Issued: 1:43 PM PST Tuesday, January 31, 2017
by Dennis D'Amico

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

Weather Synopsis for Tuesday & Wednesday

Warm frontal moisture overriding an E-W oriented baroclinic zone near the WA/OR border will continue to produce light snow for the south and central Washington Cascades and Mt. Hood this morning. This boundary is expected to shift south today bringing steady light snow to an end. Light and scattered mountain showers currently affecting the mountain loop area and Stevens and Snoqualmie Passes should shift a bit south and continue through the afternoon with mostly clear conditions over the north Cascades.

A brief shot of arctic air will begin filtering into the region later today and tonight as strong high pressure currently situated over British Columbia slides south and into eastern Washington and Oregon over the next two days. While drier and sunnier conditions are expected on Wednesday outside of Mt. Hood and the far south Washington Cascades, easterly offshore flow will begin to really crank up Wednesday afternoon and night beginning a period of moderate easterly winds.  

Weather Forecast

Olympics
Washington Cascades near and west of the crest including Stevens, Snoqualmie, and White Passes
Tuesday Afternoon

Mostly sunny north Cascades. Partly to mostly cloudy central and south Washington Cascades with scattered light snow showers. 

Tuesday Night

Clear north Cascades. Partly to mostly clear central and south Cascades with isolated light snow showers ending in the evening. Cold. 

East slopes of the Washington Cascades
Tuesday Afternoon - Tuesday Evening

Partly cloudy northeast Cascades. Mostly cloudy central and south Washington Cascades with isolated light snow showers. 

Tuesday Night

Mostly clear and cold. 

Mt. Hood Area
Tuesday

Cloudy with periods of light snow becoming mostly cloudy with scattered light snow showers in the afternoon. Cooling trend. Strong alpine winds this morning easing a bit in the afternoon. 

Tuesday Night - Wednesday Morning

Mostly cloudy. Colder. 

Snow/Freezing Level (ft)

Hurricane Ridge Mt. Baker Washington Pass Leavenworth Stevens Pass Snoqualmie Pass Mt. Rainier, Crystal & White Pass Mt. Hood
Tuesday Afternoon Snow Level 500' 500' 0' ' ' 1000' ' 2500'
Hurricane Ridge Elevation
Tuesday Afternoon Snow Level
500'
Tuesday Night - Wednesday Night Freezing Level
0'
(Easterly Flow *)
Mt. Baker Elevation
Tuesday Afternoon Snow Level
500'
Tuesday Night - Wednesday Night Freezing Level
0'
(Easterly Flow *)
Washington Pass Elevation
Tuesday Afternoon Snow Level
0'
Tuesday Night - Wednesday Night Freezing Level
0'
(Easterly Flow *)
Leavenworth Elevation
Tuesday Afternoon Snow Level
'
Tuesday Night - Wednesday Night Freezing Level
'
(Easterly Flow *)
Stevens Pass Elevation
Tuesday Afternoon Snow Level
'
Tuesday Night - Wednesday Night Freezing Level
'
(Easterly Flow *)
Snoqualmie Pass Elevation
Tuesday Afternoon Snow Level
1000'
Tuesday Night - Wednesday Night Freezing Level
0'
(Easterly Flow *)
Mt. Rainier & Crystal Elevation
Tuesday Afternoon Snow Level
'
Tuesday Night - Wednesday Night Freezing Level
'
(Easterly Flow *)
Mt. Hood Elevation
Tuesday Afternoon Snow Level
2500'
Tuesday Night - Wednesday Night Freezing Level
0'
(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

Wednesday Wednesday
Hurricane Ridge LT 0.10 LT 0.10
Mt Baker Ski Area LT 0.10 LT 0.10
Washington Pass LT 0.10 LT 0.10
Stevens Pass LT 0.10 LT 0.10
Snoqualmie Pass LT 0.10 LT 0.10
Mission Ridge LT 0.25 LT 0.10
Crystal Mt LT 0.10 LT 0.10
Paradise LT 0.10 LT 0.10
White Pass LT 0.10 LT 0.10
Mt Hood Meadows LT 0.10 LT 0.25
LT 0.10 LT 0.25

Free Winds at 5000' (mph)

Hurricane Ridge Mt. Baker Stevens to Snoqualmie Pass Mt. Rainier Mt. Hood
Tuesday Afternoon NE 10 - 20 NE 10 - 20 E 0 - 10 --- - VAR 0 - 10
Tuesday Night - Wednesday Morning NE 10 - 20 NE 10 - 20 E 5 - 15 --- - E 5 - 15
Hurricane Ridge Elevation
Tuesday Afternoon NE 10 - 20
Tuesday Night - Wednesday Morning NE 10 - 20
Wednesday Afternoon - Wednesday Night E 15 - 25
Mt. Baker Elevation
Tuesday Afternoon NE 10 - 20
Tuesday Night - Wednesday Morning NE 10 - 20
Wednesday Afternoon - Wednesday Night ENE 10 - 20
Stevens and Snoqualmie Pass Elevation
Tuesday Afternoon E 0 - 10
Tuesday Night - Wednesday Morning E 5 - 15
Wednesday Afternoon - Wednesday Night E 20 - 30
Mt. Rainier Elevation
Tuesday Afternoon --- -
Tuesday Night - Wednesday Morning --- -
Wednesday Afternoon - Wednesday Night --- -
Mt. Hood Elevation
Tuesday Afternoon VAR 0 - 10
Tuesday Night - Wednesday Morning E 5 - 15
Wednesday Afternoon - Wednesday Night E 15 - 25
Hurricane Ridge Direction - Speed
Tuesday Afternoon NE 10 - 20
Tuesday Night - Wednesday Morning NE 10 - 20
Wednesday Afternoon - Wednesday Night E 15 - 25
Mt. Baker Direction - Speed
Tuesday Afternoon NE 10 - 20
Tuesday Night - Wednesday Morning NE 10 - 20
Wednesday Afternoon - Wednesday Night ENE 10 - 20
Stevens and Snoqualmie Pass Direction - Speed
Tuesday Afternoon E 0 - 10
Tuesday Night - Wednesday Morning E 5 - 15
Wednesday Afternoon - Wednesday Night E 20 - 30
Mt. Rainier Direction - Speed
Tuesday Afternoon --- -
Tuesday Night - Wednesday Morning --- -
Wednesday Afternoon - Wednesday Night --- -
Mt. Hood Direction - Speed
Tuesday Afternoon VAR 0 - 10
Tuesday Night - Wednesday Morning E 5 - 15
Wednesday Afternoon - Wednesday Night E 15 - 25

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
Tuesday Afternoon NE 5 - 15 N 5 - 15 NW 0 - 10 --- - W 25 - 35
Tuesday Night - Wednesday Morning ENE 15 - 25 NE 10 - 20 E 5 - 15 --- - SW 20 - 30
Mt. Baker Direction - Speed
Tuesday Afternoon NE 5 - 15
Tuesday Night - Wednesday Morning ENE 15 - 25
Wednesday Afternoon - Wednesday Night E 15 - 25
Washington Pass Direction - Speed
Tuesday Afternoon N 5 - 15
Tuesday Night - Wednesday Morning NE 10 - 20
Wednesday Afternoon - Wednesday Night E 10 - 20
Stevens and Snoqualmie Pass Direction - Speed
Tuesday Afternoon NW 0 - 10
Tuesday Night - Wednesday Morning E 5 - 15
Wednesday Afternoon - Wednesday Night E 10 - 20
Mt. Rainier Direction - Speed
Tuesday Afternoon --- -
Tuesday Night - Wednesday Morning --- -
Wednesday Afternoon - Wednesday Night --- -
Mt. Hood Direction - Speed
Tuesday Afternoon W 25 - 35
Tuesday Night - Wednesday Morning SW 20 - 30
Wednesday Afternoon - Wednesday Night SW 10 - 20

Extended Weather Synopsis for Wednesday night through Wednesday

The pattern of cold and clear offshore flow will continue through Thursday with east winds peaking in intensity Thursday morning at Cascades Pass level and at crest level especially for the south and central Washington Cascades. Down at Mt. Hood, moderate east winds are also expected up to mid-mountain but skies should remain cloudy.  The upper level low off the California coast will meander closer to the coastline on Thursday night with showers and increasing clouds finally beginning to rotate northward. Temperatures will begin to moderate Friday but it won't be until Saturday that relatively milder Pacific air mixes inland. A deep upper level low in the northern branch of the jet is forecast to dive off of the southern B.C. coast Saturday, directing heavier showers and Pacific air into the region and switching the flow in the Passes from east to west.  

Extended Weather

Olympics, Washington Cascades and Mt. Hood
Thursday

Mostly sunny and cold Olympics and Washington Cascades. Moderate to occasionally strong east winds Cascade Passes and south and central Cascades up to crest level. Mostly cloudy with breezy east winds Mt. Hood. 

Thursday Night - Friday Morning

Increasing clouds with light to occasionally moderate snow showers Mt. Hood spreading northward overnight.  

Friday Afternoon - Saturday

Cloudy with light to moderate rain and snow showers, occasionally heavy along the west slopes and Mt. Hood. Slow warming trend. 

Extended Snow/Freezing Levels

Mt. Baker Snoqualmie Pass Mt. Hood Easterly Flow *
Thursday - Thursday Night Freezing Level 0' - 1000' 0' - 0' 0' - 0' *
Friday Snow Level 1000' - 2000' 500' - 1500' 1500' - 2500' *
Friday Night Snow Level 1000' - 2000' 2000' - 4000' 5000' - 6000' *
Mt. Baker Elevation
Thursday - Thursday Night Freezing Level
0' - 1000'
(Easterly Flow *)
Friday Snow Level
1000' - 2000'
(Easterly Flow *)
Friday Night Snow Level
1000' - 2000'
(Easterly Flow *)
Saturday Snow Level
1500' - 2500'
Snoqualmie Pass Elevation
Thursday - Thursday Night Freezing Level
0' - 0'
(Easterly Flow *)
Friday Snow Level
500' - 1500'
(Easterly Flow *)
Friday Night Snow Level
2000' - 4000'
(Easterly Flow *)
Saturday Snow Level
2000' - 3000'
Mt. Hood Elevation
Thursday - Thursday Night Freezing Level
0' - 0'
(Easterly Flow *)
Friday Snow Level
1500' - 2500'
(Easterly Flow *)
Friday Night Snow Level
5000' - 6000'
(Easterly Flow *)
Saturday Snow Level
4500' - 5500'

* 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 Jan 31, 2017

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.