Issued: 7:28 AM PST Wednesday, January 31, 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 Wednesday & Tuesday

A 145 kt jet will move over the area in in cool W-NW flow aloft today. Orographic showers in westerly flow will squeeze out some light snowfall accumulations at low snow levels especially for the west slopes of the Cascades. Light shower activity seen today and tonight should wane Thursday morning, but warm frontal precipitation associated with a parent low in the NE Pacific will spread light precipitation over the Cascades by Thursday afternoon.

An upper level ridge will begin building offshore outside of 130W today. Over the next 48 hours, this ridge will slide slightly eastward and begin to bring warmer air into the region. Snow levels should gradually rise during the day on Thursday, and rise further overnight as precipitation intensifies and an occluded front passes through the Cascades. Rain will push into mid-elevations (near treeline) by early Friday morning for all areas.  Precipitation looks heaviest from Snoqualmie Pass to Mt. Hood Thursday night. 

Weather Forecast

Olympics
Wednesday Cloudy with light snow showers.
Wednesday Night Mostly cloudy with light snow showers.
Thursday Mostly cloudy with scattered light snow showers becoming light rain and snow mid-day. Warming trend.
Washington Cascades near and west of the Crest including Stevens, Snoqualmie and White Passes
Wednesday Cloudy with light snow showers.
Wednesday Night Cloudy with light snow showers.
Thursday Mostly cloudy with scattered light snow showers becoming light rain and snow in the afternoon. Slow warming trend.
East Slopes of the Washington Cascades
Wednesday Cloudy with light snow showers.
Wednesday Night Mostly cloudy with light snow showers.
Thursday Mostly cloudy with scattered light snow showers becoming light snow in the afternoon. Slow warming trend.
Mt. Hood
Wednesday Cloudy with light snow showers.
Wednesday Night Mostly cloudy with light snow showers.
Thursday Mostly cloudy with scattered light snow showers becoming light rain and snow in the afternoon. Warming trend.

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 1000' 500' 500' ' ' 1000' ' 2000'
Wednesday Afternoon Snow Level 2000' 1500' 1000' ' ' 2000' ' 3000'
Wednesday Night Snow Level 2500' 2000' 1000' ' ' 2000' ' 3000'
Thursday Morning Snow Level 3500' 2500' 2000' ' ' 2500' ' 4000'
Thursday Afternoon Snow Level 4500' 3500' 3500' ' ' 4000' ' 6000'
Hurricane Ridge Elevation
Wednesday Morning Snow Level
1000'
Wednesday Afternoon Snow Level
2000'
Wednesday Night Snow Level
2500'
Thursday Morning Snow Level
3500'
Thursday Afternoon Snow Level
4500'
Thursday Night Snow Level
6500'
Mt. Baker Elevation
Wednesday Morning Snow Level
500'
Wednesday Afternoon Snow Level
1500'
Wednesday Night Snow Level
2000'
Thursday Morning Snow Level
2500'
Thursday Afternoon Snow Level
3500'
Thursday Night Snow Level
5000'
Washington Pass Elevation
Wednesday Morning Snow Level
500'
Wednesday Afternoon Snow Level
1000'
Wednesday Night Snow Level
1000'
Thursday Morning Snow Level
2000'
Thursday Afternoon Snow Level
3500'
Thursday Night Snow Level
4000'
Leavenworth Elevation
Wednesday Morning Snow Level
'
Wednesday Afternoon Snow Level
'
Wednesday Night Snow Level
'
Thursday Morning Snow Level
'
Thursday Afternoon Snow Level
'
Thursday Night Snow Level
'
Stevens Pass Elevation
Wednesday Morning Snow Level
'
Wednesday Afternoon Snow Level
'
Wednesday Night Snow Level
'
Thursday Morning Snow Level
'
Thursday Afternoon Snow Level
'
Thursday Night Snow Level
'
Snoqualmie Pass Elevation
Wednesday Morning Snow Level
1000'
Wednesday Afternoon Snow Level
2000'
Wednesday Night Snow Level
2000'
Thursday Morning Snow Level
2500'
Thursday Afternoon Snow Level
4000'
Thursday Night Snow Level
5500'
Mt. Rainier & Crystal Elevation
Wednesday Morning Snow Level
'
Wednesday Afternoon Snow Level
'
Wednesday Night Snow Level
'
Thursday Morning Snow Level
'
Thursday Afternoon Snow Level
'
Thursday Night Snow Level
'
Mt. Hood Elevation
Wednesday Morning Snow Level
2000'
Wednesday Afternoon Snow Level
3000'
Wednesday Night Snow Level
3000'
Thursday Morning Snow Level
4000'
Thursday Afternoon Snow Level
6000'
Thursday Night Snow Level
7500'

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

Free Winds at 5000' (mph)

Hurricane Ridge Mt. Baker Stevens to Snoqualmie Pass Mt. Rainier Mt. Hood
Wednesday Morning SW 5 - 15 SW 5 - 15 WSW 10 - 20 --- - W 10 - 20
Wednesday Afternoon S 5 - 15 S 0 - 10 SW 5 - 15 --- - SW 5 - 15
Wednesday Night SW 10 - 20 SSW 10 - 20 SW 10 - 20 --- - WSW 5 - 15
Thursday Morning S 0 - 10 SW 0 - 10 SW 5 - 15 --- - SW 0 - 10
Thursday Afternoon S 10 - 20 S 5 - 15 S 5 - 15 --- - SW 10 - 20
Hurricane Ridge Elevation
Wednesday Morning SW 5 - 15
Wednesday Afternoon S 5 - 15
Wednesday Night SW 10 - 20
Thursday Morning S 0 - 10
Thursday Afternoon S 10 - 20
Thursday Night SW 10 - 20
Mt. Baker Elevation
Wednesday Morning SW 5 - 15
Wednesday Afternoon S 0 - 10
Wednesday Night SSW 10 - 20
Thursday Morning SW 0 - 10
Thursday Afternoon S 5 - 15
Thursday Night SSW 5 - 15
Stevens and Snoqualmie Pass Elevation
Wednesday Morning WSW 10 - 20
Wednesday Afternoon SW 5 - 15
Wednesday Night SW 10 - 20
Thursday Morning SW 5 - 15
Thursday Afternoon S 5 - 15
Thursday Night SW 15 - 25
Mt. Rainier Elevation
Wednesday Morning --- -
Wednesday Afternoon --- -
Wednesday Night --- -
Thursday Morning --- -
Thursday Afternoon --- -
Thursday Night --- -
Mt. Hood Elevation
Wednesday Morning W 10 - 20
Wednesday Afternoon SW 5 - 15
Wednesday Night WSW 5 - 15
Thursday Morning SW 0 - 10
Thursday Afternoon SW 10 - 20
Thursday Night SW 25 - 35
Hurricane Ridge Direction - Speed
Wednesday Morning SW 5 - 15
Wednesday Afternoon S 5 - 15
Wednesday Night SW 10 - 20
Thursday Morning S 0 - 10
Thursday Afternoon S 10 - 20
Thursday Night SW 10 - 20
Mt. Baker Direction - Speed
Wednesday Morning SW 5 - 15
Wednesday Afternoon S 0 - 10
Wednesday Night SSW 10 - 20
Thursday Morning SW 0 - 10
Thursday Afternoon S 5 - 15
Thursday Night SSW 5 - 15
Stevens and Snoqualmie Pass Direction - Speed
Wednesday Morning WSW 10 - 20
Wednesday Afternoon SW 5 - 15
Wednesday Night SW 10 - 20
Thursday Morning SW 5 - 15
Thursday Afternoon S 5 - 15
Thursday Night SW 15 - 25
Mt. Rainier Direction - Speed
Wednesday Morning --- -
Wednesday Afternoon --- -
Wednesday Night --- -
Thursday Morning --- -
Thursday Afternoon --- -
Thursday Night --- -
Mt. Hood Direction - Speed
Wednesday Morning W 10 - 20
Wednesday Afternoon SW 5 - 15
Wednesday Night WSW 5 - 15
Thursday Morning SW 0 - 10
Thursday Afternoon SW 10 - 20
Thursday Night SW 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
Wednesday Morning W 15 - 25 W 20 - 30 W 25 - 35 --- - W 30 - 40
Wednesday Afternoon SW 15 - 25 W 15 - 25 WSW 20 - 30 --- - WNW 30 - 40
Wednesday Night WSW 20 - 30 WSW 25 - 35 W 25 - 35 --- - WNW 25 - 35
Thursday Morning W 20 - 30 WSW 20 - 30 W 25 - 35 --- - W 20 - 30
Thursday Afternoon WSW 25 - 35 WSW 20 - 30 WSW 30 - 40 --- - W 30 - 40
Mt. Baker Direction - Speed
Wednesday Morning W 15 - 25
Wednesday Afternoon SW 15 - 25
Wednesday Night WSW 20 - 30
Thursday Morning W 20 - 30
Thursday Afternoon WSW 25 - 35
Thursday Night WSW 15 - 25
Washington Pass Direction - Speed
Wednesday Morning W 20 - 30
Wednesday Afternoon W 15 - 25
Wednesday Night WSW 25 - 35
Thursday Morning WSW 20 - 30
Thursday Afternoon WSW 20 - 30
Thursday Night WSW 20 - 30
Stevens and Snoqualmie Pass Direction - Speed
Wednesday Morning W 25 - 35
Wednesday Afternoon WSW 20 - 30
Wednesday Night W 25 - 35
Thursday Morning W 25 - 35
Thursday Afternoon WSW 30 - 40
Thursday Night W 30 - 40
Mt. Rainier Direction - Speed
Wednesday Morning --- -
Wednesday Afternoon --- -
Wednesday Night --- -
Thursday Morning --- -
Thursday Afternoon --- -
Thursday Night --- -
Mt. Hood Direction - Speed
Wednesday Morning W 30 - 40
Wednesday Afternoon WNW 30 - 40
Wednesday Night WNW 25 - 35
Thursday Morning W 20 - 30
Thursday Afternoon W 30 - 40
Thursday Night W 40 - 50

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 30, 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.