Issued: 7:02 AM PST Wednesday, December 23, 2020
by Dennis D'Amico

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

Weather Synopsis

High pressure will dominate our weather for the next 2+ days.  High freezing levels and above freezing temperatures will dominate to the west of the Cascade crest with much cooler air to the east side of the Cascades. The Cascade Passes and to a lesser extent, Mt Hood will battle between mild and cool air masses.  Snoqualmie and White Passes should see milder air and above freezing temperatures at their upper elevation sensors while Stevens will likely stay in the freezer through this period. 

As always with cool easterly offshore flow and a strong ridge of high-pressure moving overhead, there is a decent amount of uncertainty and large regional variation from East to West across the forecast area. Other than a few high clouds this morning and the potential for low clouds in the Passes/valleys on the east slopes of the Cascades later tonight and tomorrow, mostly clear skies are expected over the short term. 

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
Wednesday Mostly sunny. Periods of high clouds in the morning.
Wednesday Night Mostly clear.
Wednesday Mostly sunny. Periods of high clouds in the morning.
Wednesday Night Mostly clear.
Wednesday Mostly sunny. Periods of high clouds in the morning.
Wednesday Night Mostly clear.
Wednesday Mostly sunny. Periods of high clouds in the morning. Cooler near the Cascade crest including White Pass.
Wednesday Night Mostly clear. Cooler near the Cascade crest including White Pass. Areas of low clouds possible White Pass.
Wednesday Mostly sunny. Periods of high clouds in the morning.
Wednesday Night Mostly clear. Areas of low clouds possible overnight. Light east winds at Pass level.
Wednesday Mostly sunny. Periods of high clouds in the morning.
Wednesday Night Mostly clear. Areas of low clouds possible overnight. Light to moderate east winds at Pass level.
Wednesday Mostly sunny. Periods of high clouds in the morning.
Wednesday Night Mostly clear. Areas of low clouds possible valleys and lower slopes overnight.
Wednesday Mostly sunny. Periods of high clouds in the morning.
Wednesday Night Mostly clear. Areas of low clouds possible valleys and lower slopes overnight.
Wednesday Mostly sunny. Periods of high clouds in the morning.
Wednesday Night Mostly clear. Areas of low clouds possible valleys and lower slopes overnight.
Wednesday Mostly sunny.
Wednesday Night Mostly clear.

Precipitation (in)

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

Snow Level (ft)

Wednesday Morning* Wednesday Afternoon* Wednesday Evening* Wednesday Night* Thursday Morning* Thursday Afternoon*
Olympics 5500' 8000' 9000' 9000' 8000' 7000'
West North 3000' 6000' 7000' 7000' 7000' 6500'
West Central 3500' 7000' 8000' 8000' 8000' 6500'
West South 4500' 7500' 9000' 9000' 8500' 7500'
Stevens Pass 3000' 4000' 4000' 4000' 4000' 4000'
Snoqualmie Pass 3000' 5500' 6500' 7500' 8000' 7000'
East North 1500' 3000' 3000' 3000' 3000' 3000'
East Central 1500' 3000' 3000' 3000' 3000' 3000'
East South 2500' 5000' 5000' 6000' 7000' 6000'
Mt. Hood 4500' 9000' 10000' 10000' 10000' 9000'
Olympics Elevation
Wednesday Morning* 5500'
Wednesday Afternoon* 8000'
Wednesday Evening* 9000'
Wednesday Night* 9000'
Thursday Morning* 8000'
Thursday Afternoon* 7000'
West North Elevation
Wednesday Morning* 3000'
Wednesday Afternoon* 6000'
Wednesday Evening* 7000'
Wednesday Night* 7000'
Thursday Morning* 7000'
Thursday Afternoon* 6500'
West Central Elevation
Wednesday Morning* 3500'
Wednesday Afternoon* 7000'
Wednesday Evening* 8000'
Wednesday Night* 8000'
Thursday Morning* 8000'
Thursday Afternoon* 6500'
West South Elevation
Wednesday Morning* 4500'
Wednesday Afternoon* 7500'
Wednesday Evening* 9000'
Wednesday Night* 9000'
Thursday Morning* 8500'
Thursday Afternoon* 7500'
Stevens Pass Elevation
Wednesday Morning* 3000'
Wednesday Afternoon* 4000'
Wednesday Evening* 4000'
Wednesday Night* 4000'
Thursday Morning* 4000'
Thursday Afternoon* 4000'
Snoqualmie Pass Elevation
Wednesday Morning* 3000'
Wednesday Afternoon* 5500'
Wednesday Evening* 6500'
Wednesday Night* 7500'
Thursday Morning* 8000'
Thursday Afternoon* 7000'
East North Elevation
Wednesday Morning* 1500'
Wednesday Afternoon* 3000'
Wednesday Evening* 3000'
Wednesday Night* 3000'
Thursday Morning* 3000'
Thursday Afternoon* 3000'
East Central Elevation
Wednesday Morning* 1500'
Wednesday Afternoon* 3000'
Wednesday Evening* 3000'
Wednesday Night* 3000'
Thursday Morning* 3000'
Thursday Afternoon* 3000'
East South Elevation
Wednesday Morning* 2500'
Wednesday Afternoon* 5000'
Wednesday Evening* 5000'
Wednesday Night* 6000'
Thursday Morning* 7000'
Thursday Afternoon* 6000'
Mt. Hood Elevation
Wednesday Morning* 4500'
Wednesday Afternoon* 9000'
Wednesday Evening* 10000'
Wednesday Night* 10000'
Thursday Morning* 10000'
Thursday Afternoon* 9000'

5000' Temperatures (°F)

Wednesday Wednesday Night
Max / Min Max / Min
Olympics 38 / 28 37 / 34
West North 33 / 22 34 / 30
West Central 35 / 24 35 / 30
West South 39 / 24 36 / 33
Stevens Pass 32 / 21 26 / 23
Snoqualmie Pass 31 / 20 32 / 26
East North 30 / 20 22 / 20
East Central 31 / 20 25 / 24
East South 33 / 18 29 / 25
Mt. Hood 36 / 22 33 / 29
Olympics 5000' Temperature Forecast
(Max / Min)
Wednesday 38 / 28
Wednesday Night 37 / 34
West North 5000' Temperature Forecast
(Max / Min)
Wednesday 33 / 22
Wednesday Night 34 / 30
West Central 5000' Temperature Forecast
(Max / Min)
Wednesday 35 / 24
Wednesday Night 35 / 30
West South 5000' Temperature Forecast
(Max / Min)
Wednesday 39 / 24
Wednesday Night 36 / 33
Stevens Pass 5000' Temperature Forecast
(Max / Min)
Wednesday 32 / 21
Wednesday Night 26 / 23
Snoqualmie Pass 5000' Temperature Forecast
(Max / Min)
Wednesday 31 / 20
Wednesday Night 32 / 26
East North 5000' Temperature Forecast
(Max / Min)
Wednesday 30 / 20
Wednesday Night 22 / 20
East Central 5000' Temperature Forecast
(Max / Min)
Wednesday 31 / 20
Wednesday Night 25 / 24
East South 5000' Temperature Forecast
(Max / Min)
Wednesday 33 / 18
Wednesday Night 29 / 25
Mt. Hood 5000' Temperature Forecast
(Max / Min)
Wednesday 36 / 22
Wednesday Night 33 / 29

Ridgeline Winds (mph)

Wednesday Morning Wednesday Afternoon Wednesday Evening Wednesday Night
Olympics VAR 0-10 SSW 0-10 SSW 5-15 SSW 5-15
West North VAR 0-10 SSW 0-10 SSW 5-15 SSW 10-20
West Central VAR 0-10 SSE 0-10 S 5-15 S 10-20
West South S 5-15 SSE 5-15 SSE 10-20 S 10-20
Stevens Pass SE 0-10 SE 5-15 SSE 5-15 SE 5-15
Snoqualmie Pass SE 5-15 SE 10-20 SE 10-20 SE 10-20
East North SSW 10-20 SSW 5-15 SSW 5-15 SW 5-15
East Central S 5-15 SSE 5-15 SSE 10-20 S 5-15
East South S 5-15 S 5-15 S 5-15 S 5-15
Mt. Hood SSE 5-15 SSE 10-20 SSE 10-20 S 10-20
Olympics Ridgeline Winds (mph)
Wednesday Morning VAR 0-10
Wednesday Afternoon SSW 0-10
Wednesday Evening SSW 5-15
Wednesday Night SSW 5-15
West North Ridgeline Winds (mph)
Wednesday Morning VAR 0-10
Wednesday Afternoon SSW 0-10
Wednesday Evening SSW 5-15
Wednesday Night SSW 10-20
West Central Ridgeline Winds (mph)
Wednesday Morning VAR 0-10
Wednesday Afternoon SSE 0-10
Wednesday Evening S 5-15
Wednesday Night S 10-20
West South Ridgeline Winds (mph)
Wednesday Morning S 5-15
Wednesday Afternoon SSE 5-15
Wednesday Evening SSE 10-20
Wednesday Night S 10-20
Stevens Pass Ridgeline Winds (mph)
Wednesday Morning SE 0-10
Wednesday Afternoon SE 5-15
Wednesday Evening SSE 5-15
Wednesday Night SE 5-15
Snoqualmie Pass Ridgeline Winds (mph)
Wednesday Morning SE 5-15
Wednesday Afternoon SE 10-20
Wednesday Evening SE 10-20
Wednesday Night SE 10-20
East North Ridgeline Winds (mph)
Wednesday Morning SSW 10-20
Wednesday Afternoon SSW 5-15
Wednesday Evening SSW 5-15
Wednesday Night SW 5-15
East Central Ridgeline Winds (mph)
Wednesday Morning S 5-15
Wednesday Afternoon SSE 5-15
Wednesday Evening SSE 10-20
Wednesday Night S 5-15
East South Ridgeline Winds (mph)
Wednesday Morning S 5-15
Wednesday Afternoon S 5-15
Wednesday Evening S 5-15
Wednesday Night S 5-15
Mt. Hood Ridgeline Winds (mph)
Wednesday Morning SSE 5-15
Wednesday Afternoon SSE 10-20
Wednesday Evening SSE 10-20
Wednesday Night S 10-20

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

Previous forecast from Dec 22, 2020

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’.