Issued: 2:34 PM PST Tuesday, December 28, 2021
by Robert Hahn

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

Weather Synopsis

Temperatures remain unusually cold and very slowly moderating over the next several days as NNW flow continues to bring weak and moisture-starved systems to our region. These systems continue to produce low-density snow with minimal water content. The first system to impact our region will be a trough sliding down the east slopes of the mountains from interior British Columbia. After some very light snowfall in the northern parts of Washington Friday evening, it may tap into just enough moisture from the ocean to create some 2-6" accumulations from around Snoqualmie Pass south to Mt. Hood. With light to moderate east flow in place at low-levels, expect the east slopes of the Cascades to be slightly favored.

Expect clouds to clear from north to south across Washington State on Wednesday while some light snow lingers in the Mt. Hood area through the morning hours.

A somewhat stronger trough slides down the British Columbia coastline Wednesday evening, spreading increasing light to moderate snowfall to northwest Washington State.

That snowfall should increase on Thursday, increasingly focusing on areas from highway 20 southward. Many areas can expect 6-12" of snow Wednesday night through Thursday, with locally higher amounts possible in the central Washington Cascades. Southern parts of the forecast region can also expect moderate to strong ridgeline winds.

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
Tuesday Night Light snow.
Wednesday A few clouds early, then mostly sunny.
Tuesday Night Very light snow during the evening hours.
Wednesday Mostly sunny with high clouds increasing late in the day.
Tuesday Night Very light snow developing.
Wednesday Mostly sunny with high clouds increasing late in the day.
Tuesday Night Cloudy in the evening with light snow overnight.
Wednesday Mostly cloudy to start, then clearing skies.
Tuesday Night Periods of light snow. Increasing light to occasionally moderate E winds at the Pass.
Wednesday Partly cloudy to start, then clearing skies. Light to moderate E wind at the Pass.
Tuesday Night Light snow. Increasing light to occasionally moderate E winds at the Pass.
Wednesday Partly cloudy to start, then clearing skies. Light to moderate E wind at the Pass.
Tuesday Night Light snow ending by morning.
Wednesday Sunny with high clouds increasing late in the day.
Tuesday Night Increasing light snow.
Wednesday Partly cloudy to start the day, then becoming mostly sunny.
Tuesday Night Light snow developing and increasing overnight.
Wednesday Mostly cloudy in the morning, transitioning to mostly sunny by the afternoon.
Tuesday Night Periods of light snow.
Wednesday Light snow in the morning, then decreasing clouds. Becoming mostly sunny in the afternoon.

Issued: 2:34 PM PST Tuesday, December 28, 2021

Precipitation (in)

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

Issued: 2:34 PM PST Tuesday, December 28, 2021

Snow Level (ft)

Tuesday Evening* Tuesday Night* Wednesday Morning* Wednesday Afternoon* Wednesday Evening Wednesday Night Thursday Morning* Thursday 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 0 500'
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 0 500'
Mt. Hood 0 0 0 0 0 0 0 1000'
Olympics Elevation
Tuesday Evening* 0'
Tuesday Night* 0'
Wednesday Morning* 0'
Wednesday Afternoon* 0'
Wednesday Evening 0'
Wednesday Night 0'
Thursday Morning* 0'
Thursday Afternoon* 0'
West North Elevation
Tuesday Evening* 0'
Tuesday Night* 0'
Wednesday Morning* 0'
Wednesday Afternoon* 0'
Wednesday Evening 0'
Wednesday Night 0'
Thursday Morning* 0'
Thursday Afternoon* 0'
West Central Elevation
Tuesday Evening* 0'
Tuesday Night* 0'
Wednesday Morning* 0'
Wednesday Afternoon* 0'
Wednesday Evening 0'
Wednesday Night 0'
Thursday Morning* 0'
Thursday Afternoon* 0'
West South Elevation
Tuesday Evening* 0'
Tuesday Night* 0'
Wednesday Morning* 0'
Wednesday Afternoon* 0'
Wednesday Evening 0'
Wednesday Night 0'
Thursday Morning* 0'
Thursday Afternoon* 500'
Stevens Pass Elevation
Tuesday Evening* 0'
Tuesday Night* 0'
Wednesday Morning* 0'
Wednesday Afternoon* 0'
Wednesday Evening 0'
Wednesday Night 0'
Thursday Morning* 0'
Thursday Afternoon* 0'
Snoqualmie Pass Elevation
Tuesday Evening* 0'
Tuesday Night* 0'
Wednesday Morning* 0'
Wednesday Afternoon* 0'
Wednesday Evening 0'
Wednesday Night 0'
Thursday Morning* 0'
Thursday Afternoon* 0'
East North Elevation
Tuesday Evening* 0'
Tuesday Night* 0'
Wednesday Morning* 0'
Wednesday Afternoon* 0'
Wednesday Evening 0'
Wednesday Night 0'
Thursday Morning* 0'
Thursday Afternoon* 0'
East Central Elevation
Tuesday Evening* 0'
Tuesday Night* 0'
Wednesday Morning* 0'
Wednesday Afternoon* 0'
Wednesday Evening 0'
Wednesday Night 0'
Thursday Morning* 0'
Thursday Afternoon* 0'
East South Elevation
Tuesday Evening* 0'
Tuesday Night* 0'
Wednesday Morning* 0'
Wednesday Afternoon* 0'
Wednesday Evening 0'
Wednesday Night 0'
Thursday Morning* 0'
Thursday Afternoon* 500'
Mt. Hood Elevation
Tuesday Evening* 0'
Tuesday Night* 0'
Wednesday Morning* 0'
Wednesday Afternoon* 0'
Wednesday Evening 0'
Wednesday Night 0'
Thursday Morning* 0'
Thursday Afternoon* 1000'

Issued: 2:34 PM PST Tuesday, December 28, 2021

5000' Temperatures (°F)

Tuesday Night Wednesday
Max / Min Max / Min
Olympics 14 / 7 20 / 3
West North 15 / 6 15 / 4
West Central 16 / 8 16 / 5
West South 19 / 11 20 / 6
Stevens Pass 13 / 3 13 / 2
Snoqualmie Pass 14 / 5 14 / 4
East North 8 / -5 9 / -6
East Central 12 / 0 11 / 1
East South 15 / 3 13 / 2
Mt. Hood 20 / 12 15 / 5
Olympics 5000' Temperature Forecast
(Max / Min)
Tuesday Night 14 / 7
Wednesday 20 / 3
West North 5000' Temperature Forecast
(Max / Min)
Tuesday Night 15 / 6
Wednesday 15 / 4
West Central 5000' Temperature Forecast
(Max / Min)
Tuesday Night 16 / 8
Wednesday 16 / 5
West South 5000' Temperature Forecast
(Max / Min)
Tuesday Night 19 / 11
Wednesday 20 / 6
Stevens Pass 5000' Temperature Forecast
(Max / Min)
Tuesday Night 13 / 3
Wednesday 13 / 2
Snoqualmie Pass 5000' Temperature Forecast
(Max / Min)
Tuesday Night 14 / 5
Wednesday 14 / 4
East North 5000' Temperature Forecast
(Max / Min)
Tuesday Night 8 / -5
Wednesday 9 / -6
East Central 5000' Temperature Forecast
(Max / Min)
Tuesday Night 12 / 0
Wednesday 11 / 1
East South 5000' Temperature Forecast
(Max / Min)
Tuesday Night 15 / 3
Wednesday 13 / 2
Mt. Hood 5000' Temperature Forecast
(Max / Min)
Tuesday Night 20 / 12
Wednesday 15 / 5

Issued: 2:34 PM PST Tuesday, December 28, 2021

Ridgeline Winds (mph)

Tuesday Evening Tuesday Night Wednesday Morning Wednesday Afternoon
Olympics NNE 0-10 NNE 5-15 NNE 10-20 NNW 0-10
West North NE 0-10 NNE 10-20 NE 5-15 WNW 0-10
West Central SSW 0-10 N 0-10 NE 0-10 NW 0-10
West South SW 0-10 W 0-10 NNE 0-10 N 0-10
Stevens Pass SW 0-10 ESE 0-10 ENE 5-15 NNW 0-10
Snoqualmie Pass WSW 0-10 ESE 0-10 ENE 5-15 NNW 0-10
East North NNW 0-10 N 5-15 ENE 5-15 WNW 0-10
East Central WSW 0-10 E 0-10 ENE 5-15 N 5-15
East South WSW 0-10 SSW 0-10 NE 5-15 N 0-10
Mt. Hood SW 5-15 WSW 5-15 NE 0-10 NE 0-10
Olympics Ridgeline Winds (mph)
Tuesday Evening NNE 0-10
Tuesday Night NNE 5-15
Wednesday Morning NNE 10-20
Wednesday Afternoon NNW 0-10
West North Ridgeline Winds (mph)
Tuesday Evening NE 0-10
Tuesday Night NNE 10-20
Wednesday Morning NE 5-15
Wednesday Afternoon WNW 0-10
West Central Ridgeline Winds (mph)
Tuesday Evening SSW 0-10
Tuesday Night N 0-10
Wednesday Morning NE 0-10
Wednesday Afternoon NW 0-10
West South Ridgeline Winds (mph)
Tuesday Evening SW 0-10
Tuesday Night W 0-10
Wednesday Morning NNE 0-10
Wednesday Afternoon N 0-10
Stevens Pass Ridgeline Winds (mph)
Tuesday Evening SW 0-10
Tuesday Night ESE 0-10
Wednesday Morning ENE 5-15
Wednesday Afternoon NNW 0-10
Snoqualmie Pass Ridgeline Winds (mph)
Tuesday Evening WSW 0-10
Tuesday Night ESE 0-10
Wednesday Morning ENE 5-15
Wednesday Afternoon NNW 0-10
East North Ridgeline Winds (mph)
Tuesday Evening NNW 0-10
Tuesday Night N 5-15
Wednesday Morning ENE 5-15
Wednesday Afternoon WNW 0-10
East Central Ridgeline Winds (mph)
Tuesday Evening WSW 0-10
Tuesday Night E 0-10
Wednesday Morning ENE 5-15
Wednesday Afternoon N 5-15
East South Ridgeline Winds (mph)
Tuesday Evening WSW 0-10
Tuesday Night SSW 0-10
Wednesday Morning NE 5-15
Wednesday Afternoon N 0-10
Mt. Hood Ridgeline Winds (mph)
Tuesday Evening SW 5-15
Tuesday Night WSW 5-15
Wednesday Morning NE 0-10
Wednesday Afternoon NE 0-10

Issued: 2:34 PM PST Tuesday, December 28, 2021

Extended Weather Synopsis

Post frontal snow decreases and ends from north to south on Thursday night as the trough shifts eastward, but not before parts of the Washington Cascades pick up an additional 2-6" and Mt. Hood picks up around 5-10". Light snow should continue in the Mt. Hood area through late Friday, while other areas experience partial clearing. A ridge building offshore combined with a weak warm front brings in some milder air at upper levels, but with deeply entrenched cold air across the regions, most mountain locations will be slow to warm. Light snowfall commences early Saturday and continues throughout the day.

Extended Snow Level (ft)

Thursday Night* Friday * Friday Night* Saturday *
West North 0 0 0 0
Snoqualmie Pass 0 0 0 500'
Mt. Hood 1500' 0 0 1000'
West North Elevation
Thursday Night* 0'
Friday * 0'
Friday Night* 0'
Saturday * 0'
Snoqualmie Pass Elevation
Thursday Night* 0'
Friday * 0'
Friday Night* 0'
Saturday * 500'
Mt. Hood Elevation
Thursday Night* 1500'
Friday * 0'
Friday Night* 0'
Saturday * 1000'

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

Previous forecast from Dec 28, 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’.