Issued: 7:29 AM PST Monday, January 29, 2018
by Robert Hahn

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

Weather Synopsis for Monday & Tuesday

The Pacific Northwest sits at the eastern edge of a band of thick clouds and generally heavy precipitation currently extending from central Vancouver Island to the Olympics and Northwest Cascades. The jetstream is dropping south around an upper low in the eastern gulf of Alaska and picking up subtropical moisture east of Hawaii. Snow levels are elevated Monday morning: Approximately 7000 ft in the Olympics and 6000 ft along the west slopes of the Cascades. 

During the day Monday, the cold frontal rainband will sag slowly southeast across Washington State. The approaching front will bring moderate to heavy rain and high elevation snow along with increasing moderate to strong crest-level SSW winds The strongest winds will likely be along the west slopes of the Cascades in the south and central parts, particularly from 2-4 PM.

By Monday afternoon the cold front will begin to move more quickly on its SE trajectory, limiting the duration of the heavy precipitation over the central and south Cascades and Hood regions relative to the Olympics and north Cascades.

Washington Pass should see all snow at pass level, while Stevens and Snoqualmie passes will see all rain as the front approaches.

The front will pass the Olympics and NW Cascades around 2PM and the rest of the Cascade crest around 4PM.  The frontal passage will be associated with rapid cooling and a switch to W-SW winds. The Olympics will cool first with a 4000 foot changeover to snow by around 4 PM, followed by the west slopes of the Cascades by around 7PM, and lastly the east slopes of the Cascades and Mt. Hood between 7 and 10 PM.

On Monday night through Tuesday night a shallow trough over our region will bring light to moderate mountain-enhanced snow showers on a moderately moist W-SW flow. Some convergence will be associated with moderate to heavy snow generally north of Stevens Pass at various times.

 

Weather Forecast

Olympics
Monday Moderate rain and high elevation snow. Moderate to strong ridgetop winds. Snow line lowing sharply at the end of the day.
Monday Night Light to moderate snow showers.
Tuesday Light to moderate snow showers.
Washington Cascades near and west of the Crest including Stevens, Snoqualmie and White Passes
Monday Moderate to heavy rain and high elevation snow in the north spreading southward during the afternoon and becoming heavy in most locations by the end of the day. Moderate to strong S-SW winds.
Monday Night Heavy rain and snow decreasing and becoming light to moderate snow showers by 10 PM. Heavier snow in convergence north possible north of Stevens Pass.
Tuesday Light to occasional moderate snow showers. Heavier snow in convergence north possible north of Stevens Pass.
East Slopes of the Washington Cascades
Monday Moderate to heavy rain and mid-to-high elevation snow in the north spreading southward during the afternoon and becoming heavy in most locations by the end of the day. Moderate S and S-SE crest-level winds, possibly becoming strong by afternoon in the south.
Monday Night Heavy rain and snow decreasing and becoming light snow showers by 10 PM. Heavier snow in convergence north possible north of Stevens Pass.
Tuesday Light snow showers. Heavier snow in convergence north possible north of Stevens Pass.
Mt. Hood
Monday Mostly cloudy with clouds thickening and lowering in the afternoon. Rain and snow arriving around 4 PM. Moderate SW winds becoming strong to very strong late in the day in the alpine.
Monday Night Heavy rain and high elevation snow along with strong to very strong SW winds during the evening . Alpine winds becoming moderate to strong as precipitation decreases to light snow showers after midnight.
Tuesday Light snow showers.

Snow/Freezing Level (ft)

Hurricane Ridge Mt. Baker Washington Pass Leavenworth Stevens Pass Snoqualmie Pass Mt. Rainier, Crystal & White Pass Mt. Hood
Monday Morning Snow Level * 7000' 4500' 5000' ' ' 6000' ' 7000'
Monday Afternoon Snow Level * 3500' 4500' 4500' ' ' 6000' ' 7000'
Monday Night Snow Level 2000' 2000' 2000' ' ' 2000' ' 3500'
Tuesday Morning Snow Level 2000' 2000' 2000' ' ' 2000' ' 2500'
Tuesday Afternoon Snow Level 1500' 1500' 1500' ' ' 1500' ' 2500'
Hurricane Ridge Elevation
Monday Morning Snow Level
7000'
(Easterly Flow *)
Monday Afternoon Snow Level
3500'
(Easterly Flow *)
Monday Night Snow Level
2000'
Tuesday Morning Snow Level
2000'
Tuesday Afternoon Snow Level
1500'
Tuesday Night Snow Level
1000'
Mt. Baker Elevation
Monday Morning Snow Level
4500'
(Easterly Flow *)
Monday Afternoon Snow Level
4500'
(Easterly Flow *)
Monday Night Snow Level
2000'
Tuesday Morning Snow Level
2000'
Tuesday Afternoon Snow Level
1500'
Tuesday Night Snow Level
1000'
Washington Pass Elevation
Monday Morning Snow Level
5000'
(Easterly Flow *)
Monday Afternoon Snow Level
4500'
(Easterly Flow *)
Monday Night Snow Level
2000'
Tuesday Morning Snow Level
2000'
Tuesday Afternoon Snow Level
1500'
Tuesday Night Snow Level
0'
Leavenworth Elevation
Monday Morning Snow Level
'
(Easterly Flow *)
Monday Afternoon Snow Level
'
(Easterly Flow *)
Monday Night Snow Level
'
Tuesday Morning Snow Level
'
Tuesday Afternoon Snow Level
'
Tuesday Night Snow Level
'
Stevens Pass Elevation
Monday Morning Snow Level
'
(Easterly Flow *)
Monday Afternoon Snow Level
'
(Easterly Flow *)
Monday Night Snow Level
'
Tuesday Morning Snow Level
'
Tuesday Afternoon Snow Level
'
Tuesday Night Snow Level
'
Snoqualmie Pass Elevation
Monday Morning Snow Level
6000'
(Easterly Flow *)
Monday Afternoon Snow Level
6000'
(Easterly Flow *)
Monday Night Snow Level
2000'
Tuesday Morning Snow Level
2000'
Tuesday Afternoon Snow Level
1500'
Tuesday Night Snow Level
1000'
Mt. Rainier & Crystal Elevation
Monday Morning Snow Level
'
(Easterly Flow *)
Monday Afternoon Snow Level
'
(Easterly Flow *)
Monday Night Snow Level
'
Tuesday Morning Snow Level
'
Tuesday Afternoon Snow Level
'
Tuesday Night Snow Level
'
Mt. Hood Elevation
Monday Morning Snow Level
7000'
(Easterly Flow *)
Monday Afternoon Snow Level
7000'
(Easterly Flow *)
Monday Night Snow Level
3500'
Tuesday Morning Snow Level
2500'
Tuesday Afternoon Snow Level
2500'
Tuesday Night Snow Level
2000'

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

Free Winds at 5000' (mph)

Hurricane Ridge Mt. Baker Stevens to Snoqualmie Pass Mt. Rainier Mt. Hood
Monday Morning SW 30 - 40 SSE 35 - 50 SW 35 - 50 --- - SW 25 - 35
Monday Afternoon SW 15 - 25 SW 20 - 30 SW 30 - 40 --- - SW 40 - 60
Monday Night WSW 20 - 30 WSW 20 - 30 WSW 20 - 30 --- - WSW 30 - 40
Tuesday Morning WSW 20 - 30 SW 20 - 30 WSW 20 - 30 --- - WSW 30 - 40
Tuesday Afternoon WSW 20 - 30 WSW 15 - 25 WSW 20 - 30 --- - WSW 25 - 35
Hurricane Ridge Elevation
Monday Morning SW 30 - 40
Monday Afternoon SW 15 - 25
Monday Night WSW 20 - 30
Tuesday Morning WSW 20 - 30
Tuesday Afternoon WSW 20 - 30
Tuesday Night W 10 - 20
Mt. Baker Elevation
Monday Morning SSE 35 - 50
Monday Afternoon SW 20 - 30
Monday Night WSW 20 - 30
Tuesday Morning SW 20 - 30
Tuesday Afternoon WSW 15 - 25
Tuesday Night W 10 - 20
Stevens and Snoqualmie Pass Elevation
Monday Morning SW 35 - 50
Monday Afternoon SW 30 - 40
Monday Night WSW 20 - 30
Tuesday Morning WSW 20 - 30
Tuesday Afternoon WSW 20 - 30
Tuesday Night W 15 - 25
Mt. Rainier Elevation
Monday Morning --- -
Monday Afternoon --- -
Monday Night --- -
Tuesday Morning --- -
Tuesday Afternoon --- -
Tuesday Night --- -
Mt. Hood Elevation
Monday Morning SW 25 - 35
Monday Afternoon SW 40 - 60
Monday Night WSW 30 - 40
Tuesday Morning WSW 30 - 40
Tuesday Afternoon WSW 25 - 35
Tuesday Night W 20 - 30
Hurricane Ridge Direction - Speed
Monday Morning SW 30 - 40
Monday Afternoon SW 15 - 25
Monday Night WSW 20 - 30
Tuesday Morning WSW 20 - 30
Tuesday Afternoon WSW 20 - 30
Tuesday Night W 10 - 20
Mt. Baker Direction - Speed
Monday Morning SSE 35 - 50
Monday Afternoon SW 20 - 30
Monday Night WSW 20 - 30
Tuesday Morning SW 20 - 30
Tuesday Afternoon WSW 15 - 25
Tuesday Night W 10 - 20
Stevens and Snoqualmie Pass Direction - Speed
Monday Morning SW 35 - 50
Monday Afternoon SW 30 - 40
Monday Night WSW 20 - 30
Tuesday Morning WSW 20 - 30
Tuesday Afternoon WSW 20 - 30
Tuesday Night W 15 - 25
Mt. Rainier Direction - Speed
Monday Morning --- -
Monday Afternoon --- -
Monday Night --- -
Tuesday Morning --- -
Tuesday Afternoon --- -
Tuesday Night --- -
Mt. Hood Direction - Speed
Monday Morning SW 25 - 35
Monday Afternoon SW 40 - 60
Monday Night WSW 30 - 40
Tuesday Morning WSW 30 - 40
Tuesday Afternoon WSW 25 - 35
Tuesday Night W 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
Monday Morning SW 50 - 70 SW 50 - 70 SW 60 - 80 --- - SW 50 - 70
Monday Afternoon SW 55 - 75 SW 55 - 75 SW 60 - 80 --- - SW 65 - 85
Monday Night WSW 40 - 60 WSW 45 - 65 WSW 45 - 65 --- - WSW 70 - 90
Tuesday Morning SW 30 - 40 SW 35 - 50 SW 40 - 60 --- - WSW 35 - 50
Tuesday Afternoon SW 30 - 40 SW 35 - 50 SW 40 - 60 --- - SW 35 - 50
Mt. Baker Direction - Speed
Monday Morning SW 50 - 70
Monday Afternoon SW 55 - 75
Monday Night WSW 40 - 60
Tuesday Morning SW 30 - 40
Tuesday Afternoon SW 30 - 40
Tuesday Night WSW 25 - 35
Washington Pass Direction - Speed
Monday Morning SW 50 - 70
Monday Afternoon SW 55 - 75
Monday Night WSW 45 - 65
Tuesday Morning SW 35 - 50
Tuesday Afternoon SW 35 - 50
Tuesday Night WSW 30 - 40
Stevens and Snoqualmie Pass Direction - Speed
Monday Morning SW 60 - 80
Monday Afternoon SW 60 - 80
Monday Night WSW 45 - 65
Tuesday Morning SW 40 - 60
Tuesday Afternoon SW 40 - 60
Tuesday Night W 30 - 40
Mt. Rainier Direction - Speed
Monday Morning --- -
Monday Afternoon --- -
Monday Night --- -
Tuesday Morning --- -
Tuesday Afternoon --- -
Tuesday Night --- -
Mt. Hood Direction - Speed
Monday Morning SW 50 - 70
Monday Afternoon SW 65 - 85
Monday Night WSW 70 - 90
Tuesday Morning WSW 35 - 50
Tuesday Afternoon SW 35 - 50
Tuesday Night W 40 - 60

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 28, 2018

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