Issued: 1:57 PM PST Thursday, December 30, 2021
by Dallas Glass

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

Weather Synopsis

An exiting disturbance will maintain a few leftover snow showers as we head into the evening hours, particularly for areas in the southern half of the forecast region. However, most locations shouldn't see more than another inch or so of snow. As we begin to dry out overnight, expect cold temperatures to return as dry northerly winds draw frigid air in from Canada. Many locations could experience overnight lows in the teens or single digits. Skies will continue to clear from north to south overnight, with only partial clearing of locations closer to Oregon. Stormy weather could linger at Mt Hood into the evening. While there is some uncertainty, most weather models want to keep the snowy and windy conditions going until the early morning hours. This could result in significant additional snow for the Hood area. 

By Friday morning, a high-pressure ridge shifts over the Northwest further helping the region dry out and clear up. While you may find some low-level clouds in the mountain valleys and pass in the morning, Friday looks like a beautiful day with mostly sunny skies, cold temperatures, and generally light winds. Hood may once again be the exception. Leftover moisture and NW winds could continue to ring out light snow showers throughout the day. 

The break in the weather looks short-lived. A large low-pressure system in the Gulf of Alaska will slowly begin to slide south and draw moisture up from the Pacific. While most locations should stay dry Friday night and Saturday. the approaching storm will spread clouds and stronger alpine winds across the Pacific Northwest. The bulk of the precipitation should stay focussed in southern British Columbia during the short-term forecast, however, a few showers could slop over the border to Hurricane Ridge, Mt Baker, and Washington Pass. This low-pressure system will drive our weather as we continue through the weekend and into next week. 

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 Mostly clear with some low clouds. Slight chance of a few flurries, especially along the northern part of the Olympics. Cold.
Friday Sunny. Light NNE winds.
Thursday Night Partly cloudy to mostly clear. Low-level clouds in the valleys. Cold.
Friday Mostly sunny. Light NW winds.
Thursday Night Partly cloudy to mostly clear. Low-level clouds in the valleys. Cold. Slight chance of a few flurries south of Highway 2.
Friday Becoming mostly sunny. Light winds.
Thursday Night Partly to mostly cloudy. Low-level clouds in the mountain valleys and passes. Cold. Isolated snow showers.
Friday Becoming mostly sunny. Cloudier near Mt Adams and Mt St Helens. Light winds.
Thursday Night Mostly cloudy becoming partly clear. Low-level clouds in the mountain valleys and passes. Cold. Slight chance for a few snow showers. Light westerly flow.
Friday Becoming partly to mostly sunny. Light easterly flow.
Thursday Night Mostly cloudy with some clearing. Low-level clouds in the mountain valleys and passes. Cold. Slight chance of a few snow showers. Light westerly flow.
Friday Becoming partly sunny. Light easterly flow.
Thursday Night Partly to mostly clear. Low-level clouds in the mountain valleys and passes. Cold.
Friday Becoming sunny. Light NNE winds.
Thursday Night Mostly to partly cloudy. With some clearing further east. Low-level clouds in the mountain valleys and passes. Cold. A few lingering flurries are possible
Friday Becoming mostly sunny. Light winds.
Thursday Night Mostly cloudy. Cold. A few snow showers are possible, particularly further south. Light to moderate NW winds.
Friday Becoming mostly sunny with increasing clouds further south. Light winds.
Thursday Night Stormy. Occasionally moderate snow. Strong WNW winds decreasing slightly overnight.
Friday Cloudy with occasional sun breaks in the afternoon. Scattered showers. Moderate NW winds decreasing in the afternoon.

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

Snow Level (ft)

Thursday Evening Thursday Night Friday Morning Friday Afternoon* Friday Evening* Friday Night* Saturday Morning* Saturday Afternoon*
Olympics 0 0 0 0 0 0 0 1000'
West North 0 0 0 0 0 0 0 0
West Central 0 0 0 0 0 0 0 500'
West South 0 0 0 500' 0 0 0 1000'
Stevens Pass 0 0 0 0 0 0 0 1000'
Snoqualmie Pass 0 0 0 0 0 0 0 1000'
East North 0 0 0 0 0 0 0 0
East Central 0 0 0 0 0 0 0 500'
East South 0 0 0 0 0 0 0 100'
Mt. Hood 1000' 500' 500' 500' 0 0 500' 1500'
Olympics Elevation
Thursday Evening 0'
Thursday Night 0'
Friday Morning 0'
Friday Afternoon* 0'
Friday Evening* 0'
Friday Night* 0'
Saturday Morning* 0'
Saturday Afternoon* 1000'
West North Elevation
Thursday Evening 0'
Thursday Night 0'
Friday Morning 0'
Friday Afternoon* 0'
Friday Evening* 0'
Friday Night* 0'
Saturday Morning* 0'
Saturday Afternoon* 0'
West Central Elevation
Thursday Evening 0'
Thursday Night 0'
Friday Morning 0'
Friday Afternoon* 0'
Friday Evening* 0'
Friday Night* 0'
Saturday Morning* 0'
Saturday Afternoon* 500'
West South Elevation
Thursday Evening 0'
Thursday Night 0'
Friday Morning 0'
Friday Afternoon* 500'
Friday Evening* 0'
Friday Night* 0'
Saturday Morning* 0'
Saturday Afternoon* 1000'
Stevens Pass Elevation
Thursday Evening 0'
Thursday Night 0'
Friday Morning 0'
Friday Afternoon* 0'
Friday Evening* 0'
Friday Night* 0'
Saturday Morning* 0'
Saturday Afternoon* 1000'
Snoqualmie Pass Elevation
Thursday Evening 0'
Thursday Night 0'
Friday Morning 0'
Friday Afternoon* 0'
Friday Evening* 0'
Friday Night* 0'
Saturday Morning* 0'
Saturday Afternoon* 1000'
East North Elevation
Thursday Evening 0'
Thursday Night 0'
Friday Morning 0'
Friday Afternoon* 0'
Friday Evening* 0'
Friday Night* 0'
Saturday Morning* 0'
Saturday Afternoon* 0'
East Central Elevation
Thursday Evening 0'
Thursday Night 0'
Friday Morning 0'
Friday Afternoon* 0'
Friday Evening* 0'
Friday Night* 0'
Saturday Morning* 0'
Saturday Afternoon* 500'
East South Elevation
Thursday Evening 0'
Thursday Night 0'
Friday Morning 0'
Friday Afternoon* 0'
Friday Evening* 0'
Friday Night* 0'
Saturday Morning* 0'
Saturday Afternoon* 100'
Mt. Hood Elevation
Thursday Evening 1000'
Thursday Night 500'
Friday Morning 500'
Friday Afternoon* 500'
Friday Evening* 0'
Friday Night* 0'
Saturday Morning* 500'
Saturday Afternoon* 1500'

5000' Temperatures (°F)

Thursday Night Friday
Max / Min Max / Min
Olympics 20 / 15 25 / 18
West North 17 / 9 13 / 9
West Central 20 / 11 18 / 12
West South 19 / 12 15 / 11
Stevens Pass 18 / 13 16 / 11
Snoqualmie Pass 20 / 13 17 / 13
East North 10 / 2 8 / -1
East Central 10 / 5 12 / 6
East South 21 / 12 18 / 13
Mt. Hood 24 / 19 25 / 17
Olympics 5000' Temperature Forecast
(Max / Min)
Thursday Night 20 / 15
Friday 25 / 18
West North 5000' Temperature Forecast
(Max / Min)
Thursday Night 17 / 9
Friday 13 / 9
West Central 5000' Temperature Forecast
(Max / Min)
Thursday Night 20 / 11
Friday 18 / 12
West South 5000' Temperature Forecast
(Max / Min)
Thursday Night 19 / 12
Friday 15 / 11
Stevens Pass 5000' Temperature Forecast
(Max / Min)
Thursday Night 18 / 13
Friday 16 / 11
Snoqualmie Pass 5000' Temperature Forecast
(Max / Min)
Thursday Night 20 / 13
Friday 17 / 13
East North 5000' Temperature Forecast
(Max / Min)
Thursday Night 10 / 2
Friday 8 / -1
East Central 5000' Temperature Forecast
(Max / Min)
Thursday Night 10 / 5
Friday 12 / 6
East South 5000' Temperature Forecast
(Max / Min)
Thursday Night 21 / 12
Friday 18 / 13
Mt. Hood 5000' Temperature Forecast
(Max / Min)
Thursday Night 24 / 19
Friday 25 / 17

Ridgeline Winds (mph)

Thursday Evening Thursday Night Friday Morning Friday Afternoon
Olympics NNW 5-15 NNW 5-15 NNE 5-15 NNE 5-15
West North NE 0-10 NE 5-15 NE 5-15 NE 0-10
West Central W 0-10 WNW 5-15 NNE 5-15 VAR 0-10
West South W 5-15 WNW 5-15 N 0-10 VAR 0-10
Stevens Pass W 0-10 WNW 5-15 ENE 0-10 VAR 0-10
Snoqualmie Pass W 5-15 WNW 10-20 ENE 0-10 VAR 0-10
East North NNW 0-10 NNE 10-20 NNE 10-20 NNE 0-10
East Central NW 5-15 NW 5-15 VAR 0-10 NW 5-15
East South WNW 10-20 NW 10-20 N 5-15 NW 0-10
Mt. Hood WNW 30-40 WNW 25-35 NW 10-20 NW 5-15
Olympics Ridgeline Winds (mph)
Thursday Evening NNW 5-15
Thursday Night NNW 5-15
Friday Morning NNE 5-15
Friday Afternoon NNE 5-15
West North Ridgeline Winds (mph)
Thursday Evening NE 0-10
Thursday Night NE 5-15
Friday Morning NE 5-15
Friday Afternoon NE 0-10
West Central Ridgeline Winds (mph)
Thursday Evening W 0-10
Thursday Night WNW 5-15
Friday Morning NNE 5-15
Friday Afternoon VAR 0-10
West South Ridgeline Winds (mph)
Thursday Evening W 5-15
Thursday Night WNW 5-15
Friday Morning N 0-10
Friday Afternoon VAR 0-10
Stevens Pass Ridgeline Winds (mph)
Thursday Evening W 0-10
Thursday Night WNW 5-15
Friday Morning ENE 0-10
Friday Afternoon VAR 0-10
Snoqualmie Pass Ridgeline Winds (mph)
Thursday Evening W 5-15
Thursday Night WNW 10-20
Friday Morning ENE 0-10
Friday Afternoon VAR 0-10
East North Ridgeline Winds (mph)
Thursday Evening NNW 0-10
Thursday Night NNE 10-20
Friday Morning NNE 10-20
Friday Afternoon NNE 0-10
East Central Ridgeline Winds (mph)
Thursday Evening NW 5-15
Thursday Night NW 5-15
Friday Morning VAR 0-10
Friday Afternoon NW 5-15
East South Ridgeline Winds (mph)
Thursday Evening WNW 10-20
Thursday Night NW 10-20
Friday Morning N 5-15
Friday Afternoon NW 0-10
Mt. Hood Ridgeline Winds (mph)
Thursday Evening WNW 30-40
Thursday Night WNW 25-35
Friday Morning NW 10-20
Friday Afternoon NW 5-15

Extended Weather Synopsis

A low-pressure system meandering its way south off the coast continues to approach the region Saturday night and Sunday. The closer it gets the greater chance we have to see showers impact the northern portions of the Cascades and Olympics. Weather models disagree about the timing of this low. We could see more significant precipitation spread into the mountains Sunday afternoon or it may hold off until overnight. Either way, eventually, stormy weather returns. This system will be slightly warmer than recent weather, however, at this point, snow levels appear to stay below the mountain passes. As the storm heads south towards California, additional small disturbances should maintain an active weather pattern with precipitation in the mountains Monday. 

Extended Snow Level (ft)

Saturday Night* Sunday * Sunday Night* Monday *
West North 1000' 2500' 1000' 500'
Snoqualmie Pass 1000' 2000' 1000' 1000'
Mt. Hood 2500' 3500' 3000' 2500'
West North Elevation
Saturday Night* 1000'
Sunday * 2500'
Sunday Night* 1000'
Monday * 500'
Snoqualmie Pass Elevation
Saturday Night* 1000'
Sunday * 2000'
Sunday Night* 1000'
Monday * 1000'
Mt. Hood Elevation
Saturday Night* 2500'
Sunday * 3500'
Sunday Night* 3000'
Monday * 2500'

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

Previous forecast from Dec 30, 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’.