Issued: 7:21 AM PST Thursday, January 11, 2018
by Dennis D'Amico

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

Weather Synopsis for Thursday & Friday

A developing low pressure system off the coast of central Vancouver Island will spread warm frontal precipitation over the region today with an occluded front passing through the Cascades mid-afternoon.  Precipitation and winds will be heaviest/strongest from the central Washington Cascades and south to Mt. Hood. Less wind, precipitation and warming is expected for the Olympics and Mt. Baker area as the low pressure system weakens and takes a due westward track today. 

Snow levels will peak for the west slopes of the Cascades and Mt. Hood but excluding the Passes late morning through mid-day. Snow levels in the Paradise/Crystal area should peak in the 5000-5500 ft range through early afternoon. The Passes will hold onto cool easterly flow until the frontal passage this afternoon, with Snoqualmie Pass seeing a change to rain by late afternoon and Stevens Pass likely seeing rain to 4500 feet in the evening. 

Post frontal shower activity will begin to wane during the day on Friday and westerlies will come down a notch as upper level ridging quickly builds in our near shore waters. Despite the ridge axis moving over the Cascades Friday night, warm frontal precipitation from a low pressure in the Gulf of Alaska will slip some light rain and snow mainly for the Olympics and north/central Cascades into the area. 

Weather Forecast

Olympics
Thursday Moderate rain and snow. Slow warming trend.
Thursday Night Light to occasionally moderate rain and snow showers decreasing after midnight. Breezy overnight.
Friday Light rain and snow showers tapering in the afternoon but remaining cloudy.
Washington Cascades near and west of the Crest including Stevens, Snoqualmie and White Passes
Thursday Stormy conditions developing with moderate to occasionally heavy rain and snow except light to moderate Mt. Baker area with less wind. Rain mixing in at Snoqualmie Pass late afternoon. Slow warming trend.
Thursday Night Moderate rain and snow showers, heaviest central and south Washington Cascades decreasing after midnight. Rain mixing in at Stevens Pass likely overnight. Windy.
Friday Light to occasionally moderate rain and snow showers tapering in the afternoon but remaining cloudy.
East Slopes of the Washington Cascades
Thursday Stormy conditions developing with moderate rain and snow near the crest and strong alpine winds. Slow warming trend.
Thursday Night Moderate rain and snow showers, heaviest near the crest decreasing after midnight. Rain mixing in at lower elevations along the east slopes overnight. Windy.
Friday Light rain and snow showers tapering in the afternoon but remaining cloudy.
Mt. Hood
Thursday Stormy conditions developing with moderate to occasionally heavy rain and snow. Warming trend peaking late morning through mid-day with slight cooling by late afternoon.
Thursday Night Moderate rain and snow showers decreasing after midnight. Very windy.
Friday Light rain and snow showers tapering in the afternoon and becoming mostly cloudy in the afternoon. Winds decreasing during the day.

Snow/Freezing Level (ft)

Hurricane Ridge Mt. Baker Washington Pass Leavenworth Stevens Pass Snoqualmie Pass Mt. Rainier, Crystal & White Pass Mt. Hood
Thursday Morning Snow Level * 3500' 2000' 1500' ' ' 3000' ' 5500'
Thursday Afternoon Snow Level * 4500' 3000' 3000' ' ' 4500' ' 5500'
Thursday Night Snow Level 5000' 3500' 3500' ' ' 5000' ' 5500'
Friday Morning Snow Level 5000' 4500' 4500' ' ' 4500' ' 5000'
Friday Afternoon Snow Level 4000' 4000' 4000' ' ' 4000' ' 4500'
Friday Night Snow Level 6000' 4500' 4000' ' ' 5000' ' 6500'
Hurricane Ridge Elevation
Thursday Morning Snow Level
3500'
(Easterly Flow *)
Thursday Afternoon Snow Level
4500'
(Easterly Flow *)
Thursday Night Snow Level
5000'
Friday Morning Snow Level
5000'
Friday Afternoon Snow Level
4000'
Friday Night Snow Level
6000'
Thursday Mid-day Snow Level
4000'
(Easterly Flow *)
Mt. Baker Elevation
Thursday Morning Snow Level
2000'
(Easterly Flow *)
Thursday Afternoon Snow Level
3000'
(Easterly Flow *)
Thursday Night Snow Level
3500'
Friday Morning Snow Level
4500'
Friday Afternoon Snow Level
4000'
Friday Night Snow Level
4500'
Thursday Mid-day Snow Level
2500'
(Easterly Flow *)
Washington Pass Elevation
Thursday Morning Snow Level
1500'
(Easterly Flow *)
Thursday Afternoon Snow Level
3000'
(Easterly Flow *)
Thursday Night Snow Level
3500'
Friday Morning Snow Level
4500'
Friday Afternoon Snow Level
4000'
Friday Night Snow Level
4000'
Thursday Mid-day Snow Level
2000'
(Easterly Flow *)
Leavenworth Elevation
Thursday Morning Snow Level
'
(Easterly Flow *)
Thursday Afternoon Snow Level
'
(Easterly Flow *)
Thursday Night Snow Level
'
Friday Morning Snow Level
'
Friday Afternoon Snow Level
'
Friday Night Snow Level
'
Thursday Mid-day Snow Level
'
(Easterly Flow *)
Stevens Pass Elevation
Thursday Morning Snow Level
'
(Easterly Flow *)
Thursday Afternoon Snow Level
'
(Easterly Flow *)
Thursday Night Snow Level
'
Friday Morning Snow Level
'
Friday Afternoon Snow Level
'
Friday Night Snow Level
'
Thursday Mid-day Snow Level
'
(Easterly Flow *)
Snoqualmie Pass Elevation
Thursday Morning Snow Level
3000'
(Easterly Flow *)
Thursday Afternoon Snow Level
4500'
(Easterly Flow *)
Thursday Night Snow Level
5000'
Friday Morning Snow Level
4500'
Friday Afternoon Snow Level
4000'
Friday Night Snow Level
5000'
Thursday Mid-day Snow Level
3000'
(Easterly Flow *)
Mt. Rainier & Crystal Elevation
Thursday Morning Snow Level
'
(Easterly Flow *)
Thursday Afternoon Snow Level
'
(Easterly Flow *)
Thursday Night Snow Level
'
Friday Morning Snow Level
'
Friday Afternoon Snow Level
'
Friday Night Snow Level
'
Thursday Mid-day Snow Level
'
(Easterly Flow *)
Mt. Hood Elevation
Thursday Morning Snow Level
5500'
(Easterly Flow *)
Thursday Afternoon Snow Level
5500'
(Easterly Flow *)
Thursday Night Snow Level
5500'
Friday Morning Snow Level
5000'
Friday Afternoon Snow Level
4500'
Friday Night Snow Level
6500'
Thursday Mid-day Snow Level
6500'
(Easterly Flow *)

* 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

Friday Friday
Hurricane Ridge 1.00 - 1.50 LT 0.25
Mt Baker Ski Area 1.00 - 1.50 0.25 - 0.50
Washington Pass 1.00 - 1.50 LT 0.25
Stevens Pass 1.50 - 2.50 0.50 - 0.75
Snoqualmie Pass 2.00 - 3.00 0 - 0.75
Mission Ridge 1.00 - 1.50 LT 0.10
Crystal Mt 1.50 - 2.00 LT 0.25
Paradise 3.00 - 4.00 0 - 0.50
White Pass 0 - 2.00 LT 0.25
Mt Hood Meadows 1.50 - 2.50 0.25 - 0.50
2.00 - 3.00 0.25 - 0.50

Free Winds at 5000' (mph)

Hurricane Ridge Mt. Baker Stevens to Snoqualmie Pass Mt. Rainier Mt. Hood
Thursday Morning SE 5 - 15 E 5 - 15 ESE 15 - 25 --- - SW 20 - 30
Thursday Afternoon SW 15 - 25 E 5 - 15 SW 25 - 35 --- - SW 45 - 55
Thursday Night S 5 - 15 S 5 - 15 SW 25 - 35 --- - SW 45 - 55
Friday Morning SW 10 - 20 SW 5 - 15 WSW 15 - 30 --- - WSW 25 - 35
Friday Afternoon SW 5 - 15 SW 5 - 15 WSW 10 - 20 --- - SW 10 - 20
Hurricane Ridge Elevation
Thursday Morning SE 5 - 15
Thursday Afternoon SW 15 - 25
Thursday Night S 5 - 15
Friday Morning SW 10 - 20
Friday Afternoon SW 5 - 15
Friday Night SW 15 - 25
Mt. Baker Elevation
Thursday Morning E 5 - 15
Thursday Afternoon E 5 - 15
Thursday Night S 5 - 15
Friday Morning SW 5 - 15
Friday Afternoon SW 5 - 15
Friday Night S 10 - 20
Stevens and Snoqualmie Pass Elevation
Thursday Morning ESE 15 - 25
Thursday Afternoon SW 25 - 35
Thursday Night SW 25 - 35
Friday Morning WSW 15 - 30
Friday Afternoon WSW 10 - 20
Friday Night SW 5 - 15
Mt. Rainier Elevation
Thursday Morning --- -
Thursday Afternoon --- -
Thursday Night --- -
Friday Morning --- -
Friday Afternoon --- -
Friday Night --- -
Mt. Hood Elevation
Thursday Morning SW 20 - 30
Thursday Afternoon SW 45 - 55
Thursday Night SW 45 - 55
Friday Morning WSW 25 - 35
Friday Afternoon SW 10 - 20
Friday Night SW 5 - 15
Hurricane Ridge Direction - Speed
Thursday Morning SE 5 - 15
Thursday Afternoon SW 15 - 25
Thursday Night S 5 - 15
Friday Morning SW 10 - 20
Friday Afternoon SW 5 - 15
Friday Night SW 15 - 25
Mt. Baker Direction - Speed
Thursday Morning E 5 - 15
Thursday Afternoon E 5 - 15
Thursday Night S 5 - 15
Friday Morning SW 5 - 15
Friday Afternoon SW 5 - 15
Friday Night S 10 - 20
Stevens and Snoqualmie Pass Direction - Speed
Thursday Morning ESE 15 - 25
Thursday Afternoon SW 25 - 35
Thursday Night SW 25 - 35
Friday Morning WSW 15 - 30
Friday Afternoon WSW 10 - 20
Friday Night SW 5 - 15
Mt. Rainier Direction - Speed
Thursday Morning --- -
Thursday Afternoon --- -
Thursday Night --- -
Friday Morning --- -
Friday Afternoon --- -
Friday Night --- -
Mt. Hood Direction - Speed
Thursday Morning SW 20 - 30
Thursday Afternoon SW 45 - 55
Thursday Night SW 45 - 55
Friday Morning WSW 25 - 35
Friday Afternoon SW 10 - 20
Friday Night SW 5 - 15

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 15 - 25 SW 15 - 30 SW 25 - 35 --- - SW 40 - 50
Thursday Afternoon SW 15 - 25 SW 25 - 35 SW 45 - 60 --- - SW 65 - 75
Thursday Night SW 15 - 25 WSW 25 - 35 WSW 35 - 45 --- - SW 45 - 60
Friday Morning SW 15 - 25 WSW 20 - 30 WSW 30 - 40 --- - W 35 - 45
Friday Afternoon SW 15 - 25 W 20 - 30 W 25 - 35 --- - W 30 - 40
Mt. Baker Direction - Speed
Thursday Morning SW 15 - 25
Thursday Afternoon SW 15 - 25
Thursday Night SW 15 - 25
Friday Morning SW 15 - 25
Friday Afternoon SW 15 - 25
Friday Night W 30 - 40
Washington Pass Direction - Speed
Thursday Morning SW 15 - 30
Thursday Afternoon SW 25 - 35
Thursday Night WSW 25 - 35
Friday Morning WSW 20 - 30
Friday Afternoon W 20 - 30
Friday Night W 30 - 40
Stevens and Snoqualmie Pass Direction - Speed
Thursday Morning SW 25 - 35
Thursday Afternoon SW 45 - 60
Thursday Night WSW 35 - 45
Friday Morning WSW 30 - 40
Friday Afternoon W 25 - 35
Friday Night W 35 - 45
Mt. Rainier Direction - Speed
Thursday Morning --- -
Thursday Afternoon --- -
Thursday Night --- -
Friday Morning --- -
Friday Afternoon --- -
Friday Night --- -
Mt. Hood Direction - Speed
Thursday Morning SW 40 - 50
Thursday Afternoon SW 65 - 75
Thursday Night SW 45 - 60
Friday Morning W 35 - 45
Friday Afternoon W 30 - 40
Friday Night W 30 - 40

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.

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

Previous forecast from Jan 10, 2018

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