Issued: 2:02 PM PST Tuesday, November 17, 2020
by Robert Hahn

Jump to: Weather Forecast I Snow/Freezing Level I Precipitation I Free Winds 5k I Free Winds 9k I Extended Weather

Weather Synopsis for Tuesday night through Thursday

A very deep low will continue lifting northward off the British Columbia Coastline into the Gulf of Alaska. The associated cold front moved east of the Cascades on Tuesday afternoon, allowing progressive cooling of the atmosphere on moderate to strong SW flow ahead of the offshore upper trough. Precipitation will be heaviest during Tuesday evening, with SW-NE oriented banded shower activity weakening after midnight ahead of a moderately organized circulation center also arriving on SW flow and poised to bring more sustained rain and snow during the day on Wednesday. Wednesday's disturbance should renew moderate to occasionally heavy rain and snow from SW to NE across the region on Wednesday morning with rain and snow shower activity continuing in the afternoon. The flow pattern should favor the SW slopes of the Olympics, Mt. Baker, and Mt. Rainier Tuesday night and Wednesday. Mt. Hood should also receive significant moisture on Wednesday.

Winds should shift WSW Wednesday night with light to moderate snow shower activity focusing on the west slopes of our mountains as snow levels lower further to Snoqualmie Pass level or below as the upper trough moves into the region. The snow shower activity should become light by Thursday with the cool upper trough centered over the region.

Weather Forecast

Hurricane Ridge
Tuesday Night Light to occasional moderate rain and snow showers. Moderate winds becoming light to moderate after midnight.
Mt. Baker
Tuesday Night Heavy rain and snow showers becoming light to moderate after midnight. Moderate 5000 ft winds.
Washington Pass and Leavenworth
Tuesday Night Moderate rain and snow showers becoming light after midnight at Washington Pass. Generally light snow showers in areas further south and east of the Cascade Crest. Decreasing strong winds in the alpine.
Stevens and Snoqualmie Pass
Tuesday Night Moderate rain and snow showers becoming light or possibly ending after midnight. Moderate 5000 ft winds becoming light to moderate after midnight. Pass-level winds W 5-15, switching E 5-15 in the early morning hours.
Mt. Rainier, Crystal and White Pass
Tuesday Night Moderate to heavy snow showers at Paradise with light rain and snow showers at Crystal and White Pass. Shower activity decreasing after midnight. Moderate 5000 ft wind becoming light to moderate after midnight.
Mt. Hood
Tuesday Night Light rain and snow showers. Very strong, but decreasing winds in the alpine.

Snow/Freezing Level (ft)

Hurricane Ridge Mt. Baker Washington Pass Leavenworth Stevens Pass Snoqualmie Pass Mt. Rainier, Crystal & White Pass Mt. Hood
Tuesday Evening Snow Level 4000' 4500' 4500' 5000' 4500' 5000' 5000' 5000'
Tuesday Night Snow Level 4000' 3500' 4000' 4000' 4000' 4000' 4000' 4000'
Wednesday Morning Snow Level * 3500' 3500' 3000' 3000' 3000' 3500' 3500' 4000'
Wednesday Afternoon Snow Level * 3500' 3000' 3000' 3000' 3500' 3500' 3500' 4000'
Wednesday Evening Snow Level 3000' 3000' 3000' 3000' 3000' 3000' 3000' 3000'
Wednesday Night Snow Level 2000' 2500' 2500' 2500' 2500' 2500' 2500' 3000'
Thursday Morning Snow Level 2500' 2000' 1500' 2000' 2500' 2500' 2500' 3000'
Hurricane Ridge Elevation
Tuesday Evening Snow Level
4000'
Tuesday Night Snow Level
4000'
Wednesday Morning Snow Level
3500'
(Easterly Flow *)
Wednesday Afternoon Snow Level
3500'
(Easterly Flow *)
Wednesday Evening Snow Level
3000'
Wednesday Night Snow Level
2000'
Thursday Morning Snow Level
2500'
Thursday Afternoon Snow Level
2500'
Mt. Baker Elevation
Tuesday Evening Snow Level
4500'
Tuesday Night Snow Level
3500'
Wednesday Morning Snow Level
3500'
(Easterly Flow *)
Wednesday Afternoon Snow Level
3000'
(Easterly Flow *)
Wednesday Evening Snow Level
3000'
Wednesday Night Snow Level
2500'
Thursday Morning Snow Level
2000'
Thursday Afternoon Snow Level
2000'
Washington Pass Elevation
Tuesday Evening Snow Level
4500'
Tuesday Night Snow Level
4000'
Wednesday Morning Snow Level
3000'
(Easterly Flow *)
Wednesday Afternoon Snow Level
3000'
(Easterly Flow *)
Wednesday Evening Snow Level
3000'
Wednesday Night Snow Level
2500'
Thursday Morning Snow Level
1500'
Thursday Afternoon Snow Level
2000'
Leavenworth Elevation
Tuesday Evening Snow Level
5000'
Tuesday Night Snow Level
4000'
Wednesday Morning Snow Level
3000'
(Easterly Flow *)
Wednesday Afternoon Snow Level
3000'
(Easterly Flow *)
Wednesday Evening Snow Level
3000'
Wednesday Night Snow Level
2500'
Thursday Morning Snow Level
2000'
Thursday Afternoon Snow Level
3000'
Stevens Pass Elevation
Tuesday Evening Snow Level
4500'
Tuesday Night Snow Level
4000'
Wednesday Morning Snow Level
3000'
(Easterly Flow *)
Wednesday Afternoon Snow Level
3500'
(Easterly Flow *)
Wednesday Evening Snow Level
3000'
Wednesday Night Snow Level
2500'
Thursday Morning Snow Level
2500'
Thursday Afternoon Snow Level
2500'
Snoqualmie Pass Elevation
Tuesday Evening Snow Level
5000'
Tuesday Night Snow Level
4000'
Wednesday Morning Snow Level
3500'
(Easterly Flow *)
Wednesday Afternoon Snow Level
3500'
(Easterly Flow *)
Wednesday Evening Snow Level
3000'
Wednesday Night Snow Level
2500'
Thursday Morning Snow Level
2500'
Thursday Afternoon Snow Level
2500'
Mt. Rainier & Crystal Elevation
Tuesday Evening Snow Level
5000'
Tuesday Night Snow Level
4000'
Wednesday Morning Snow Level
3500'
(Easterly Flow *)
Wednesday Afternoon Snow Level
3500'
(Easterly Flow *)
Wednesday Evening Snow Level
3000'
Wednesday Night Snow Level
2500'
Thursday Morning Snow Level
2500'
Thursday Afternoon Snow Level
2500'
Mt. Hood Elevation
Tuesday Evening Snow Level
5000'
Tuesday Night Snow Level
4000'
Wednesday Morning Snow Level
4000'
(Easterly Flow *)
Wednesday Afternoon Snow Level
4000'
(Easterly Flow *)
Wednesday Evening Snow Level
3000'
Wednesday Night Snow Level
3000'
Thursday Morning Snow Level
3000'
Thursday Afternoon Snow Level
3000'

* Easterly flow in the Cascade Passes can cause locally lower Snow or Freezing levels than areas further west.
Freezing Level is when no precipitation is forecast.

Precipitation Forecast

Tuesday Night Wednesday Wednesday Night Thursday
4 pm - 4 am 4 am - 4 pm 4 pm - 4 am 4 am - 4 pm
Hurricane Ridge 0.25 0.25 - 0.50 LT 0.10 LT 0.10
Mt Baker Ski Area 1.00 0.75 0.50 - 0.75 0.25
Washington Pass 0.25 - 0.50 0.25 0.25 LT 0.10
Leavenworth LT 0.10 0.25 LT 0.10 0
Stevens Pass 0.25 - 0.50 0.25 0.25 LT 0.25
Snoqualmie Pass 0.50 0.25 - 0.50 0.25 0.25
Mission Ridge LT 0.10 0.25 LT 0.10 0
Crystal Mt 0.25 0.50 LT 0.25 LT 0.10
Paradise 0.75 -1.00 1.00 - 1.50 0.75 0.50
White Pass 0.25 0.50 0.25 LT 0.25
Mt Hood Meadows LT 0.25 1.00 0.75 0.25 - 0.50
0.25 1.00 0.75 -1.00 0.50
Hurricane Ridge Precipitation Forecast
Tuesday Night 0.25
Wednesday 0.25 - 0.50
Wednesday Night LT 0.10
Thursday LT 0.10
Mt Baker Ski Area Precipitation Forecast
Tuesday Night 1.00
Wednesday 0.75
Wednesday Night 0.50 - 0.75
Thursday 0.25
Washington Pass Precipitation Forecast
Tuesday Night 0.25 - 0.50
Wednesday 0.25
Wednesday Night 0.25
Thursday LT 0.10
Leavenworth Precipitation Forecast
Tuesday Night LT 0.10
Wednesday 0.25
Wednesday Night LT 0.10
Thursday 0
Stevens Pass Precipitation Forecast
Tuesday Night 0.25 - 0.50
Wednesday 0.25
Wednesday Night 0.25
Thursday LT 0.25
Snoqualmie Pass Precipitation Forecast
Tuesday Night 0.50
Wednesday 0.25 - 0.50
Wednesday Night 0.25
Thursday 0.25
Mission Ridge Precipitation Forecast
Tuesday Night LT 0.10
Wednesday 0.25
Wednesday Night LT 0.10
Thursday 0
Crystal Mt Precipitation Forecast
Tuesday Night 0.25
Wednesday 0.50
Wednesday Night LT 0.25
Thursday LT 0.10
Paradise Precipitation Forecast
Tuesday Night 0.75 -1.00
Wednesday 1.00 - 1.50
Wednesday Night 0.75
Thursday 0.50
White Pass Precipitation Forecast
Tuesday Night 0.25
Wednesday 0.50
Wednesday Night 0.25
Thursday LT 0.25
Mt Hood Meadows Precipitation Forecast
Tuesday Night LT 0.25
Wednesday 1.00
Wednesday Night 0.75
Thursday 0.25 - 0.50
Timberline Precipitation Forecast
Tuesday Night 0.25
Wednesday 1.00
Wednesday Night 0.75 -1.00
Thursday 0.50

Free Winds at 5000' (mph)

Hurricane Ridge Mt. Baker Stevens to Snoqualmie Pass Mt. Rainier Mt. Hood
Tuesday Evening SW 15 - 25 S 20 - 30 SSW 20 - 30 SSW 20 - 30 SW 20 - 30
Tuesday Night SSW 10 - 20 S 15 - 25 S 10 - 20 SSW 10 - 20 SSW 15 - 25
Wednesday Morning S 10 - 20 ESE 10 - 20 SSE 10 - 20 SSE 10 - 20 SW 15 - 25
Hurricane Ridge Elevation
Tuesday Evening SW 15 - 25
Tuesday Night SSW 10 - 20
Wednesday Morning S 10 - 20
Wednesday Afternoon SW 15 - 25
Mt. Baker Elevation
Tuesday Evening S 20 - 30
Tuesday Night S 15 - 25
Wednesday Morning ESE 10 - 20
Wednesday Afternoon S 20 - 30
Stevens and Snoqualmie Pass Elevation
Tuesday Evening SSW 20 - 30
Tuesday Night S 10 - 20
Wednesday Morning SSE 10 - 20
Wednesday Afternoon SW 20 - 30
Mt. Rainier Elevation
Tuesday Evening SSW 20 - 30
Tuesday Night SSW 10 - 20
Wednesday Morning SSE 10 - 20
Wednesday Afternoon SW 20 - 30
Mt. Hood Elevation
Tuesday Evening SW 20 - 30
Tuesday Night SSW 15 - 25
Wednesday Morning SW 15 - 25
Wednesday Afternoon WSW 25 - 35
Hurricane Ridge Direction - Speed
Tuesday Evening SW 15 - 25
Tuesday Night SSW 10 - 20
Wednesday Morning S 10 - 20
Wednesday Afternoon SW 15 - 25
Mt. Baker Direction - Speed
Tuesday Evening S 20 - 30
Tuesday Night S 15 - 25
Wednesday Morning ESE 10 - 20
Wednesday Afternoon S 20 - 30
Stevens and Snoqualmie Pass Direction - Speed
Tuesday Evening SSW 20 - 30
Tuesday Night S 10 - 20
Wednesday Morning SSE 10 - 20
Wednesday Afternoon SW 20 - 30
Mt. Rainier Direction - Speed
Tuesday Evening SSW 20 - 30
Tuesday Night SSW 10 - 20
Wednesday Morning SSE 10 - 20
Wednesday Afternoon SW 20 - 30
Mt. Hood Direction - Speed
Tuesday Evening SW 20 - 30
Tuesday Night SSW 15 - 25
Wednesday Morning SW 15 - 25
Wednesday Afternoon WSW 25 - 35

Directions above indicate the direction the wind blows from on the 16-point cardinal scale. These winds indicate "free" winds, or those winds in the atmosphere not influenced by terrain. Topographical effects may produce greater or lower wind speeds in certain locations as well as significant variations in direction.

Free Winds at 9000' (mph)

Mt. Baker Washington Pass Stevens to Snoqualmie Pass Mt. Rainier Mt. Hood
Tuesday Evening SSW 30 - 40 SW 35 - 50 SW 45 - 65 SW 40 - 60 SW 50 - 70
Tuesday Night SW 25 - 35 WSW 30 - 40 SW 30 - 40 SW 30 - 40 WSW 35 - 50
Wednesday Morning S 15 - 25 SSE 20 - 30 SSW 20 - 30 SSW 25 - 35 WSW 35 - 50
Mt. Baker Direction - Speed
Tuesday Evening SSW 30 - 40
Tuesday Night SW 25 - 35
Wednesday Morning S 15 - 25
Wednesday Afternoon SSW 30 - 40
Washington Pass Direction - Speed
Tuesday Evening SW 35 - 50
Tuesday Night WSW 30 - 40
Wednesday Morning SSE 20 - 30
Wednesday Afternoon SW 20 - 30
Stevens and Snoqualmie Pass Direction - Speed
Tuesday Evening SW 45 - 65
Tuesday Night SW 30 - 40
Wednesday Morning SSW 20 - 30
Wednesday Afternoon SW 30 - 40
Mt. Rainier Direction - Speed
Tuesday Evening SW 40 - 60
Tuesday Night SW 30 - 40
Wednesday Morning SSW 25 - 35
Wednesday Afternoon SW 30 - 40
Mt. Hood Direction - Speed
Tuesday Evening SW 50 - 70
Tuesday Night WSW 35 - 50
Wednesday Morning WSW 35 - 50
Wednesday Afternoon WSW 40 - 55

Extended Weather Synopsis for Thursday night through Saturday

The trough moderates and slides eastward as a weak ridge builds in the nearshore waters. Rain and snow shower activity should remain generally light and focused on the west slopes of the Cascades Thursday night through Saturday morning with the chance for the Mt. Hood region to dry out and warm slightly as the offshore ridge nudges into the region. Saturday afternoon could see some drier conditions across the region with another storm moving into our nearshore waters.

Extended Snow/Freezing Levels

Mt. Baker Snoqualmie Pass Mt. Hood Easterly Flow *
Thursday Night Snow Level 1000' - 2000' 1500' - 2500' 2000' - 3000'
Friday Snow Level 2000' - 3000' 2500' - 3500' 2500' - 4000'
Friday Night Snow Level 2000' - 3000' 2500' - 3500' 3000' - 4000'
Mt. Baker Elevation
Thursday Night Snow Level
1000' - 2000'
Friday Snow Level
2000' - 3000'
Friday Night Snow Level
2000' - 3000'
Saturday Snow Level
2000' - 3000'
Snoqualmie Pass Elevation
Thursday Night Snow Level
1500' - 2500'
Friday Snow Level
2500' - 3500'
Friday Night Snow Level
2500' - 3500'
Saturday Snow Level
2500' - 3500'
Mt. Hood Elevation
Thursday Night Snow Level
2000' - 3000'
Friday Snow Level
2500' - 4000'
Friday Night Snow Level
3000' - 4000'
Saturday Snow Level
3500' - 5000'

* Easterly flow in the Cascade Passes can cause locally lower Snow or Freezing levels than areas further west.
Freezing Level is when no precipitation is forecast.

Jump to: Weather Forecast I Snow/Freezing Level I Precipitation I Free Winds 5k I Free Winds 9k I Extended Weather

Previous forecast from Nov 16, 2020

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