Issued: 4:27 PM PST Thursday, November 16, 2017
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 Thursday & Thursday

A cold upper trough is moving across the Pacific Northwest today, bringing instability as cold air aloft moves over the region. The strongest flow is over Northern California and Nevada and within our region, the slightly stronger flow is contributing to greater precipitation production over the Central and South Cascades parts of the forecast area. On Friday, a shortwave ridge rides over us, but slightly increasing westerly flow and lingering moisture contribute to showers in windward areas.

Weather Forecast

Olympics
Thursday

Light showers.

Thursday Night

Light showers.

Friday

Light showers.

Washington Cascades West Slopes
Thursday

Light showers north; Light to moderate showers south.

Thursday Night

Light to moderate showers.

Friday

Light showers.

Washington Cascades East Slopes
Thursday

Light showers.

Thursday Night

Light showers, heaviest high-elevation.

Friday

Light showers higher elevations.

Mt. Hood
Thursday

Increasing moderate showers.

Thursday Night

Moderate to heavy showers.

Friday

Slightly decreasing light to moderate showers.

Snow/Freezing Level (ft)

Hurricane Ridge Mt. Baker Washington Pass Leavenworth Stevens Pass Snoqualmie Pass Mt. Rainier, Crystal & White Pass Mt. Hood
Thursday Snow Level 3500' 3000' 3000' ' ' 3500' ' 4000'
Thursday Night Snow Level 2500' 2000' 2000' ' ' 2000' ' 2500'
Hurricane Ridge Elevation
Thursday Snow Level
3500'
Thursday Night Snow Level
2500'
Friday Snow Level
3000'
Mt. Baker Elevation
Thursday Snow Level
3000'
Thursday Night Snow Level
2000'
Friday Snow Level
2500'
Washington Pass Elevation
Thursday Snow Level
3000'
Thursday Night Snow Level
2000'
Friday Snow Level
2500'
Leavenworth Elevation
Thursday Snow Level
'
Thursday Night Snow Level
'
Friday Snow Level
'
Stevens Pass Elevation
Thursday Snow Level
'
Thursday Night Snow Level
'
Friday Snow Level
'
Snoqualmie Pass Elevation
Thursday Snow Level
3500'
Thursday Night Snow Level
2000'
Friday Snow Level
3000'
Mt. Rainier & Crystal Elevation
Thursday Snow Level
'
Thursday Night Snow Level
'
Friday Snow Level
'
Mt. Hood Elevation
Thursday Snow Level
4000'
Thursday Night Snow Level
2500'
Friday Snow Level
3500'

* 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

Thursday Thursday
Hurricane Ridge LT 0.10 LT 0.10
Mt Baker Ski Area 0 - 0.75 LT 0.25
Washington Pass 0.25 - 0.50 LT 0.25
Stevens Pass 0 - 0.50 0.25 - 0.50
Snoqualmie Pass 0.50 - 0.75 0 - 0.50
Mission Ridge LT 0.25 0 - 0.50
Crystal Mt LT 0.25 LT 0.25
Paradise 0 - 1.50 0 - 0.75
White Pass 0.25 - 0.50 LT 0.25
Mt Hood Meadows 1.00 - 1.50 0 - 0.50
0 - 1.00 0 - 0.50

Free Winds at 5000' (mph)

Hurricane Ridge Mt. Baker Stevens to Snoqualmie Pass Mt. Rainier Mt. Hood
Thursday - Morning SW 10 - 15 SW 10 - 15 SW 15 - 25 --- - SW 20 - 30
Thursday - Afternoon SSW 10 - 15 SSW 10 - 15 SSW 10 - 15 --- - SW 15 - 25
Thursday - Evening WSW 10 - 15 SSW 5 - 10 SW 10 - 15 --- - SW 20 - 30
Thursday - Night W 15 - 25 SW 10 - 15 WSW 20 - 30 --- - WSW 20 - 30
Friday - Morning WSW 15 - 25 WSW 15 - 25 WSW 20 - 30 --- - WSW 25 - 40
Friday - Afternoon WSW 15 - 25 WSW 15 - 25 WSW 20 - 35 --- - WSW 25 - 40
Hurricane Ridge Elevation
Thursday - Morning SW 10 - 15
Thursday - Afternoon SSW 10 - 15
Thursday - Evening WSW 10 - 15
Thursday - Night W 15 - 25
Friday - Morning WSW 15 - 25
Friday - Afternoon WSW 15 - 25
Friday - Evening SW 10 - 15
Mt. Baker Elevation
Thursday - Morning SW 10 - 15
Thursday - Afternoon SSW 10 - 15
Thursday - Evening SSW 5 - 10
Thursday - Night SW 10 - 15
Friday - Morning WSW 15 - 25
Friday - Afternoon WSW 15 - 25
Friday - Evening SW 10 - 15
Stevens and Snoqualmie Pass Elevation
Thursday - Morning SW 15 - 25
Thursday - Afternoon SSW 10 - 15
Thursday - Evening SW 10 - 15
Thursday - Night WSW 20 - 30
Friday - Morning WSW 20 - 30
Friday - Afternoon WSW 20 - 35
Friday - Evening SW 20 - 30
Mt. Rainier Elevation
Thursday - Morning --- -
Thursday - Afternoon --- -
Thursday - Evening --- -
Thursday - Night --- -
Friday - Morning --- -
Friday - Afternoon --- -
Friday - Evening --- -
Mt. Hood Elevation
Thursday - Morning SW 20 - 30
Thursday - Afternoon SW 15 - 25
Thursday - Evening SW 20 - 30
Thursday - Night WSW 20 - 30
Friday - Morning WSW 25 - 40
Friday - Afternoon WSW 25 - 40
Friday - Evening SW 20 - 30
Hurricane Ridge Direction - Speed
Thursday - Morning SW 10 - 15
Thursday - Afternoon SSW 10 - 15
Thursday - Evening WSW 10 - 15
Thursday - Night W 15 - 25
Friday - Morning WSW 15 - 25
Friday - Afternoon WSW 15 - 25
Friday - Evening SW 10 - 15
Mt. Baker Direction - Speed
Thursday - Morning SW 10 - 15
Thursday - Afternoon SSW 10 - 15
Thursday - Evening SSW 5 - 10
Thursday - Night SW 10 - 15
Friday - Morning WSW 15 - 25
Friday - Afternoon WSW 15 - 25
Friday - Evening SW 10 - 15
Stevens and Snoqualmie Pass Direction - Speed
Thursday - Morning SW 15 - 25
Thursday - Afternoon SSW 10 - 15
Thursday - Evening SW 10 - 15
Thursday - Night WSW 20 - 30
Friday - Morning WSW 20 - 30
Friday - Afternoon WSW 20 - 35
Friday - Evening SW 20 - 30
Mt. Rainier Direction - Speed
Thursday - Morning --- -
Thursday - Afternoon --- -
Thursday - Evening --- -
Thursday - Night --- -
Friday - Morning --- -
Friday - Afternoon --- -
Friday - Evening --- -
Mt. Hood Direction - Speed
Thursday - Morning SW 20 - 30
Thursday - Afternoon SW 15 - 25
Thursday - Evening SW 20 - 30
Thursday - Night WSW 20 - 30
Friday - Morning WSW 25 - 40
Friday - Afternoon WSW 25 - 40
Friday - Evening SW 20 - 30

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
Thursday Morning SW 20 - 35 SW 25 - 35 SW 25 - 35 --- - SW 30 - 45
Thursday Afternoon WSW 15 - 25 SW 20 - 30 SW 25 - 35 --- - SW 25 - 35
Thursday Evening SW 15 - 25 SW 20 - 30 WSW 25 - 35 --- - WSW 30 - 45
Thursday Night WSW 20 - 30 WSW 25 - 35 WSW 30 - 45 --- - W 35 - 50
Friday Morning W 25 - 35 WSW 30 - 45 W 40 - 55 --- - WSW 40 - 55
Friday Afternoon W 20 - 30 WSW 25 - 35 WSW 35 - 50 --- - WSW 40 - 55
Mt. Baker Direction - Speed
Thursday Morning SW 20 - 35
Thursday Afternoon WSW 15 - 25
Thursday Evening SW 15 - 25
Thursday Night WSW 20 - 30
Friday Morning W 25 - 35
Friday Afternoon W 20 - 30
Friday Night WSW 30 - 40
Washington Pass Direction - Speed
Thursday Morning SW 25 - 35
Thursday Afternoon SW 20 - 30
Thursday Evening SW 20 - 30
Thursday Night WSW 25 - 35
Friday Morning WSW 30 - 45
Friday Afternoon WSW 25 - 35
Friday Night WSW 30 - 40
Stevens and Snoqualmie Pass Direction - Speed
Thursday Morning SW 25 - 35
Thursday Afternoon SW 25 - 35
Thursday Evening WSW 25 - 35
Thursday Night WSW 30 - 45
Friday Morning W 40 - 55
Friday Afternoon WSW 35 - 50
Friday Night W 40 - 55
Mt. Rainier Direction - Speed
Thursday Morning --- -
Thursday Afternoon --- -
Thursday Evening --- -
Thursday Night --- -
Friday Morning --- -
Friday Afternoon --- -
Friday Night --- -
Mt. Hood Direction - Speed
Thursday Morning SW 30 - 45
Thursday Afternoon SW 25 - 35
Thursday Evening WSW 30 - 45
Thursday Night W 35 - 50
Friday Morning WSW 40 - 55
Friday Afternoon WSW 40 - 55
Friday Night WSW 25 - 35

Extended Weather Synopsis for Thursday night through Thursday

A front approaches on Saturday, but remains offshore, bringing increasing southwesterly flow out ahead of it. Sunday features strong southwest flow ahead as the front crosses the Pacific Northwest. It won't linger significantly, but will bring heavy precipitation. On Monday, the upper level trough exits to the east and an upper level ridge pushes into our region from the west.

Extended Weather

All Zones
Saturday

Increasing clouds, especially Olympics and Northwest Cascades.

Sunday

Increasing moderate to heavy rain and snow, first reaching Olympics and northwest Cascades zones.

Monday

Showers ending, initially Olympics and NW Cascades.

Extended Snow/Freezing Levels

Mt. Baker Snoqualmie Pass Mt. Hood Easterly Flow *
Saturday Morning - Sunday Afternoon Snow Level 2500' - 4000' 2500' - 4000' 3500' - 4500'
Sunday Evening - Monday Morning Snow Level 2000' - 3000' 2500' - 4500' 4000' - 6000'
Mt. Baker Elevation
Saturday Morning - Sunday Afternoon Snow Level
2500' - 4000'
Sunday Evening - Monday Morning Snow Level
2000' - 3000'
Monday Afternoon Snow Level
3000' - 5000'
Snoqualmie Pass Elevation
Saturday Morning - Sunday Afternoon Snow Level
2500' - 4000'
Sunday Evening - Monday Morning Snow Level
2500' - 4500'
Monday Afternoon Snow Level
4000' - 6000'
Mt. Hood Elevation
Saturday Morning - Sunday Afternoon Snow Level
3500' - 4500'
Sunday Evening - Monday Morning Snow Level
4000' - 6000'
Monday Afternoon Snow Level
6000' - 8000'

* 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 15, 2017

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