderate rain and snow increasing during the mid-day hours and becoming showery in the afternoon.
Monday Night Light to occasionally moderate snow showers, heaviest southern part.
Monday Very heavy rain and snow becoming heavy showers and convergence late in the day.
Monday Night Moderate snow showers, heavy in convergence bands. Moderate to strong ridgeline winds.
Monday Very heavy rain and snow at Paradise, heavy rain and snow at White Pass, and moderate to heavy rain and snow at Crystal. Moderate ridgeline winds in most areas, but expect strong to very strong ridgeline winds near the Cascade Crest and White Pass.
Monday Night Light to moderate rain and snow showers changing to all snow showers.
Monday Very heavy rain and snow becoming heavy showers and convergence late in the day. Increasing light W winds at the Pass. Moderate ridgeline winds with strong gusts.
Monday Night Moderate snow showers with heavy convergence likely at times. Light to moderate W winds at the Pass. Moderate to strong ridgeline winds.
Monday Very heavy rain and snow. Light to moderate W winds at the Pass. Moderate to strong ridgeline winds.
Monday Night Moderate snow showers with heavy convergence likely at times. Moderate W winds at the Pass. Moderate to strong ridgeline winds.
Monday Moderate to heavy rain and snow becoming showery late in the day.
Monday Night Light snow showers.
Monday Very heavy rain and snow with strong ridgeline winds, western part. Moderate to heavy rain and snow with very strong to extreme ridgeline winds, eastern part.
Monday Night Moderate rain and snow showers, locally heavy in convergence bands and strong winds, western part. Light rain and snow showers with strong to very strong ridgeline winds, eastern part.
Monday Heavy rain and snow. Moderate to strong ridgeline winds.
Monday Night Light to moderate rain and snow showers changing to all snow showers.
Monday Heavy rain and snow. Very strong ridgeline winds.
Monday Night Heavy rain and snow in the early tapering to light to moderate snow showers. Strong ridgeline winds.

Precipitation (in)

Monday Monday Night Tuesday
4 am - 4 pm 4 pm - 4 am 4 am - 4 pm
Hurricane Ridge 0.25 - 0.50 LT 0.25 0.25
Mt Baker Ski Area 0.50 0.25 0.25
Mt. Loop - Barlow Pass 1.50 - 2.00 0.50 0.75
Stevens Pass 1.50 - 2.00 0.50 0.50
Snoqualmie Pass 2.00 - 2.50 0.50 0.75
Crystal Mt 0.75 0.25 0.25
Paradise 2.00 0.25 - 0.50 0.50
White Pass 1.00 - 1.50 0.25 - 0.50 0.25 - 0.50
Washington Pass 0.75 0.25 0.25
Mission Ridge 0.75 0.25 LT 0.10
Salmon la Sac - Gallagher Head 1.50 - 2.00 0.50 - 0.75 0.50 - 0.75
Tieton River - Darland Mt. 1.00 0.25 - 0.50 LT 0.25
Mt Hood Meadows 1.00 - 1.50 0.50 0.25
Timberline 1.00 - 1.50 0.50 0.25
Hurricane Ridge Precipitation (in)
Monday 0.25 - 0.50
Monday Night LT 0.25
Tuesday 0.25
Mt Baker Ski Area Precipitation (in)
Monday 0.50
Monday Night 0.25
Tuesday 0.25
Mt. Loop - Barlow Pass Precipitation (in)
Monday 1.50 - 2.00
Monday Night 0.50
Tuesday 0.75
Stevens Pass Precipitation (in)
Monday 1.50 - 2.00
Monday Night 0.50
Tuesday 0.50
Snoqualmie Pass Precipitation (in)
Monday 2.00 - 2.50
Monday Night 0.50
Tuesday 0.75
Crystal Mt Precipitation (in)
Monday 0.75
Monday Night 0.25
Tuesday 0.25
Paradise Precipitation (in)
Monday 2.00
Monday Night 0.25 - 0.50
Tuesday 0.50
White Pass Precipitation (in)
Monday 1.00 - 1.50
Monday Night 0.25 - 0.50
Tuesday 0.25 - 0.50
Washington Pass Precipitation (in)
Monday 0.75
Monday Night 0.25
Tuesday 0.25
Mission Ridge Precipitation (in)
Monday 0.75
Monday Night 0.25
Tuesday LT 0.10
Salmon la Sac - Gallagher Head Precipitation (in)
Monday 1.50 - 2.00
Monday Night 0.50 - 0.75
Tuesday 0.50 - 0.75
Tieton River - Darland Mt. Precipitation (in)
Monday 1.00
Monday Night 0.25 - 0.50
Tuesday LT 0.25
Mt Hood Meadows Precipitation (in)
Monday 1.00 - 1.50
Monday Night 0.50
Tuesday 0.25
Timberline Precipitation (in)
Monday 1.00 - 1.50
Monday Night 0.50
Tuesday 0.25

Snow Level (ft)

Monday Morning Monday Afternoon Monday Evening Monday Night Tuesday Morning Tuesday Afternoon
Olympics 5000' 4000' 2500' 1500' 1500' 1500'
West North 4500' 3500' 2500' 1000' 500' 1500'
West Central 4500' 4000' 3000' 1500' 1000' 1500'
West South 5000' 5000' 3500' 1500' 1000' 2000'
Stevens Pass 4500' 4000' 3500' 1500' 1000' 2000'
Snoqualmie Pass 5000' 4500' 4000' 2000' 1500' 2000'
East North 4500' 4500' 3000' 1000' 0 2000'
East Central 5000' 4500' 3500' 2000' 1000' 2000'
East South 6000' 5000' 4000' 2000' 1000' 2000'
Mt. Hood 6000' 6000' 5500' 2000' 1500' 2000'
Olympics Elevation
Monday Morning 5000'
Monday Afternoon 4000'
Monday Evening 2500'
Monday Night 1500'
Tuesday Morning 1500'
Tuesday Afternoon 1500'
West North Elevation
Monday Morning 4500'
Monday Afternoon 3500'
Monday Evening 2500'
Monday Night 1000'
Tuesday Morning 500'
Tuesday Afternoon 1500'
West Central Elevation
Monday Morning 4500'
Monday Afternoon 4000'
Monday Evening 3000'
Monday Night 1500'
Tuesday Morning 1000'
Tuesday Afternoon 1500'
West South Elevation
Monday Morning 5000'
Monday Afternoon 5000'
Monday Evening 3500'
Monday Night 1500'
Tuesday Morning 1000'
Tuesday Afternoon 2000'
Stevens Pass Elevation
Monday Morning 4500'
Monday Afternoon 4000'
Monday Evening 3500'
Monday Night 1500'
Tuesday Morning 1000'
Tuesday Afternoon 2000'
Snoqualmie Pass Elevation
Monday Morning 5000'
Monday Afternoon 4500'
Monday Evening 4000'
Monday Night 2000'
Tuesday Morning 1500'
Tuesday Afternoon 2000'
East North Elevation
Monday Morning 4500'
Monday Afternoon 4500'
Monday Evening 3000'
Monday Night 1000'
Tuesday Morning 0'
Tuesday Afternoon 2000'
East Central Elevation
Monday Morning 5000'
Monday Afternoon 4500'
Monday Evening 3500'
Monday Night 2000'
Tuesday Morning 1000'
Tuesday Afternoon 2000'
East South Elevation
Monday Morning 6000'
Monday Afternoon 5000'
Monday Evening 4000'
Monday Night 2000'
Tuesday Morning 1000'
Tuesday Afternoon 2000'
Mt. Hood Elevation
Monday Morning 6000'
Monday Afternoon 6000'
Monday Evening 5500'
Monday Night 2000'
Tuesday Morning 1500'
Tuesday Afternoon 2000'

5000' Temperatures (°F)

Monday Monday Night
Max / Min Max / Min
Olympics 32 / 26 23 / 19
West North 32 / 25 24 / 19
West Central 31 / 27 25 / 19
West South 32 / 31 30 / 20
Stevens Pass 32 / 31 27 / 19
Snoqualmie Pass 32 / 31 28 / 20
East North 33 / 28 24 / 18
East Central 33 / 31 29 / 18
East South 34 / 32 32 / 19
Mt. Hood 35 / 33 33 / 20
Olympics 5000' Temperature Forecast
(Max / Min)
Monday 4am - 4pm 32 / 26
Monday 4pm - 4am 23 / 19
West North 5000' Temperature Forecast
(Max / Min)
Monday 4am - 4pm 32 / 25
Monday 4pm - 4am 24 / 19
West Central 5000' Temperature Forecast
(Max / Min)
Monday 4am - 4pm 31 / 27
Monday 4pm - 4am 25 / 19
West South 5000' Temperature Forecast
(Max / Min)
Monday 4am - 4pm 32 / 31
Monday 4pm - 4am 30 / 20
Stevens Pass 5000' Temperature Forecast
(Max / Min)
Monday 4am - 4pm 32 / 31
Monday 4pm - 4am 27 / 19
Snoqualmie Pass 5000' Temperature Forecast
(Max / Min)
Monday 4am - 4pm 32 / 31
Monday 4pm - 4am 28 / 20
East North 5000' Temperature Forecast
(Max / Min)
Monday 4am - 4pm 33 / 28
Monday 4pm - 4am 24 / 18
East Central 5000' Temperature Forecast
(Max / Min)
Monday 4am - 4pm 33 / 31
Monday 4pm - 4am 29 / 18
East South 5000' Temperature Forecast
(Max / Min)
Monday 4am - 4pm 34 / 32
Monday 4pm - 4am 32 / 19
Mt. Hood 5000' Temperature Forecast
(Max / Min)
Monday 4am - 4pm 35 / 33
Monday 4pm - 4am 33 / 20

Ridgeline Winds (mph)

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

Jump to: Weather Forecast I Snow Level I Precipitation I Ridgeline Winds I

Previous forecast from Feb 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