Issued: 2:15 PM PST Thursday, February 4, 2021
by Robert Hahn

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

Weather Synopsis

The Pacific Northwest remains sandwiched in an active pattern between a broad ridge of high pressure to our west and a cold trough over the center of the continent. An upper-level disturbance intensifies Thursday night as NW flow brings a plume of significant moisture into our region. Rain, snow, and wind should increase Thursday evening as the disturbance tightens pressure gradients and the jetstream sags southward from British Columbia toward our area. We expect heavy rain and snow for west slopes of the Cascades from highway 410 northward. Areas above 3500 ft can expect over a foot of snow in some areas. Milder air off the Pacific, brought in by the strong W low-level flow should raise snow levels to near or just above Snoqualmie Pass level. The milder air will compete with high precipitation rates which tend to lower the snow levels. Snow levels will fluctuate and Snoqualmie Pass could still get significant snow overnight. Crystal is situated on the north edge of a strong Mt. Rainier rain shadow. It is likely to pick up 4-6" of snow overnight, but uncertainty remains. Strong to extreme downslope winds intensify Friday night and peak in the early morning hours before gradually decreasing as the disturbance gradually relaxes on Friday. Snowfall should also taper throughout the day Friday.

Friday night features cooler temperatures and a relative break with some light snow showers.

Another disturbance moving into the region on NW flow should once again bring heavy rain and snow shifting from the northern parts of our region southward throughout the day Saturday. Strong to extreme downslope winds will once again develop along the east slopes and near the Cascade Crest, peaking late in the day or in the evening hours. After a cold start, snow levels may also rise above Snoqualmie Pass level in the afternoon.

On Friday, the pulse of energy shifts east of our region allowing snowfall to decrease from the moderate to the light range. Snow levels begin to drop toward the end of the day.

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
Thursday Night Light rain and snow. Moderate ridgeline winds may be strong at times after midnight. Strong ridgeline wind gusts.
Friday Light snow tapering off during the early morning hours then becoming mostly cloudy.
Thursday Night Heavy rain and snow. Moderate ridgeline winds with strong gusts.
Friday Light to moderate rain and snow decreasing rapidly and generally ending during the morning hours, then mostly cloudy in the afternoon.
Thursday Night Heavy rain and snow. Moderate ridgeline winds with strong gusts.
Friday Moderate rain and snow tapering to light showers by mid-morning. Strong ridgeline wind gusts in the morning.
Thursday Night Heavy rain and snow at Paradise and White Pass with moderate rain and snow at Crystal. Increasing moderate to occasionally strong ridgeline winds. Very strong to extreme ridgeline winds along the Cascade Crest such as White Pass.
Friday Heavy rain and snow will continue into the early morning hours at Paradise. Otherwise, light to moderate snow will transition to light showers by afternoon. Very strong to extreme ridgeline winds lingering into the early morning hours along the Cascade Crest such as White Pass, then gradually decreasing.
Thursday Night Heavy rain and snow. Light to moderate W wind at the Pass. Increasing moderate to strong ridgeline winds.
Friday Moderate rain and snow early tapering to light showers by the afternoon. Strong ridgeline wind gusts in the morning hours.
Thursday Night Heavy rain and snow. Snow levels near or slightly above the Pass. Increasing moderate W winds at the Pass. Moderate to occasionally strong ridgeline winds. Moderate to strong ridgeline winds. Moderate W winds at the Pass.
Friday Moderate to heavy rain and snow early tapering to light showers by the afternoon. Snow levels near or slightly above Pass level. Decreasing moderate to strong ridgeline winds. Decreasing moderate W winds at the Pass becoming light in the afternoon.
Thursday Night Moderate snow. Increasing moderate to strong ridgeline winds.
Friday Light to moderate snow early tapering to light showers by mid-morning. Becoming mostly cloudy in the afternoon. Strong ridgeline wind gusts possible in the early morning hours.
Thursday Night Moderate to heavy rain and snow becoming light further east. Strong ridgeline winds, likely very strong in the Wenatchee Mountains. Strong ridgeline winds becoming very strong to extreme in the Wenatchee mountains.
Friday Moderate rain and snow early tapering to light showers by mid-morning. Becoming mostly cloudy with very light snow showers near the Cascade Crest in the afternoon. Strong ridgeline winds becoming very strong to extreme in the Wenatchee mountains in the early morning hours then gradually decreasing.
Thursday Night Light rain and snow. Increasing moderate to strong ridgeline winds.
Friday Light to moderate rain and snow early tapering to light showers by mid-morning. Becoming mostly cloudy with very light snow showers near the Cascade Crest in the afternoon. Moderate to strong ridgeline winds becoming moderate by afternoon.
Thursday Night Increasing light snow. Increasing strong to very strong ridgeline winds with extreme gusts.
Friday Moderate rain and snow decreasing in the afternoon. Decreasing moderate to strong winds with very strong to extreme gusts.

Issued: 2:15 PM PST Thursday, February 4, 2021

Precipitation (in)

Thursday Night Friday Friday Night Saturday
4 pm - 4 am 4 am - 4 pm 4 pm - 4 am 4 am - 4 pm
Hurricane Ridge 0.25 LT 0.10 0 LT 0.25
Mt Baker Ski Area 1.00 LT 0.10 LT 0.10 0.50 - 0.75
Mt. Loop - Barlow Pass 1.00 - 1.50 0.25 LT 0.25 1.00
Stevens Pass 1.00 - 1.50 0.25 - 0.50 LT 0.10 0.75
Snoqualmie Pass 1.50 0.50 - 0.75 LT 0.25 0.75 -1.00
Crystal Mt 0.50 LT 0.25 LT 0.10 0.25
Paradise 1.00 - 1.50 0.75 LT 0.10 0.75
White Pass 0.75 -1.00 0.50 LT 0.10 0.50
Washington Pass 0.50 LT 0.25 LT 0.10 0.25
Mission Ridge LT 0.25 LT 0.10 0 LT 0.25
Salmon la Sac - Gallagher Head 0.75 -1.00 0.25 - 0.50 LT 0.10 0.50 - 0.75
Tieton River - Darland Mt. 0.25 LT 0.25 0 LT 0.25
Mt Hood Meadows 0.25 - 0.50 0.50 LT 0.10 0.25
Timberline 0.50 0.50 LT 0.10 0.25
Hurricane Ridge Precipitation (in)
Thursday Night 0.25
Friday LT 0.10
Friday Night 0
Saturday LT 0.25
Mt Baker Ski Area Precipitation (in)
Thursday Night 1.00
Friday LT 0.10
Friday Night LT 0.10
Saturday 0.50 - 0.75
Mt. Loop - Barlow Pass Precipitation (in)
Thursday Night 1.00 - 1.50
Friday 0.25
Friday Night LT 0.25
Saturday 1.00
Stevens Pass Precipitation (in)
Thursday Night 1.00 - 1.50
Friday 0.25 - 0.50
Friday Night LT 0.10
Saturday 0.75
Snoqualmie Pass Precipitation (in)
Thursday Night 1.50
Friday 0.50 - 0.75
Friday Night LT 0.25
Saturday 0.75 -1.00
Crystal Mt Precipitation (in)
Thursday Night 0.50
Friday LT 0.25
Friday Night LT 0.10
Saturday 0.25
Paradise Precipitation (in)
Thursday Night 1.00 - 1.50
Friday 0.75
Friday Night LT 0.10
Saturday 0.75
White Pass Precipitation (in)
Thursday Night 0.75 -1.00
Friday 0.50
Friday Night LT 0.10
Saturday 0.50
Washington Pass Precipitation (in)
Thursday Night 0.50
Friday LT 0.25
Friday Night LT 0.10
Saturday 0.25
Mission Ridge Precipitation (in)
Thursday Night LT 0.25
Friday LT 0.10
Friday Night 0
Saturday LT 0.25
Salmon la Sac - Gallagher Head Precipitation (in)
Thursday Night 0.75 -1.00
Friday 0.25 - 0.50
Friday Night LT 0.10
Saturday 0.50 - 0.75
Tieton River - Darland Mt. Precipitation (in)
Thursday Night 0.25
Friday LT 0.25
Friday Night 0
Saturday LT 0.25
Mt Hood Meadows Precipitation (in)
Thursday Night 0.25 - 0.50
Friday 0.50
Friday Night LT 0.10
Saturday 0.25
Timberline Precipitation (in)
Thursday Night 0.50
Friday 0.50
Friday Night LT 0.10
Saturday 0.25

Issued: 2:15 PM PST Thursday, February 4, 2021

Snow Level (ft)

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

Issued: 2:15 PM PST Thursday, February 4, 2021

5000' Temperatures (°F)

Thursday Night Friday
Max / Min Max / Min
Olympics 30 / 28 32 / 25
West North 29 / 26 29 / 26
West Central 28 / 26 28 / 27
West South 30 / 28 30 / 28
Stevens Pass 29 / 26 29 / 27
Snoqualmie Pass 29 / 27 29 / 28
East North 28 / 25 29 / 27
East Central 29 / 27 29 / 27
East South 30 / 27 32 / 27
Mt. Hood 29 / 27 33 / 28
Olympics 5000' Temperature Forecast
(Max / Min)
Thursday Night 30 / 28
Friday 32 / 25
West North 5000' Temperature Forecast
(Max / Min)
Thursday Night 29 / 26
Friday 29 / 26
West Central 5000' Temperature Forecast
(Max / Min)
Thursday Night 28 / 26
Friday 28 / 27
West South 5000' Temperature Forecast
(Max / Min)
Thursday Night 30 / 28
Friday 30 / 28
Stevens Pass 5000' Temperature Forecast
(Max / Min)
Thursday Night 29 / 26
Friday 29 / 27
Snoqualmie Pass 5000' Temperature Forecast
(Max / Min)
Thursday Night 29 / 27
Friday 29 / 28
East North 5000' Temperature Forecast
(Max / Min)
Thursday Night 28 / 25
Friday 29 / 27
East Central 5000' Temperature Forecast
(Max / Min)
Thursday Night 29 / 27
Friday 29 / 27
East South 5000' Temperature Forecast
(Max / Min)
Thursday Night 30 / 27
Friday 32 / 27
Mt. Hood 5000' Temperature Forecast
(Max / Min)
Thursday Night 29 / 27
Friday 33 / 28

Issued: 2:15 PM PST Thursday, February 4, 2021

Ridgeline Winds (mph)

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

Issued: 2:15 PM PST Thursday, February 4, 2021

Extended Weather Synopsis

Saturday night through Sunday night, NW flow maintains generally light mountain-enhanced snow and snow showers behind Saturday's disturbance. Expect some embedded convergence zone enhancement in the central Cascades. Snow should begin to ease on Sunday as a broad, cold trough over the center of the US and Canada edges westward into our area. Downslope winds will be at their maximum for the storm cycle Saturday night. Exposed ridgelines east of the Cascade crest could see winds in the 50-100 mph range before gradually easing Sunday and Sunday night.  Saturday night should start relatively mild, then expect strong cooling to bring temperatures below seasonal averages. Modified arctic air filters into the region on Monday. Temperatures at 5000 ft probably won't make it out of the teens.

Extended Snow Level (ft)

Saturday Night Sunday Sunday Night Monday
West North 2000' 1000' 500' 0
Snoqualmie Pass 2000' 1500' 1000' 500'
Mt. Hood 3000' 2000' 1500' 1000'
West North Elevation
Saturday Night 2000'
Sunday 1000'
Sunday Night 500'
Monday 0'
Snoqualmie Pass Elevation
Saturday Night 2000'
Sunday 1500'
Sunday Night 1000'
Monday 500'
Mt. Hood Elevation
Saturday Night 3000'
Sunday 2000'
Sunday Night 1500'
Monday 1000'

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

Previous forecast from Feb 4, 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’.