Issued: 7:39 AM PST Wednesday, January 10, 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 Wednesday & Friday

A shallow trough over Idaho with a broad ridge to the west keeps us in a cool W-NW flow on Wednesday morning with light snow showers and some convergence zone activity lingering in the North Cascades. A weak warm frontal feature should lift northward and bring additional light rain and snow showers to the Mt. Hood and southern Cascades areas this morning and into the central Cascades this afternoon before fizzling out.

Tonight, a stronger upper trough and low pressure center will be approaching our coastal waters with a warm front moving over the Olympics and and southern Cascades in the early morning hours.

On Thursday a low tracking toward Northwest Washington or southern Vancouver Island will be accompanied by a strong warm front followed by a cold front. The system will bring very stormy weather with strong to very strong shifting alpine winds and moderate to heavy rain and snow and rising freezing levels. Expect snow in the passes tonight into tomorrow morning with Snoqualmie pass changing to rain in the early to mid afternoon and Stevens pass possibly changing to rain at this time before an eventual return to all snow at Stevens Pass in the evening hours. 

Weather Forecast

Olympics
Wednesday Increasing very light rain or snow showers.
Wednesday Night Increasing light rain and snow.
Thursday Increasing light to moderate rain and snow becoming showery in the afternoon.
Washington Cascades near and west of the Crest including Stevens, Snoqualmie and White Passes
Wednesday Decreasing light snow showers and convergence zone activity in the North Cascades this morning with occasional showers in the afternoon. In the Central and South, increasing light rain and snow showers.
Wednesday Night Increasing light rain and snow in the north; increasing light rain and snow becoming moderate in the central and south.
Thursday Very stormy. Moderate to heavy rain and snow. Heaviest Mt. Rainier.
East Slopes of the Washington Cascades
Wednesday Very light rain or snow showers.
Wednesday Night Increasing light rain and snow in the north; increasing light rain and snow becoming moderate in the central and south.
Thursday Very stormy. Moderate rain and snow.
Mt. Hood
Wednesday Light rain and snow showers.
Wednesday Night Increasing light to moderate rain and snow showers.
Thursday Moderate to heavy rain and snow.

Snow/Freezing Level (ft)

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

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

Free Winds at 5000' (mph)

Hurricane Ridge Mt. Baker Stevens to Snoqualmie Pass Mt. Rainier Mt. Hood
Wednesday Morning SW 10 - 20 SW 10 - 20 W 15 - 25 --- - W 20 - 30
Wednesday Afternoon SW 5 - 15 SW 5 - 15 W 5 - 15 --- - WSW 10 - 20
Wednesday Night S 15 - 25 SE 5 - 15 S 20 - 30 --- - SW 35 - 45
Thursday Morning SSW 30 - 40 E 10 - 20 ESE 20 - 30 --- - SW 50 - 70
Thursday Afternoon SW 15 - 25 S 15 - 25 SW 35 - 45 --- - SW 50 - 70
Hurricane Ridge Elevation
Wednesday Morning SW 10 - 20
Wednesday Afternoon SW 5 - 15
Wednesday Night S 15 - 25
Thursday Morning SSW 30 - 40
Thursday Afternoon SW 15 - 25
Thursday Night WSW 15 - 25
Mt. Baker Elevation
Wednesday Morning SW 10 - 20
Wednesday Afternoon SW 5 - 15
Wednesday Night SE 5 - 15
Thursday Morning E 10 - 20
Thursday Afternoon S 15 - 25
Thursday Night WSW 15 - 25
Stevens and Snoqualmie Pass Elevation
Wednesday Morning W 15 - 25
Wednesday Afternoon W 5 - 15
Wednesday Night S 20 - 30
Thursday Morning ESE 20 - 30
Thursday Afternoon SW 35 - 45
Thursday Night WSW 40 - 60
Mt. Rainier Elevation
Wednesday Morning --- -
Wednesday Afternoon --- -
Wednesday Night --- -
Thursday Morning --- -
Thursday Afternoon --- -
Thursday Night --- -
Mt. Hood Elevation
Wednesday Morning W 20 - 30
Wednesday Afternoon WSW 10 - 20
Wednesday Night SW 35 - 45
Thursday Morning SW 50 - 70
Thursday Afternoon SW 50 - 70
Thursday Night WSW 40 - 60
Hurricane Ridge Direction - Speed
Wednesday Morning SW 10 - 20
Wednesday Afternoon SW 5 - 15
Wednesday Night S 15 - 25
Thursday Morning SSW 30 - 40
Thursday Afternoon SW 15 - 25
Thursday Night WSW 15 - 25
Mt. Baker Direction - Speed
Wednesday Morning SW 10 - 20
Wednesday Afternoon SW 5 - 15
Wednesday Night SE 5 - 15
Thursday Morning E 10 - 20
Thursday Afternoon S 15 - 25
Thursday Night WSW 15 - 25
Stevens and Snoqualmie Pass Direction - Speed
Wednesday Morning W 15 - 25
Wednesday Afternoon W 5 - 15
Wednesday Night S 20 - 30
Thursday Morning ESE 20 - 30
Thursday Afternoon SW 35 - 45
Thursday Night WSW 40 - 60
Mt. Rainier Direction - Speed
Wednesday Morning --- -
Wednesday Afternoon --- -
Wednesday Night --- -
Thursday Morning --- -
Thursday Afternoon --- -
Thursday Night --- -
Mt. Hood Direction - Speed
Wednesday Morning W 20 - 30
Wednesday Afternoon WSW 10 - 20
Wednesday Night SW 35 - 45
Thursday Morning SW 50 - 70
Thursday Afternoon SW 50 - 70
Thursday Night WSW 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.

Free Winds at 9000' (mph)

Mt. Baker Washington Pass Stevens to Snoqualmie Pass Mt. Rainier Mt. Hood
Wednesday Morning W 29 - 39 W 25 - 35 W 30 - 40 --- - W 25 - 35
Wednesday Afternoon W 25 - 35 W 20 - 30 W 30 - 40 --- - W 25 - 35
Wednesday Night SW 25 - 35 WSW 25 - 35 WSW 35 - 45 --- - WSW 55 - 75
Thursday Morning SSW 30 - 40 S 30 - 40 WSW 55 - 75 --- - WSW 60 - 80
Thursday Afternoon WSW 30 - 40 WSW 40 - 60 WSW 50 - 70 --- - WSW 65 - 85
Mt. Baker Direction - Speed
Wednesday Morning W 29 - 39
Wednesday Afternoon W 25 - 35
Wednesday Night SW 25 - 35
Thursday Morning SSW 30 - 40
Thursday Afternoon WSW 30 - 40
Thursday Night WSW 20 - 30
Washington Pass Direction - Speed
Wednesday Morning W 25 - 35
Wednesday Afternoon W 20 - 30
Wednesday Night WSW 25 - 35
Thursday Morning S 30 - 40
Thursday Afternoon WSW 40 - 60
Thursday Night WSW 25 - 35
Stevens and Snoqualmie Pass Direction - Speed
Wednesday Morning W 30 - 40
Wednesday Afternoon W 30 - 40
Wednesday Night WSW 35 - 45
Thursday Morning WSW 55 - 75
Thursday Afternoon WSW 50 - 70
Thursday Night WSW 45 - 65
Mt. Rainier Direction - Speed
Wednesday Morning --- -
Wednesday Afternoon --- -
Wednesday Night --- -
Thursday Morning --- -
Thursday Afternoon --- -
Thursday Night --- -
Mt. Hood Direction - Speed
Wednesday Morning W 25 - 35
Wednesday Afternoon W 25 - 35
Wednesday Night WSW 55 - 75
Thursday Morning WSW 60 - 80
Thursday Afternoon WSW 65 - 85
Thursday Night WSW 45 - 65

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 8, 2018

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.