Issued: 2:18 PM PST Saturday, February 20, 2021
by Robert Hahn

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

Weather Synopsis

An atmospheric river event arrives Saturday night as a series an onslaught of moisture arrives on strong westerly flow. The leading edge of the moisture features a warm frontal passage late Saturday night along with increasing rain and snow throughout the region. Snow levels should rise, particularly after midnight.

Heavy rain and snow continue to focus on the west slopes of our mountains with milder conditions throughout the region on Sunday. Between 4 and 7 AM on Sunday morning, snow levels are expected to rise above Snoqualmie Pass and remain above pass level. Winds should continue to increase and will focus on the Cascade Crest, mountain gaps, and along the east slopes of the Cascades with strong downsloping.

Pressure gradients tighten further Sunday night as a cold front to our north slides down the British Columbia coastline. Winds should peak in the strong to very strong range in the previously described areas favored by the westerly flow. The northern Washington Cascades should experience the heaviest rain and snow of the event, while the southern Washington Cascades and Mt. Hood get slightly lighter precipitation.

The cold front passes through the region on Monday, bringing cooling temperatures and decreasing precipitation rates from NW to SE across the region during the day. However, Snoqualmie Pass proper may not see snow until Monday night.

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 Increasing light rain and snow.
Sunday Light rain and snow. Milder.
Saturday Night Increasing moderate rain and snow becoming heavy by morning.
Sunday Heavy rain and snow. Increasing moderate to strong ridgeline winds.
Saturday Night Increasing heavy rain and snow.
Sunday Heavy rain and snow. Increasing moderate to strong ridgeline winds.
Saturday Night Increasing moderate to heavy rain and snow at Paradise and White Pass; increasing light snow at Crystal. Strong ridgeline winds near the Cascade Crest.
Sunday Increasing heavy rain and snow at Paradise and White Pass; increasing light rain and snow at Crystal. Strong ridgeline winds with very strong winds near the Cascade Crest.
Saturday Night Increasing moderate rain and snow. Light to occasionally moderate W wind at the Pass.
Sunday Heavy rain and snow. Light to moderate W wind at the Pass. Increasing moderate to strong ridgeline winds.
Saturday Night Increasing heavy rain and snow. Light to moderate W wind at the Pass.
Sunday Heavy rain and snow. Moderate W wind at the Pass. Strong ridgeline winds.
Saturday Night Increasing light snow. Strong ridgeline wind gusts.
Sunday Light to moderate snow. Strong ridgeline wind gusts.
Saturday Night Increasing moderate rain and snow. Moderate to strong ridgeline winds.
Sunday Heavy rain and snow. Moderate to strong ridgeline winds.
Saturday Night Increasing light to moderate rain and snow.
Sunday Moderate rain and snow.
Saturday Night Increasing moderate rain and snow. Strong to very strong ridgeline winds.
Sunday Heavy rain and snow. Strong to very strong ridgeline winds.

Issued: 2:18 PM PST Saturday, February 20, 2021

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

Issued: 2:18 PM PST Saturday, February 20, 2021

Snow Level (ft)

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

Issued: 2:18 PM PST Saturday, February 20, 2021

5000' Temperatures (°F)

Saturday Night Sunday
Max / Min Max / Min
Olympics 28 / 22 32 / 29
Olympics 28 / 22 32 / 29
West North 25 / 20 30 / 26
West Central 26 / 22 30 / 26
West South 26 / 22 31 / 27
Stevens Pass 27 / 22 31 / 27
Snoqualmie Pass 27 / 21 31 / 27
East North 26 / 20 31 / 27
East South 24 / 21 32 / 24
Mt. Hood 25 / 22 32 / 25
Olympics 5000' Temperature Forecast
(Max / Min)
Saturday Night 28 / 22
Sunday 32 / 29
Olympics 5000' Temperature Forecast
(Max / Min)
Saturday Night 28 / 22
Sunday 32 / 29
West North 5000' Temperature Forecast
(Max / Min)
Saturday Night 25 / 20
Sunday 30 / 26
West Central 5000' Temperature Forecast
(Max / Min)
Saturday Night 26 / 22
Sunday 30 / 26
West South 5000' Temperature Forecast
(Max / Min)
Saturday Night 26 / 22
Sunday 31 / 27
Stevens Pass 5000' Temperature Forecast
(Max / Min)
Saturday Night 27 / 22
Sunday 31 / 27
Snoqualmie Pass 5000' Temperature Forecast
(Max / Min)
Saturday Night 27 / 21
Sunday 31 / 27
East North 5000' Temperature Forecast
(Max / Min)
Saturday Night 26 / 20
Sunday 31 / 27
East South 5000' Temperature Forecast
(Max / Min)
Saturday Night 24 / 21
Sunday 32 / 24
Mt. Hood 5000' Temperature Forecast
(Max / Min)
Saturday Night 25 / 22
Sunday 32 / 25

Issued: 2:18 PM PST Saturday, February 20, 2021

Ridgeline Winds (mph)

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

Issued: 2:18 PM PST Saturday, February 20, 2021

Extended Weather Synopsis

Snow production should be significant in post-frontal WNW flow behind Monday's cold front. Expect significant additional cooling Monday night with moderate snow through Tuesday across the west slopes of the Cascades. Convergence bands may focus locally heavy totals on portions of the central Washington Cascades. Tuesday night, the flow switches NNW. Snow showers gradually end from north to south as ridging builds offshore. Expect fair weather Wednesday morning, but another potent system approaches and may bring some light rain or snow to the Olympic Peninsula by the end of the day.

Extended Snow Level (ft)

Monday Night Tuesday Tuesday Night Wednesday
West North 1500' 1500' 500' 1000'
Snoqualmie Pass 2000' 1500' 1000' 1000'
Mt. Hood 3000' 2000' 1500' 1500'
West North Elevation
Monday Night 1500'
Tuesday 1500'
Tuesday Night 500'
Wednesday 1000'
Snoqualmie Pass Elevation
Monday Night 2000'
Tuesday 1500'
Tuesday Night 1000'
Wednesday 1000'
Mt. Hood Elevation
Monday Night 3000'
Tuesday 2000'
Tuesday Night 1500'
Wednesday 1500'

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

Previous forecast from Feb 20, 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’.