Issued: 4:21 PM PDT Friday, April 13, 2018
by Robert Hahn

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

Weather Synopsis for Friday & Friday

A moisture-laden storm impacts the Pacific NW. As of Friday afternoon, most of the Pacific Northwest sits in the warm sector of the storm with warm air continuing to displace the cooler air prior to the warm front. Temperatures will peak late in the day on Friday. Moderate to heavy rain bands are streaming into the mountains of Washington State with precipitation decreasing at Mt. Hood. Mt. Baker and Paradise will continue to be favored by this SW flow pattern while Hurricane Ridge and Crystal are mostly rain-shadowed. Snoqualmie, Stevens, and Paradise have generally seen a changeover to rain by mid-afternoon on Friday. Cold-air pooling has kept the Baker base as snow early on Friday afternoon, but the cold pool may get scoured out with the southwest flow during the late afternoon, allowing the snow level to rise. Crest-level winds will be moderate to occasionally strong.

The cold frontal rainband is now impacting the Olympics and will bring cooling to the Olympics during the evening hours on Friday and to the North Cascades during the early morning hours on Saturday, so the Baker base should return to all snow by Saturday morning. 

On Saturday, the weakening cold frontal rainband remains over Washington state as the upper low drops gradually southward offshore of British Columbia. The rainband will bringing light to occasional moderate rain and snow, but a wave riding up the front will bring additional moderate to heavy rain and snow to Washington's mountains along with increased moderate crest-level winds late Saturday through Saturday evening with light to moderate rain and snow showers after midnight along with significantly cooling temperatures and slackening winds as the front drops southward into Oregon, focusing the precipitation on the Mt. Hood region.

Weather Forecast

Olympics
Friday Mostly cloudy with light rain or high elevation snow. Moderate SSW winds.
Friday Night Light rain and snow. Moderate SSW winds decreasing toward morning. Cooling temperatures.
Saturday Light rain and snow mainly in the afternoon.
Washington Cascades near and west of the Crest including Stevens, Snoqualmie and White Passes
Friday Bands of moderate to heavy rain and snow with rising snow levels and increasing moderate to occasionally strong winds. Paradise and Mt. Baker will receive the heaviest precipitation while Crystal will see mostly light precipitation.
Friday Night Paradise and Mt. Baker will receive moderate to heavy rain and snow, while Crystal and the Cascade Passes will see light to moderate precipitation. Moderate to occasionally strong winds gradually decreasing.
Saturday Light rain and snow will continue in most areas, but precipitation will increase late in the day into the moderate to occasionally heavy range with increasing snow levels. Moderate S-SW winds, increasing int he afternoon.
East Slopes of the Washington Cascades
Friday Moderate rain and snow with increasing moderate to occasionally strong SW winds. Rising snow levels throughout the day.
Friday Night Moderate rain and snow with moderate to occasionally strong SW winds, decreasing after midnight. Slightly lowering snow levels.
Saturday Light rain and snow, increasing late in the day.
Mt. Hood
Friday Moderate rain and snow, decreasing late in the day. Moderate to occasionally strong SW winds.
Friday Night Mostly cloudy with periods of light rain and snow.
Saturday Molstly cloudy with periods of light 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
Friday Afternoon Snow Level 5000' 4000' 5000' ' ' 5000' ' 5000'
Friday Night Snow Level 4000' 4000' 4000' ' ' 4500' ' 4000'
Saturday Morning Snow Level 4000' 4000' 5000' ' ' 4500' ' 5000'
Saturday Afternoon Snow Level 3500' 4000' 5000' ' ' 5000' ' 5000'
Hurricane Ridge Elevation
Friday Afternoon Snow Level
5000'
Friday Night Snow Level
4000'
Saturday Morning Snow Level
4000'
Saturday Afternoon Snow Level
3500'
Saturday Night Snow Level
2500'
Mt. Baker Elevation
Friday Afternoon Snow Level
4000'
Friday Night Snow Level
4000'
Saturday Morning Snow Level
4000'
Saturday Afternoon Snow Level
4000'
Saturday Night Snow Level
3000'
Washington Pass Elevation
Friday Afternoon Snow Level
5000'
Friday Night Snow Level
4000'
Saturday Morning Snow Level
5000'
Saturday Afternoon Snow Level
5000'
Saturday Night Snow Level
3500'
Leavenworth Elevation
Friday Afternoon Snow Level
'
Friday Night Snow Level
'
Saturday Morning Snow Level
'
Saturday Afternoon Snow Level
'
Saturday Night Snow Level
'
Stevens Pass Elevation
Friday Afternoon Snow Level
'
Friday Night Snow Level
'
Saturday Morning Snow Level
'
Saturday Afternoon Snow Level
'
Saturday Night Snow Level
'
Snoqualmie Pass Elevation
Friday Afternoon Snow Level
5000'
Friday Night Snow Level
4500'
Saturday Morning Snow Level
4500'
Saturday Afternoon Snow Level
5000'
Saturday Night Snow Level
4000'
Mt. Rainier & Crystal Elevation
Friday Afternoon Snow Level
'
Friday Night Snow Level
'
Saturday Morning Snow Level
'
Saturday Afternoon Snow Level
'
Saturday Night Snow Level
'
Mt. Hood Elevation
Friday Afternoon Snow Level
5000'
Friday Night Snow Level
4000'
Saturday Morning Snow Level
5000'
Saturday Afternoon Snow Level
5000'
Saturday 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 - 0.50
Mt Baker Ski Area 1.50 - 2.00 0 - 1.00
Washington Pass 0.50 - 0.75 0.50 - 0.75
Stevens Pass 0 - 1.00 0 - 0.75
Snoqualmie Pass 1.00 - 1.50 0 - 1.00
Mission Ridge LT 0.25 LT 0.25
Crystal Mt 0.50 - 0.75 0 - 0.50
Paradise 2.00 - 3.00 1.50 - 2.50
White Pass 0.75 - 1.00 0.25 - 0.50
Mt Hood Meadows 1.00 - 1.50 0.25 - 0.50
1.50 - 2.00 0.25 - 0.50

Free Winds at 5000' (mph)

Hurricane Ridge Mt. Baker Stevens to Snoqualmie Pass Mt. Rainier Mt. Hood
Friday Afternoon SW 20 - 30 S 25 - 35 SW 30 - 40 --- - SW 30 - 40
Friday Night SW 20 - 30 SW 20 - 30 SW 30 - 40 --- - SW 25 - 35
Saturday Morning SW 10 - 20 S 10 - 20 S 20 - 30 --- - SSW 15 - 25
Saturday Afternoon SSW 5 - 15 SSW 10 - 20 SSW 15 - 25 --- - SSW 20 - 30
Hurricane Ridge Elevation
Friday Afternoon SW 20 - 30
Friday Night SW 20 - 30
Saturday Morning SW 10 - 20
Saturday Afternoon SSW 5 - 15
Saturday Night W 0 - 10
Mt. Baker Elevation
Friday Afternoon S 25 - 35
Friday Night SW 20 - 30
Saturday Morning S 10 - 20
Saturday Afternoon SSW 10 - 20
Saturday Night VAR 0 - 10
Stevens and Snoqualmie Pass Elevation
Friday Afternoon SW 30 - 40
Friday Night SW 30 - 40
Saturday Morning S 20 - 30
Saturday Afternoon SSW 15 - 25
Saturday Night SSW 10 - 20
Mt. Rainier Elevation
Friday Afternoon --- -
Friday Night --- -
Saturday Morning --- -
Saturday Afternoon --- -
Saturday Night --- -
Mt. Hood Elevation
Friday Afternoon SW 30 - 40
Friday Night SW 25 - 35
Saturday Morning SSW 15 - 25
Saturday Afternoon SSW 20 - 30
Saturday Night SSW 20 - 30
Hurricane Ridge Direction - Speed
Friday Afternoon SW 20 - 30
Friday Night SW 20 - 30
Saturday Morning SW 10 - 20
Saturday Afternoon SSW 5 - 15
Saturday Night W 0 - 10
Mt. Baker Direction - Speed
Friday Afternoon S 25 - 35
Friday Night SW 20 - 30
Saturday Morning S 10 - 20
Saturday Afternoon SSW 10 - 20
Saturday Night VAR 0 - 10
Stevens and Snoqualmie Pass Direction - Speed
Friday Afternoon SW 30 - 40
Friday Night SW 30 - 40
Saturday Morning S 20 - 30
Saturday Afternoon SSW 15 - 25
Saturday Night SSW 10 - 20
Mt. Rainier Direction - Speed
Friday Afternoon --- -
Friday Night --- -
Saturday Morning --- -
Saturday Afternoon --- -
Saturday Night --- -
Mt. Hood Direction - Speed
Friday Afternoon SW 30 - 40
Friday Night SW 25 - 35
Saturday Morning SSW 15 - 25
Saturday Afternoon SSW 20 - 30
Saturday Night SSW 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
Friday Afternoon SW 40 - 60 SW 45 - 65 WSW 45 - 65 --- - WSW 40 - 60
Friday Night SW 35 - 45 SW 40 - 60 SW 35 - 50 --- - WSW 40 - 60
Saturday Morning SW 30 - 40 SW 20 - 30 SW 40 - 60 --- - SW 20 - 30
Saturday Afternoon SSW 15 - 25 SSW 15 - 25 SW 35 - 50 --- - SW 40 - 60
Mt. Baker Direction - Speed
Friday Afternoon SW 40 - 60
Friday Night SW 35 - 45
Saturday Morning SW 30 - 40
Saturday Afternoon SSW 15 - 25
Saturday Night SW 15 - 25
Washington Pass Direction - Speed
Friday Afternoon SW 45 - 65
Friday Night SW 40 - 60
Saturday Morning SW 20 - 30
Saturday Afternoon SSW 15 - 25
Saturday Night SW 20 - 30
Stevens and Snoqualmie Pass Direction - Speed
Friday Afternoon WSW 45 - 65
Friday Night SW 35 - 50
Saturday Morning SW 40 - 60
Saturday Afternoon SW 35 - 50
Saturday Night SW 25 - 35
Mt. Rainier Direction - Speed
Friday Afternoon --- -
Friday Night --- -
Saturday Morning --- -
Saturday Afternoon --- -
Saturday Night --- -
Mt. Hood Direction - Speed
Friday Afternoon WSW 40 - 60
Friday Night WSW 40 - 60
Saturday Morning SW 20 - 30
Saturday Afternoon SW 40 - 60
Saturday Night SW 35 - 50

Extended Weather Synopsis for Friday night through Friday

On Sunday a cool upper trough moving toward the Pacific Northwest near-shore waters will bring cooling and instability showers. The trough will move east and linger through Monday, bringing the heaviest shower activity on Sunday afternoon and Monday afternoon to the mountains.

Monday night the trough shifts east and a "dirty ridge" will bring a moist westerly flow and continued shower activity to the mountains through Tuesday as ridging gradually builds and attempts to push the shower activity northward.

Extended Weather

Olympics, Washington Cascades and Mt. Hood Area
Sunday Cooler than average. Instability showers. Heaviest during the afternoon. Generally light winds. Monday Cooler than average. Instability showers. Heaviest during the afternoon. Generally light winds. Tuesday Light showers in the mountains. Light W-NW flow.

Extended Snow/Freezing Levels

Mt. Baker Snoqualmie Pass Mt. Hood Easterly Flow *
Sunday Snow Level 2500' - 3500' 2500' - 3500' 3500' - 4500'
Sunday Night Snow Level 2000' - 3500' 2500' - 4500' 1500' - 3000'
Monday Snow Level 2000' - 3000' 2500' - 3500' 2500' - 3500'
Monday Night Snow Level 2000' - 3000' 1500' - 2500' 1500' - 3500'
Mt. Baker Elevation
Sunday Snow Level
2500' - 3500'
Sunday Night Snow Level
2000' - 3500'
Monday Snow Level
2000' - 3000'
Monday Night Snow Level
2000' - 3000'
Tuesday Snow Level
2000' - 3000'
Snoqualmie Pass Elevation
Sunday Snow Level
2500' - 3500'
Sunday Night Snow Level
2500' - 4500'
Monday Snow Level
2500' - 3500'
Monday Night Snow Level
1500' - 2500'
Tuesday Snow Level
2500' - 3500'
Mt. Hood Elevation
Sunday Snow Level
3500' - 4500'
Sunday Night Snow Level
1500' - 3000'
Monday Snow Level
2500' - 3500'
Monday Night Snow Level
1500' - 3500'
Tuesday Snow Level
3000' - 4000'

* 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 Apr 13, 2018

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