Issued: 2:10 PM PST Friday, February 12, 2021
by Robert Hahn

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

Weather Synopsis

A strengthening low and associated trough approach the Olympic coastline Friday night. The storm moves into a modified arctic air mass. Expect sub-zero wind chills as easterly winds increase and peak overnight or early Saturday morning. The driving forces behind these winds include the dense cold air east of the Cascades and a low pressure offshore pulling that air toward it. A band of moderate snowfall (over the lowlands and mountains) should continue to tap into increased moisture as the system approaches and may become heavy from the Mt. Rainier area to Mt. Hood. Lighter snow should also expand northward to the Canadian border by Saturday morning.

The low-pressure arrives Saturday and weakens as it moves onshore. Expect flow wrapping around the low to maintain heavier snow in the southern parts of the forecast area. Across the region, the snow should ease during the afternoon.

Shortwave features should maintain periods of light snowfall along the western slopes of the Cascades and Olympics Saturday night and Sunday.

Snow levels should remain near sea level throughout the period with a very gradual moderation of temperatures and rain possible in the lowlands by Sunday afternoon.

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 Cold. Increasing light to moderate snow developing after midnight.
Saturday Cold. Decreasing light to moderate snow tapering to flurries late in the day.
Friday Night Cold. Cloudy with light snow developing in the early morning hours.
Saturday Cold. Light snow.
Friday Night Cold. Cloudy with light snow developing in the early morning hours.
Saturday Cold. Light snow north, of highway 2, moderate snow south of highway 2.
Friday Night Cold. Moderate to heavy snow at Paradise; moderate snow at White Pass and Crystal.
Saturday Cold. Heavy snow at Paradise, moderate to heavy snow at White Pass, light to moderate snow at Crystal.
Friday Night Cold. Cloudy in the evening with light snow developing. Light to occasionally moderate E winds at the Pass.
Saturday Cold. Light snow. Decreasing light to occasionally moderate E winds at the Pass.
Friday Night Cold. Increasing light snow becoming moderate by morning. Moderate E winds at the Pass.
Saturday Cold. Decreasing moderate snow becoming light. Moderate E winds at the Pass becoming light by afternoon.
Friday Night Very cold. Cloudy with light snow developing in the early morning hours
Saturday Very cold. Decreasing light snow.
Friday Night Cold. Increasing light snow.
Saturday Cold. Light to moderate snow becoming light by afternoon.
Friday Night Cold. Light to moderate snow.
Saturday Cold. Light to moderate snow decreasing.
Friday Night Cold. Heavy snow.
Saturday Cold. Heavy snow decreasing into the moderate range during the afternoon.

Issued: 2:10 PM PST Friday, February 12, 2021

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

Issued: 2:10 PM PST Friday, February 12, 2021

Snow Level (ft)

Friday Evening* Friday Night* Saturday Morning* Saturday Afternoon* Saturday Evening* Saturday Night* Sunday Morning* Sunday Afternoon*
Olympics 0 0 0 0 0 0 0 1500'
West North 0 0 0 0 0 0 0 0
West Central 0 0 0 0 0 0 0 0
West South 0 0 0 0 0 0 0 500'
Stevens Pass 0 0 0 0 0 0 0 0
Snoqualmie Pass 0 0 0 0 0 0 0 0
East North 0 0 0 0 0 0 0 0
East Central 0 0 0 0 0 0 0 0
East South 0 0 0 0 0 0 0 0
Mt. Hood 0 0 0 0 0 0 0 500'
Olympics Elevation
Friday Evening* 0'
Friday Night* 0'
Saturday Morning* 0'
Saturday Afternoon* 0'
Saturday Evening* 0'
Saturday Night* 0'
Sunday Morning* 0'
Sunday Afternoon* 1500'
West North Elevation
Friday Evening* 0'
Friday Night* 0'
Saturday Morning* 0'
Saturday Afternoon* 0'
Saturday Evening* 0'
Saturday Night* 0'
Sunday Morning* 0'
Sunday Afternoon* 0'
West Central Elevation
Friday Evening* 0'
Friday Night* 0'
Saturday Morning* 0'
Saturday Afternoon* 0'
Saturday Evening* 0'
Saturday Night* 0'
Sunday Morning* 0'
Sunday Afternoon* 0'
West South Elevation
Friday Evening* 0'
Friday Night* 0'
Saturday Morning* 0'
Saturday Afternoon* 0'
Saturday Evening* 0'
Saturday Night* 0'
Sunday Morning* 0'
Sunday Afternoon* 500'
Stevens Pass Elevation
Friday Evening* 0'
Friday Night* 0'
Saturday Morning* 0'
Saturday Afternoon* 0'
Saturday Evening* 0'
Saturday Night* 0'
Sunday Morning* 0'
Sunday Afternoon* 0'
Snoqualmie Pass Elevation
Friday Evening* 0'
Friday Night* 0'
Saturday Morning* 0'
Saturday Afternoon* 0'
Saturday Evening* 0'
Saturday Night* 0'
Sunday Morning* 0'
Sunday Afternoon* 0'
East North Elevation
Friday Evening* 0'
Friday Night* 0'
Saturday Morning* 0'
Saturday Afternoon* 0'
Saturday Evening* 0'
Saturday Night* 0'
Sunday Morning* 0'
Sunday Afternoon* 0'
East Central Elevation
Friday Evening* 0'
Friday Night* 0'
Saturday Morning* 0'
Saturday Afternoon* 0'
Saturday Evening* 0'
Saturday Night* 0'
Sunday Morning* 0'
Sunday Afternoon* 0'
East South Elevation
Friday Evening* 0'
Friday Night* 0'
Saturday Morning* 0'
Saturday Afternoon* 0'
Saturday Evening* 0'
Saturday Night* 0'
Sunday Morning* 0'
Sunday Afternoon* 0'
Mt. Hood Elevation
Friday Evening* 0'
Friday Night* 0'
Saturday Morning* 0'
Saturday Afternoon* 0'
Saturday Evening* 0'
Saturday Night* 0'
Sunday Morning* 0'
Sunday Afternoon* 500'

Issued: 2:10 PM PST Friday, February 12, 2021

5000' Temperatures (°F)

Friday Night Saturday
Max / Min Max / Min
Olympics 24 / 20 22 / 18
West North 14 / 11 18 / 14
West Central 9 / 7 15 / 8
West South 15 / 13 19 / 13
Stevens Pass 5 / 4 12 / 5
Snoqualmie Pass 6 / 4 13 / 6
East North 4 / 0 12 / 2
East Central 5 / 2 11 / 3
East South 5 / 2 11 / 2
Mt. Hood 12 / 8 22 / 6
Olympics 5000' Temperature Forecast
(Max / Min)
Friday Night 24 / 20
Saturday 22 / 18
West North 5000' Temperature Forecast
(Max / Min)
Friday Night 14 / 11
Saturday 18 / 14
West Central 5000' Temperature Forecast
(Max / Min)
Friday Night 9 / 7
Saturday 15 / 8
West South 5000' Temperature Forecast
(Max / Min)
Friday Night 15 / 13
Saturday 19 / 13
Stevens Pass 5000' Temperature Forecast
(Max / Min)
Friday Night 5 / 4
Saturday 12 / 5
Snoqualmie Pass 5000' Temperature Forecast
(Max / Min)
Friday Night 6 / 4
Saturday 13 / 6
East North 5000' Temperature Forecast
(Max / Min)
Friday Night 4 / 0
Saturday 12 / 2
East Central 5000' Temperature Forecast
(Max / Min)
Friday Night 5 / 2
Saturday 11 / 3
East South 5000' Temperature Forecast
(Max / Min)
Friday Night 5 / 2
Saturday 11 / 2
Mt. Hood 5000' Temperature Forecast
(Max / Min)
Friday Night 12 / 8
Saturday 22 / 6

Issued: 2:10 PM PST Friday, February 12, 2021

Ridgeline Winds (mph)

Friday Evening Friday Night Saturday Morning Saturday Afternoon
Olympics SSE 5-15 SSE 5-15 SSE 0-10 WSW 0-10
West North ESE 5-15 ESE 5-15 ESE 5-15 SE 0-10
West Central ESE 15-25 ESE 20-30 ESE 15-25 ESE 10-20
West South ESE 5-15 ESE 15-25 SE 10-20 SSE 0-10
Stevens Pass ESE 15-25 ESE 20-30 ESE 15-25 E 10-20
Snoqualmie Pass ESE 15-25 ESE 20-30 ESE 15-25 ESE 10-20
East North ESE 10-20 ESE 10-20 ESE 10-20 ESE 10-20
East Central ESE 10-20 ESE 10-20 ESE 10-20 E 0-10
East South E 5-15 E 5-15 ESE 5-15 SE 0-10
Mt. Hood WSW 15-25 SW 15-25 WSW 20-30 W 20-30
Olympics Ridgeline Winds (mph)
Friday Evening SSE 5-15
Friday Night SSE 5-15
Saturday Morning SSE 0-10
Saturday Afternoon WSW 0-10
West North Ridgeline Winds (mph)
Friday Evening ESE 5-15
Friday Night ESE 5-15
Saturday Morning ESE 5-15
Saturday Afternoon SE 0-10
West Central Ridgeline Winds (mph)
Friday Evening ESE 15-25
Friday Night ESE 20-30
Saturday Morning ESE 15-25
Saturday Afternoon ESE 10-20
West South Ridgeline Winds (mph)
Friday Evening ESE 5-15
Friday Night ESE 15-25
Saturday Morning SE 10-20
Saturday Afternoon SSE 0-10
Stevens Pass Ridgeline Winds (mph)
Friday Evening ESE 15-25
Friday Night ESE 20-30
Saturday Morning ESE 15-25
Saturday Afternoon E 10-20
Snoqualmie Pass Ridgeline Winds (mph)
Friday Evening ESE 15-25
Friday Night ESE 20-30
Saturday Morning ESE 15-25
Saturday Afternoon ESE 10-20
East North Ridgeline Winds (mph)
Friday Evening ESE 10-20
Friday Night ESE 10-20
Saturday Morning ESE 10-20
Saturday Afternoon ESE 10-20
East Central Ridgeline Winds (mph)
Friday Evening ESE 10-20
Friday Night ESE 10-20
Saturday Morning ESE 10-20
Saturday Afternoon E 0-10
East South Ridgeline Winds (mph)
Friday Evening E 5-15
Friday Night E 5-15
Saturday Morning ESE 5-15
Saturday Afternoon SE 0-10
Mt. Hood Ridgeline Winds (mph)
Friday Evening WSW 15-25
Friday Night SW 15-25
Saturday Morning WSW 20-30
Saturday Afternoon W 20-30

Issued: 2:10 PM PST Friday, February 12, 2021

Extended Weather Synopsis

The anomalously cold upper low parked over south-central Canada for nearly a week begins to migrate eastward and weaken. This allows a shift away from the modified arctic airmass toward more typical temperatures as we head into early next week. A series of short-wave systems on W and then NW flow should maintain the snowy pattern. With snow levels only rising slightly above sea level and very cold air firmly in place across the Northwest, these storms should continue to produce some very low-density snow in the mountains.

Extended Snow Level (ft)

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

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

Previous forecast from Feb 12, 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’.