Issued: 2:44 PM PDT Thursday, March 30, 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 Thursday & Saturday

No change to afternoon discussion: Post-frontal showers should generally wind down through mid-day as the longwave upper level trough pushes east of the Cascades this morning and upper level ridging begins to build offshore. A convergence zone(s) affecting Stevens and Snoqualmie Pass should give the occasional moderate shower this morning. Snow levels have fallen overnight into the 2500-3000 ft range. The highest snowfall totals overnight with the cooling were 8 inches at Mt. Baker and 5 inches at the top of Alpental and Stevens Pass. Generally 1-4 inches were seen elsewhere in the Olympics and Cascades. 

Showers should become more isolated in the afternoon over confined to the higher terrain. Sunbreaks are likely along the west slopes of the Cascades, Olympics and Mt. Hood with increasing sunshine likely along the east slopes of the Cascades.

The upper level ridging will quickly shift over the area Thursday night and shift inland on Friday. A weak front stalling around central Vancouver Island should spread increasing high clouds over the north Cascades and Olympics with sunnier skies expected further south. The front will sag far enough south late Friday night to spread some light rain and snow into the Olympics and north Cascades. 

Weather Forecast

Olympics
Thursday Afternoon

Mostly cloudy with afternoon sunbreaks. Isolated and light mountain showers. 

Thursday Night - Friday Morning

Becoming partly cloudy overnight. 

Friday Afternoon

Partly sunny with increasing high clouds in the afternoon.  

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

Mostly cloudy with afternoon sunbreaks. Isolated and light mountain showers. 

Thursday Night - Friday Morning

Becoming partly cloudy overnight. 

Friday Afternoon

Partly sunny north Cascades with increasing high clouds in the afternoon. Mostly sunny south Cascades.  

East slopes of the Washington Cascades
Thursday Morning

Partly to mostly cloudy with scattered light rain and snow showers near the Cascade crest. Cooler. 

Thursday Afternoon

Partly to mostly sunny. Isolated and light mountain showers near the Cascade crest. 

Thursday Night - Friday Morning

Becoming mostly clear overnight. 

Friday Afternoon

Partly sunny northeast Cascades with increasing high clouds in the afternoon. Mostly sunny southeast Cascades.  

Mt. Hood Area
Thursday Morning

Cloudy with scattered light to occasionally moderate rain and snow showers. Cooler. 

Thursday Afternoon - Thursday Evening

Mostly cloudy with scattered light rain and snow showers. Afternoon sunbreaks possible. 

Thursday Night - Friday Morning

Becoming partly cloudy overnight. 

Friday Afternoon

Mostly sunny and mild. 

Snow/Freezing Level (ft)

Hurricane Ridge Mt. Baker Washington Pass Leavenworth Stevens Pass Snoqualmie Pass Mt. Rainier, Crystal & White Pass Mt. Hood
Thursday Afternoon - Thursday Evening Snow Level 4000' 3500' 4000' ' ' 3500' ' 4000'
Thursday Night - Friday Morning Freezing Level 3500' 3000' 1500' ' ' 3000' ' 3500'
Friday Afternoon Freezing Level 6500' 5500' 6000' ' ' 6000' ' 8000'
Hurricane Ridge Elevation
Thursday Afternoon - Thursday Evening Snow Level
4000'
Thursday Night - Friday Morning Freezing Level
3500'
Friday Afternoon Freezing Level
6500'
Friday Night Snow Level
6500'
Mt. Baker Elevation
Thursday Afternoon - Thursday Evening Snow Level
3500'
Thursday Night - Friday Morning Freezing Level
3000'
Friday Afternoon Freezing Level
5500'
Friday Night Snow Level
4500'
Washington Pass Elevation
Thursday Afternoon - Thursday Evening Snow Level
4000'
Thursday Night - Friday Morning Freezing Level
1500'
Friday Afternoon Freezing Level
6000'
Friday Night Snow Level
4500'
Leavenworth Elevation
Thursday Afternoon - Thursday Evening Snow Level
'
Thursday Night - Friday Morning Freezing Level
'
Friday Afternoon Freezing Level
'
Friday Night Snow Level
'
Stevens Pass Elevation
Thursday Afternoon - Thursday Evening Snow Level
'
Thursday Night - Friday Morning Freezing Level
'
Friday Afternoon Freezing Level
'
Friday Night Snow Level
'
Snoqualmie Pass Elevation
Thursday Afternoon - Thursday Evening Snow Level
3500'
Thursday Night - Friday Morning Freezing Level
3000'
Friday Afternoon Freezing Level
6000'
Friday Night Snow Level
6500'
Mt. Rainier & Crystal Elevation
Thursday Afternoon - Thursday Evening Snow Level
'
Thursday Night - Friday Morning Freezing Level
'
Friday Afternoon Freezing Level
'
Friday Night Snow Level
'
Mt. Hood Elevation
Thursday Afternoon - Thursday Evening Snow Level
4000'
Thursday Night - Friday Morning Freezing Level
3500'
Friday Afternoon Freezing Level
8000'
Friday Night Snow Level
8000'

* 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

Saturday Saturday
Hurricane Ridge LT 0.10 LT 0.25
Mt Baker Ski Area LT 0.25 LT 0.25
Washington Pass LT 0.10 LT 0.10
Stevens Pass LT 0.25 LT 0.10
Snoqualmie Pass LT 0.25 LT 0.10
Mission Ridge LT 0.10 LT 0.10
Crystal Mt LT 0.10 LT 0.10
Paradise LT 0.25 LT 0.10
White Pass LT 0.10 LT 0.10
Mt Hood Meadows 0.25 - 0.50 LT 0.10
0.50 - 0.75 LT 0.10

Free Winds at 5000' (mph)

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

Extended Weather Synopsis for Saturday night through Saturday

The frontal system should quickly blow through the Cascades on Saturday with showers decreasing and becoming scattered in the afternoon. There should be more afternoon sunshine once again for the east slopes of the Cascades on Saturday. Alpine winds will be brisk out of the W-NW and snow levels should cool somewhat as well.

After a drying trend Saturday night, an upper level trough should move over the west coast, causing an increase in cloudiness and more scattered and generally light shower activity. An upper level ridge will build over the area late Sunday into Monday with dry weather expected. Forecast models disagree how much moisture will be trapped under the ridge affecting mainly the Olympics and west slopes of the Cascades with moist onshore flow at the surface.  

Extended Weather

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

Light rain and snow turning to light to occasionally moderate showers late morning, then showers becoming scattered in the afternoon. Mostly cloudy with afternoon sunbreaks west slopes of the Cascades, Olympics and Mt. Hood. Partly sunny east slopes. Slight cooling trend. 

Saturday Night

Partly to mostly cloudy with light showers ending overnight. 

Sunday

Mostly cloudy with light scattered showers. 

Sunday Night

Partly to mostly cloudy with light showers ending overnight. 

Monday

Partly to mostly sunny. 

Extended Snow/Freezing Levels

Mt. Baker Snoqualmie Pass Mt. Hood Easterly Flow *
Saturday Snow Level 4500' - 5500' 4500' - 5500' 6000' - 7000'
Saturday Night Snow Level 2000' - 3000' 3000' - 4000' 5500' - 6500'
Sunday - Sunday Night Snow Level 3000' - 4000' 3000' - 4000' 3500' - 4500'
Mt. Baker Elevation
Saturday Snow Level
4500' - 5500'
Saturday Night Snow Level
2000' - 3000'
Sunday - Sunday Night Snow Level
3000' - 4000'
Monday Freezing Level
3500' - 4500'
Snoqualmie Pass Elevation
Saturday Snow Level
4500' - 5500'
Saturday Night Snow Level
3000' - 4000'
Sunday - Sunday Night Snow Level
3000' - 4000'
Monday Freezing Level
4000' - 5000'
Mt. Hood Elevation
Saturday Snow Level
6000' - 7000'
Saturday Night Snow Level
5500' - 6500'
Sunday - Sunday Night Snow Level
3500' - 4500'
Monday Freezing Level
5000' - 6000'

* 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 Mar 30, 2017

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