Issued: 2:18 PM PST Sunday, December 26, 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 mountains will experience dangerously cold temperatures, with the coldest temperatures likely Sunday night and Monday before temperatures very gradually start warming (but rest assured it will remain frigid).

A winter storm winds down Sunday but could bring another 5-8" low-density snow to Mt. Hood and possibly similar amounts in a few locations in the central and southern Washington Cascades. Light snow and snow showers die down overnight of night across Washington as an upper-level trough shifts east of the Cascades. Snow should linger into the early morning hours for Mt. Hood. Fraser river outflow remains strong through Sunday night, meaning that weakly modified arctic air continues to spill into the Puget Sound lowlands. Air will be cold at all levels of the atmosphere. At 5000 ft, we expect below-zero temperatures Sunday night and Monday morning, with highs in the single digits or low teens on Monday. Skies may partially clear in some areas early Monday before a weak low dropping south off the British Columbia coastline begins spreading high clouds into the region.

That low should bring a glancing shot of light snow to the Olympics, southern Washington Cascades, and Mt. Hood late Monday night into Tuesday morning. These areas could pick up to 3 inches of low-density snow. Skies should partially clear again Tuesday afternoon with temperatures warming 5-10F west of the Cascade Crest while the warming will be less apparent east of the Cascades.

 

 

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
Sunday Night Light snow possible early and ends during the evening. Partial clearing overnight.
Monday Cloudy.
Sunday Night Light snow showers possible early and ends during the evening. Then, clearing from the late evening onwards.
Monday Scattered low clouds early, then increasing mid and high-level clouds from mid-morning onward.
Sunday Night Light snow possible early and ends during the evening. Then, partial clearing overnight.
Monday Scattered low clouds early, then increasing mid and high-level clouds from mid-morning onward.
Sunday Night Decreasing light snow showers.
Monday Scattered low clouds early, then increasing mid and high-level clouds from mid-morning onward.
Sunday Night Decreasing light snow showers with partial clearing after midnight. Light E wind at the Pass.
Monday Scattered low clouds early, then increasing mid and high-level clouds from mid-morning onward. Light E wind switching W at the Pass.
Sunday Night Decreasing light snow showers with partial clearing after midnight. Light E wind at the Pass.
Monday Scattered low clouds early, then increasing mid and high-level clouds from mid-morning onward. Light E wind switching W at the Pass.
Sunday Night Light snow possible at times with partial clearing by the early morning hours.
Monday Mostly clear to start, then increasing high and mid-level clouds from late morning onwards.
Sunday Night Light snow possible at times, ending by the early morning hours.
Monday Scattered clouds to start, then increasing high and mid-level clouds from late morning onwards.
Sunday Night Periods of light snow or snow showers.
Monday Scattered clouds to start, then increasing high and mid-level clouds from late morning onwards.
Sunday Night Moderate snow becoming light overnight. Strong wind gusts in the evening hours.
Monday Partly to mostly cloudy.

Issued: 2:18 PM PST Sunday, December 26, 2021

Precipitation (in)

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

Issued: 2:18 PM PST Sunday, December 26, 2021

Snow Level (ft)

Sunday Evening* Sunday Night* Monday Morning* Monday Afternoon Monday Evening Monday Night Tuesday Morning* Tuesday Afternoon*
Olympics 0 0 0 0 0 0 0 0
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 0
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 0
Olympics Elevation
Sunday Evening* 0'
Sunday Night* 0'
Monday Morning* 0'
Monday Afternoon 0'
Monday Evening 0'
Monday Night 0'
Tuesday Morning* 0'
Tuesday Afternoon* 0'
West North Elevation
Sunday Evening* 0'
Sunday Night* 0'
Monday Morning* 0'
Monday Afternoon 0'
Monday Evening 0'
Monday Night 0'
Tuesday Morning* 0'
Tuesday Afternoon* 0'
West Central Elevation
Sunday Evening* 0'
Sunday Night* 0'
Monday Morning* 0'
Monday Afternoon 0'
Monday Evening 0'
Monday Night 0'
Tuesday Morning* 0'
Tuesday Afternoon* 0'
West South Elevation
Sunday Evening* 0'
Sunday Night* 0'
Monday Morning* 0'
Monday Afternoon 0'
Monday Evening 0'
Monday Night 0'
Tuesday Morning* 0'
Tuesday Afternoon* 0'
Stevens Pass Elevation
Sunday Evening* 0'
Sunday Night* 0'
Monday Morning* 0'
Monday Afternoon 0'
Monday Evening 0'
Monday Night 0'
Tuesday Morning* 0'
Tuesday Afternoon* 0'
Snoqualmie Pass Elevation
Sunday Evening* 0'
Sunday Night* 0'
Monday Morning* 0'
Monday Afternoon 0'
Monday Evening 0'
Monday Night 0'
Tuesday Morning* 0'
Tuesday Afternoon* 0'
East North Elevation
Sunday Evening* 0'
Sunday Night* 0'
Monday Morning* 0'
Monday Afternoon 0'
Monday Evening 0'
Monday Night 0'
Tuesday Morning* 0'
Tuesday Afternoon* 0'
East Central Elevation
Sunday Evening* 0'
Sunday Night* 0'
Monday Morning* 0'
Monday Afternoon 0'
Monday Evening 0'
Monday Night 0'
Tuesday Morning* 0'
Tuesday Afternoon* 0'
East South Elevation
Sunday Evening* 0'
Sunday Night* 0'
Monday Morning* 0'
Monday Afternoon 0'
Monday Evening 0'
Monday Night 0'
Tuesday Morning* 0'
Tuesday Afternoon* 0'
Mt. Hood Elevation
Sunday Evening* 0'
Sunday Night* 0'
Monday Morning* 0'
Monday Afternoon 0'
Monday Evening 0'
Monday Night 0'
Tuesday Morning* 0'
Tuesday Afternoon* 0'

Issued: 2:18 PM PST Sunday, December 26, 2021

5000' Temperatures (°F)

Sunday Night Monday
Max / Min Max / Min
Olympics 2 / -4 5 / -4
West North 2 / -4 3 / -7
West Central 5 / -1 4 / -3
West South 5 / -1 5 / -3
Stevens Pass 5 / -2 4 / -6
Snoqualmie Pass 5 / -1 5 / -3
East North -5 / -10 0 / -12
East Central 1 / -3 4 / -4
East South 4 / -1 5 / -4
Mt. Hood 10 / 2 9 / 0
Olympics 5000' Temperature Forecast
(Max / Min)
Sunday Night 2 / -4
Monday 5 / -4
West North 5000' Temperature Forecast
(Max / Min)
Sunday Night 2 / -4
Monday 3 / -7
West Central 5000' Temperature Forecast
(Max / Min)
Sunday Night 5 / -1
Monday 4 / -3
West South 5000' Temperature Forecast
(Max / Min)
Sunday Night 5 / -1
Monday 5 / -3
Stevens Pass 5000' Temperature Forecast
(Max / Min)
Sunday Night 5 / -2
Monday 4 / -6
Snoqualmie Pass 5000' Temperature Forecast
(Max / Min)
Sunday Night 5 / -1
Monday 5 / -3
East North 5000' Temperature Forecast
(Max / Min)
Sunday Night -5 / -10
Monday 0 / -12
East Central 5000' Temperature Forecast
(Max / Min)
Sunday Night 1 / -3
Monday 4 / -4
East South 5000' Temperature Forecast
(Max / Min)
Sunday Night 4 / -1
Monday 5 / -4
Mt. Hood 5000' Temperature Forecast
(Max / Min)
Sunday Night 10 / 2
Monday 9 / 0

Issued: 2:18 PM PST Sunday, December 26, 2021

Ridgeline Winds (mph)

Sunday Evening Sunday Night Monday Morning Monday Afternoon
Olympics NNE 0-10 NE 0-10 NW 0-10 WNW 0-10
West North ENE 5-15 NE 0-10 W 0-10 W 0-10
West Central SE 0-10 ESE 0-10 W 0-10 W 5-15
West South SW 5-15 VAR 0-10 W 0-10 W 5-15
Stevens Pass SE 5-15 E 0-10 W 0-10 W 5-15
Snoqualmie Pass SE 5-15 E 0-10 W 0-10 W 5-15
East North SE 0-10 NNW 0-10 W 0-10 W 5-15
East Central SSE 5-15 E 0-10 W 0-10 W 5-15
East South WSW 5-15 S 0-10 W 0-10 W 5-15
Mt. Hood W 15-25 W 5-15 W 5-15 W 10-20
Olympics Ridgeline Winds (mph)
Sunday Evening NNE 0-10
Sunday Night NE 0-10
Monday Morning NW 0-10
Monday Afternoon WNW 0-10
West North Ridgeline Winds (mph)
Sunday Evening ENE 5-15
Sunday Night NE 0-10
Monday Morning W 0-10
Monday Afternoon W 0-10
West Central Ridgeline Winds (mph)
Sunday Evening SE 0-10
Sunday Night ESE 0-10
Monday Morning W 0-10
Monday Afternoon W 5-15
West South Ridgeline Winds (mph)
Sunday Evening SW 5-15
Sunday Night VAR 0-10
Monday Morning W 0-10
Monday Afternoon W 5-15
Stevens Pass Ridgeline Winds (mph)
Sunday Evening SE 5-15
Sunday Night E 0-10
Monday Morning W 0-10
Monday Afternoon W 5-15
Snoqualmie Pass Ridgeline Winds (mph)
Sunday Evening SE 5-15
Sunday Night E 0-10
Monday Morning W 0-10
Monday Afternoon W 5-15
East North Ridgeline Winds (mph)
Sunday Evening SE 0-10
Sunday Night NNW 0-10
Monday Morning W 0-10
Monday Afternoon W 5-15
East Central Ridgeline Winds (mph)
Sunday Evening SSE 5-15
Sunday Night E 0-10
Monday Morning W 0-10
Monday Afternoon W 5-15
East South Ridgeline Winds (mph)
Sunday Evening WSW 5-15
Sunday Night S 0-10
Monday Morning W 0-10
Monday Afternoon W 5-15
Mt. Hood Ridgeline Winds (mph)
Sunday Evening W 15-25
Sunday Night W 5-15
Monday Morning W 5-15
Monday Afternoon W 10-20

Issued: 2:18 PM PST Sunday, December 26, 2021

Extended Weather Synopsis

NW flow keeps the region cold, but very gradually warming Tuesday night and Wednesday. Mostly clear skies Tuesday night will give way to increasing clouds on Wednesday as a stronger system drops down the west coast of Canada.This system arrives with light snow overnight becoming moderate on Thursday. Moderate to strong west winds should allow for efficient snow production. We expect 6-12" of snow or locally higher amounts with this storm. Snow levels remain near sea level.

Extended Snow Level (ft)

Tuesday Night* Wednesday * Wednesday Night Thursday
West North 0 0 0 0
Snoqualmie Pass 0 0 0 0
Mt. Hood 0 0 0 0
West North Elevation
Tuesday Night* 0'
Wednesday * 0'
Wednesday Night 0'
Thursday 0'
Snoqualmie Pass Elevation
Tuesday Night* 0'
Wednesday * 0'
Wednesday Night 0'
Thursday 0'
Mt. Hood Elevation
Tuesday Night* 0'
Wednesday * 0'
Wednesday Night 0'
Thursday 0'

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

Previous forecast from Dec 26, 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’.