Issued: 1:59 PM PST Friday, February 19, 2021
by Dallas Glass

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

Weather Synopsis

A trough passing over the Pacific Northwest should maintain scattered snow showers in the mountains overnight and into Saturday. While accumulations appear light, some trailheads could receive a few inches of snow, especially near a weak Puget Sound Convergence Zone focused between the Mountain Loop and Hwy 2 areas. Look for ridgetop winds to begin to increase throughout the short-term forecast as the trough exists and the jet stream passes over the region. On Saturday expect partly to mostly cloudy skies, brief sun breaks, and occasional snow showers for most of our mountain areas. 

The weather really begins to change Saturday night into Sunday as warming temperatures, moderate to heavy precipitation, and very strong winds impact the entire forecast area. An atmospheric river event tied to a strong jet stream will take aim at the British Columbia coast late Saturday. As it does, you may notice the snowline slowly creeping up the mountainside overnight. A large pulse of warmer air appears to quickly swing into the area Sunday morning with a rapid rise in temperatures and brings rain above pass levels. Temperatures should continue to warm with snow levels peaking sometime Sunday night or Monday. As the jet stream begins to sag south, precipitation in the Olympics and Cascades will dramatically increase. Expect periods of heavy rain and snow in most mountain locations accompanied by strong ridgetop winds. The atmospheric river takes aim at Washington as we head into the extended forecast period. 

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
Friday Night Mostly cloudy with isolated snow showers.
Saturday Partly to mostly cloudy. Isolated flurries possible.
Friday Night Cloudy with scattered snow showers. W winds increasing.
Saturday Mostly cloudy with isolated snow showers. W winds increasing in the afternoon.
Friday Night Cloudy with scattered showers. Weak convergence zone possible near Hwy 2. W winds increasing.
Saturday Mostly cloudy with isolated snow showers.
Friday Night Mostly cloudy to cloudy. Isolated snowers. W winds increasing.
Saturday Partly to mostly cloudy. Isolated snow showers. W winds becoming strong
Friday Night Cloudy with a weak convergence zone possible. W winds increasing.
Saturday Mostly cloudy with some sun breaks. Scattered showers. W winds becoming strong.
Friday Night Mostly cloudy with scattered showers. W winds becoming strong.
Saturday Mostly cloudy with a few sun breaks possible. Scattered showers. Strong W winds.
Friday Night Mostly cloudy with isolated showers.
Saturday Partly to mostly cloudy with isolated showers. WNW winds increasing.
Friday Night Partly to mostly cloudy. Isolated showers near the crest. W winds becoming strong.
Saturday Partly to mostly cloudy. Isolated showers near the crest. Strong W winds.
Friday Night Partly to mostly cloudy. Isolated showers near the crest. W winds increasing.
Saturday Partly to mostly cloudy. Isolated showers near the crest. Moderate to strong W winds.
Friday Night Mostly cloudy with scattered snow showers.
Saturday Mostly cloudy with sun breaks possible. Scattered shower. W winds becoming strong.

Precipitation (in)

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

Snow Level (ft)

Friday Evening Friday Night Saturday Morning Saturday Afternoon Saturday Evening Saturday Night Sunday Morning Sunday Afternoon
Olympics 2500' 2000' 2000' 2500' 2000' 3000' 4500' 5000'
West North 1500' 1500' 1500' 2000' 1500' 2000' 3000' 4000'
West Central 2000' 2000' 2000' 2500' 2000' 2500' 3500' 4500'
West South 2500' 2000' 2000' 2500' 2000' 3000' 4000' 5000'
Stevens Pass 2000' 2000' 1500' 2500' 2000' 2500' 3500' 4500'
Snoqualmie Pass 2500' 2000' 2000' 2500' 2000' 2500' 4000' 5000'
East North 1000' 1000' 1000' 2000' 1000' 1500' 2500' 3500'
East Central 1500' 1000' 1500' 2500' 1500' 2000' 3000' 4500'
East South 2000' 1000' 1500' 2500' 2000' 2000' 3500' 4500'
Mt. Hood 2500' 2000' 2000' 2500' 2500' 2500' 3500' 5000'
Olympics Elevation
Friday Evening 2500'
Friday Night 2000'
Saturday Morning 2000'
Saturday Afternoon 2500'
Saturday Evening 2000'
Saturday Night 3000'
Sunday Morning 4500'
Sunday Afternoon 5000'
West North Elevation
Friday Evening 1500'
Friday Night 1500'
Saturday Morning 1500'
Saturday Afternoon 2000'
Saturday Evening 1500'
Saturday Night 2000'
Sunday Morning 3000'
Sunday Afternoon 4000'
West Central Elevation
Friday Evening 2000'
Friday Night 2000'
Saturday Morning 2000'
Saturday Afternoon 2500'
Saturday Evening 2000'
Saturday Night 2500'
Sunday Morning 3500'
Sunday Afternoon 4500'
West South Elevation
Friday Evening 2500'
Friday Night 2000'
Saturday Morning 2000'
Saturday Afternoon 2500'
Saturday Evening 2000'
Saturday Night 3000'
Sunday Morning 4000'
Sunday Afternoon 5000'
Stevens Pass Elevation
Friday Evening 2000'
Friday Night 2000'
Saturday Morning 1500'
Saturday Afternoon 2500'
Saturday Evening 2000'
Saturday Night 2500'
Sunday Morning 3500'
Sunday Afternoon 4500'
Snoqualmie Pass Elevation
Friday Evening 2500'
Friday Night 2000'
Saturday Morning 2000'
Saturday Afternoon 2500'
Saturday Evening 2000'
Saturday Night 2500'
Sunday Morning 4000'
Sunday Afternoon 5000'
East North Elevation
Friday Evening 1000'
Friday Night 1000'
Saturday Morning 1000'
Saturday Afternoon 2000'
Saturday Evening 1000'
Saturday Night 1500'
Sunday Morning 2500'
Sunday Afternoon 3500'
East Central Elevation
Friday Evening 1500'
Friday Night 1000'
Saturday Morning 1500'
Saturday Afternoon 2500'
Saturday Evening 1500'
Saturday Night 2000'
Sunday Morning 3000'
Sunday Afternoon 4500'
East South Elevation
Friday Evening 2000'
Friday Night 1000'
Saturday Morning 1500'
Saturday Afternoon 2500'
Saturday Evening 2000'
Saturday Night 2000'
Sunday Morning 3500'
Sunday Afternoon 4500'
Mt. Hood Elevation
Friday Evening 2500'
Friday Night 2000'
Saturday Morning 2000'
Saturday Afternoon 2500'
Saturday Evening 2500'
Saturday Night 2500'
Sunday Morning 3500'
Sunday Afternoon 5000'

5000' Temperatures (°F)

Friday Night Saturday
Max / Min Max / Min
Olympics 22 / 16 24 / 17
West North 21 / 17 22 / 17
West Central 22 / 19 22 / 19
West South 24 / 19 25 / 18
Stevens Pass 22 / 20 23 / 20
Snoqualmie Pass 22 / 20 23 / 19
East North 20 / 16 25 / 16
East Central 22 / 18 24 / 18
East South 23 / 18 26 / 17
Mt. Hood 25 / 19 25 / 20
Olympics 5000' Temperature Forecast
(Max / Min)
Friday 4pm - 4am 22 / 16
Saturday 4am - 4pm 24 / 17
West North 5000' Temperature Forecast
(Max / Min)
Friday 4pm - 4am 21 / 17
Saturday 4am - 4pm 22 / 17
West Central 5000' Temperature Forecast
(Max / Min)
Friday 4pm - 4am 22 / 19
Saturday 4am - 4pm 22 / 19
West South 5000' Temperature Forecast
(Max / Min)
Friday 4pm - 4am 24 / 19
Saturday 4am - 4pm 25 / 18
Stevens Pass 5000' Temperature Forecast
(Max / Min)
Friday 4pm - 4am 22 / 20
Saturday 4am - 4pm 23 / 20
Snoqualmie Pass 5000' Temperature Forecast
(Max / Min)
Friday 4pm - 4am 22 / 20
Saturday 4am - 4pm 23 / 19
East North 5000' Temperature Forecast
(Max / Min)
Friday 4pm - 4am 20 / 16
Saturday 4am - 4pm 25 / 16
East Central 5000' Temperature Forecast
(Max / Min)
Friday 4pm - 4am 22 / 18
Saturday 4am - 4pm 24 / 18
East South 5000' Temperature Forecast
(Max / Min)
Friday 4pm - 4am 23 / 18
Saturday 4am - 4pm 26 / 17
Mt. Hood 5000' Temperature Forecast
(Max / Min)
Friday 4pm - 4am 25 / 19
Saturday 4am - 4pm 25 / 20

Ridgeline Winds (mph)

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

Extended Weather Synopsis

The brunt of this atmospheric river event appears to occur Sunday night into Monday morning as a strong jet stream and deep sub-tropical moisture tap bare down on the Pacific Northwest. Snow levels should peak early Monday between 4500 and 6000ft. Many of our mountain locations could receive several inches of total precipitation before this event winds down. A building high-pressure ridge in the eastern Pacific eventually breaks the flow of moisture into the atmospheric river Monday night and turns our prevailing winds northwesterly. This should quickly usher in much colder air, drop snow levels, and returning snow to all trailhead locations. 

Extended Snow Level (ft)

Sunday Night Monday Monday Night Tuesday
West North 4000' 4500' 1000' 1000'
Snoqualmie Pass 5000' 5500' 1500' 1500'
Mt. Hood 5500' 6000' 2000' 2000'
West North Elevation
Sunday Night 4000'
Monday 4500'
Monday Night 1000'
Tuesday 1000'
Snoqualmie Pass Elevation
Sunday Night 5000'
Monday 5500'
Monday Night 1500'
Tuesday 1500'
Mt. Hood Elevation
Sunday Night 5500'
Monday 6000'
Monday Night 2000'
Tuesday 2000'

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

Previous forecast from Feb 19, 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