Issued: 7:09 AM PST Wednesday, January 13, 2021
by Robert Hahn

Jump to: Weather Forecast I Snow Level I Precipitation I Ridgeline Winds I

Weather Synopsis

Our atmospheric river event moved east of the region as the third wave in the sequence formed a low that moved into British Columbia and a strong front pushed east of our region Tuesday night, leaving post-frontal showers, strong cooling, and decreasing moderate to strong west winds. Expect gernally decreasing post-frontal snow showers primarily from the Mountain Loop south to Mt. Hood. There is some more focused convergence in the Stevens Pass vicinity early Wednesday morning. Convergence should continue to focus on the area from Stevens Pass to the mountain loop as overall snow shower activity maintains primarily in this region during the afternoon and early evening hours before ending. Temperatures dropped 5-15F within several hours behind the front and most locations above 3500 ft are below freezing. Temperatures should continue to fall with snow levels quickly dropping below Snoqualmie Pass level.  Areas east of the Cascade Crest and in the southern parts of the Cascades should expect some partial sunshine today.

A ridge of high pressure begins to build back into the region Wednesday night leaving us with partly cloudy skies Wednesday night. Light E flow should start to develop through the mountain gaps overnight.

Thursday, the ridge amplifies over the region. Temperatures increase significantly west of the Cascade Crest while moderate E flow through the mountain gaps keeps significantly cooler temperatures that may barely get above freezing Thursday afternoon at locations such as Snoqualmie Pass. Meanwhile freezing levels should be 10,000-12,000 ft in locations such as the Olympics and Mt. Hood.

Weather Forecast

Use dropdown to select your zone
Wednesday Partly cloudy with a chance of snow showers in the morning, then more sun than clouds in the afternoon.
Wednesday Night Partly cloudy in the evening, then increasing clouds.

Precipitation (in)

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

Snow Level (ft)

Wednesday Morning Wednesday Afternoon Wednesday Evening Wednesday Night * Thursday Morning * Thursday Afternoon *
Olympics 2000' 2500' 2500' 3000' 5000' 10500'
West North 2000' 2000' 1500' 2000' 2000' 6500'
West Central 2500' 2000' 2000' 1500' 3000' 7000'
West South 2500' 2500' 1500' 2000' 4500' 10000'
Stevens Pass 2500' 2000' 2000' 1500' 2500' 4000'
Snoqualmie Pass 2500' 2000' 2000' 2000' 3000' 7500'
East North 2500' 2000' 10000' 1000' 1500' 3500'
East Central 2500' 2000' 2000' 2000' 2500' 4000'
East South 3000' 2500' 2000' 2500' 4000' 8500'
Mt. Hood 3500' 3000' 3000' 5500' 9000' 12000'
Olympics Elevation
Wednesday Morning 2000'
Wednesday Afternoon 2500'
Wednesday Evening 2500'
Wednesday Night * 3000'
Thursday Morning * 5000'
Thursday Afternoon * 10500'
West North Elevation
Wednesday Morning 2000'
Wednesday Afternoon 2000'
Wednesday Evening 1500'
Wednesday Night * 2000'
Thursday Morning * 2000'
Thursday Afternoon * 6500'
West Central Elevation
Wednesday Morning 2500'
Wednesday Afternoon 2000'
Wednesday Evening 2000'
Wednesday Night * 1500'
Thursday Morning * 3000'
Thursday Afternoon * 7000'
West South Elevation
Wednesday Morning 2500'
Wednesday Afternoon 2500'
Wednesday Evening 1500'
Wednesday Night * 2000'
Thursday Morning * 4500'
Thursday Afternoon * 10000'
Stevens Pass Elevation
Wednesday Morning 2500'
Wednesday Afternoon 2000'
Wednesday Evening 2000'
Wednesday Night * 1500'
Thursday Morning * 2500'
Thursday Afternoon * 4000'
Snoqualmie Pass Elevation
Wednesday Morning 2500'
Wednesday Afternoon 2000'
Wednesday Evening 2000'
Wednesday Night * 2000'
Thursday Morning * 3000'
Thursday Afternoon * 7500'
East North Elevation
Wednesday Morning 2500'
Wednesday Afternoon 2000'
Wednesday Evening 10000'
Wednesday Night * 1000'
Thursday Morning * 1500'
Thursday Afternoon * 3500'
East Central Elevation
Wednesday Morning 2500'
Wednesday Afternoon 2000'
Wednesday Evening 2000'
Wednesday Night * 2000'
Thursday Morning * 2500'
Thursday Afternoon * 4000'
East South Elevation
Wednesday Morning 3000'
Wednesday Afternoon 2500'
Wednesday Evening 2000'
Wednesday Night * 2500'
Thursday Morning * 4000'
Thursday Afternoon * 8500'
Mt. Hood Elevation
Wednesday Morning 3500'
Wednesday Afternoon 3000'
Wednesday Evening 3000'
Wednesday Night * 5500'
Thursday Morning * 9000'
Thursday Afternoon * 12000'

5000' Temperatures (°F)

Wednesday Wednesday Night
Max / Min Max / Min
Olympics 24 / 20 32 / 24
West North 24 / 22 28 / 23
West Central 25 / 23 30 / 24
West South 25 / 23 32 / 24
Stevens Pass 25 / 23 30 / 24
Snoqualmie Pass 25 / 23 31 / 24
East North 25 / 20 21 / 16
East Central 26 / 24 29 / 25
East South 26 / 24 31 / 26
Mt. Hood 30 / 24 37 / 30
Olympics 5000' Temperature Forecast
(Max / Min)
Wednesday 4am - 4pm 24 / 20
Wednesday 4pm - 4am 32 / 24
West North 5000' Temperature Forecast
(Max / Min)
Wednesday 4am - 4pm 24 / 22
Wednesday 4pm - 4am 28 / 23
West Central 5000' Temperature Forecast
(Max / Min)
Wednesday 4am - 4pm 25 / 23
Wednesday 4pm - 4am 30 / 24
West South 5000' Temperature Forecast
(Max / Min)
Wednesday 4am - 4pm 25 / 23
Wednesday 4pm - 4am 32 / 24
Stevens Pass 5000' Temperature Forecast
(Max / Min)
Wednesday 4am - 4pm 25 / 23
Wednesday 4pm - 4am 30 / 24
Snoqualmie Pass 5000' Temperature Forecast
(Max / Min)
Wednesday 4am - 4pm 25 / 23
Wednesday 4pm - 4am 31 / 24
East North 5000' Temperature Forecast
(Max / Min)
Wednesday 4am - 4pm 25 / 20
Wednesday 4pm - 4am 21 / 16
East Central 5000' Temperature Forecast
(Max / Min)
Wednesday 4am - 4pm 26 / 24
Wednesday 4pm - 4am 29 / 25
East South 5000' Temperature Forecast
(Max / Min)
Wednesday 4am - 4pm 26 / 24
Wednesday 4pm - 4am 31 / 26
Mt. Hood 5000' Temperature Forecast
(Max / Min)
Wednesday 4am - 4pm 30 / 24
Wednesday 4pm - 4am 37 / 30

Ridgeline Winds (mph)

Wednesday Morning Wednesday Afternoon Wednesday Evening Wednesday Night
Olympics W 15-25 WSW 10-20 VAR 0-10 SSE 0-10
West North W 15-25 W 10-20 WSW 0-10 VAR 0-10
West Central W 15-25 W 10-20 NW 0-10 NW 0-10
West South W 20-30 WSW 10-20 VAR 0-10 WSW 0-10
Stevens Pass W 25-35 W 20-30 W 5-15 W 0-10
Snoqualmie Pass W 25-35 W 20-30 W 15-25 W 0-10
East North W 20-30 WNW 15-25 W 5-15 NW 0-10
East Central W 30-40 WNW 30-40 W 5-15 W 0-10
East South W 30-40 W 25-35 W 5-15 WSW 0-10
Mt. Hood W 15-25 W 10-20 WSW 5-15 WSW 5-15
Olympics Ridgeline Winds (mph)
Wednesday Morning W 15-25
Wednesday Afternoon WSW 10-20
Wednesday Evening VAR 0-10
Wednesday Night SSE 0-10
West North Ridgeline Winds (mph)
Wednesday Morning W 15-25
Wednesday Afternoon W 10-20
Wednesday Evening WSW 0-10
Wednesday Night VAR 0-10
West Central Ridgeline Winds (mph)
Wednesday Morning W 15-25
Wednesday Afternoon W 10-20
Wednesday Evening NW 0-10
Wednesday Night NW 0-10
West South Ridgeline Winds (mph)
Wednesday Morning W 20-30
Wednesday Afternoon WSW 10-20
Wednesday Evening VAR 0-10
Wednesday Night WSW 0-10
Stevens Pass Ridgeline Winds (mph)
Wednesday Morning W 25-35
Wednesday Afternoon W 20-30
Wednesday Evening W 5-15
Wednesday Night W 0-10
Snoqualmie Pass Ridgeline Winds (mph)
Wednesday Morning W 25-35
Wednesday Afternoon W 20-30
Wednesday Evening W 15-25
Wednesday Night W 0-10
East North Ridgeline Winds (mph)
Wednesday Morning W 20-30
Wednesday Afternoon WNW 15-25
Wednesday Evening W 5-15
Wednesday Night NW 0-10
East Central Ridgeline Winds (mph)
Wednesday Morning W 30-40
Wednesday Afternoon WNW 30-40
Wednesday Evening W 5-15
Wednesday Night W 0-10
East South Ridgeline Winds (mph)
Wednesday Morning W 30-40
Wednesday Afternoon W 25-35
Wednesday Evening W 5-15
Wednesday Night WSW 0-10
Mt. Hood Ridgeline Winds (mph)
Wednesday Morning W 15-25
Wednesday Afternoon W 10-20
Wednesday Evening WSW 5-15
Wednesday Night WSW 5-15

Jump to: Weather Forecast I Snow Level I Precipitation I Ridgeline Winds I

Previous forecast from Jan 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’.