Issued: 7:43 AM PDT Friday, March 24, 2017
by Garth Ferber

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

Weather Synopsis for Friday & Thursday

The late winter weather continues in the Olympics and Cascades.

Increasing southwest flow aloft began to carry a front into the Northwest on Thursday night. NWAC stations along the Cascade west slopes above the Pass levels had 5-9 inches of snow by 5 am Friday morning.

Radar indicates the somewhat slow moving front has crossed the Olympics and it will continue across the Cascades Friday morning causing moderate to occasional heavy rain or snow which which should be generally heavier on the volcanoes.

Yesterday afternoon's UW WRF run indicates a temporary decrease in showers following the front Friday midday.

An upper trough and slightly unstable airmass should move across the Northwest Friday afternoon to Saturday morning. This should cause renewed showers Friday afternoon which should continue to be a bit heavier on the volcanoes. Yesterday afternoon's UW WRF run indicates that convergence will generally stay up around the Glacier Peak area.

A weak shortwave ridge should move over the Northwest and minor surface high pressure should build north over the area Saturday afternoon and night.

Weather Forecast

Olympics
Friday Morning

Light to moderate showers. Moderate alpine winds.

Friday Mid-day

Light to moderate showers. Moderate alpine winds.

Friday Afternoon

Renewed moderate occasional heavy showers. Moderate alpine winds.

Friday Night - Saturday Morning

Decreasing light showers.

Washington Cascades near and west of the crest including Stevens, Snoqualmie, and White Passes
Friday Morning

Moderate occasional heavy rain or snow generally heaviest on the volcanoes. Moderate alpine winds.

Friday Mid-day

Light to moderate showers. Moderate alpine winds.

Friday Afternoon

Renewed moderate occasional heavy showers generally heaviest on the volcanoes. Moderate alpine winds.

Friday Night - Saturday Morning

Decreasing light showers.

East slopes of the Washington Cascades
Friday Morning

Moderate rain or snow. Moderate alpine winds.

Friday Mid-day

Light showers. Moderate alpine winds.

Friday Afternoon

Renewed light to moderate showers. Moderate alpine winds.

Friday Night - Saturday Morning

Decreasing light showers heaviest higher elevations.

Mt. Hood Area
Friday Morning

Moderate occasional heavy rain or snow. Moderate alpine winds.

Friday Mid-day

Light to moderate showers. Moderate alpine winds.

Friday Afternoon

Renewed moderate occasional heavy showers. Moderate alpine winds.

Friday Night - Saturday Morning

Decreasing light showers.

Snow/Freezing Level (ft)

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

* 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

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

Free Winds at 5000' (mph)

Hurricane Ridge Mt. Baker Stevens to Snoqualmie Pass Mt. Rainier Mt. Hood
Friday Morning - Friday Afternoon SSW 20 - 30 SSW 25 - 35 SSW 20 - 30 --- - SSW 20 - 30
Friday Night SW 20 - 30 SW 20 - 30 SW 20 - 30 --- - SW 25 - 35
Saturday Morning SW 15 - 25 SW 15 - 25 SW 15 - 25 --- - SW 15 - 25
Saturday Afternoon WSW 10 - 20 WSW 10 - 20 WSW 15 - 25 --- - WSW 15 - 25
Hurricane Ridge Elevation
Friday Morning - Friday Afternoon SSW 20 - 30
Friday Night SW 20 - 30
Saturday Morning SW 15 - 25
Saturday Afternoon WSW 10 - 20
Saturday Night WSW 15 - 25
Mt. Baker Elevation
Friday Morning - Friday Afternoon SSW 25 - 35
Friday Night SW 20 - 30
Saturday Morning SW 15 - 25
Saturday Afternoon WSW 10 - 20
Saturday Night WSW 10 - 20
Stevens and Snoqualmie Pass Elevation
Friday Morning - Friday Afternoon SSW 20 - 30
Friday Night SW 20 - 30
Saturday Morning SW 15 - 25
Saturday Afternoon WSW 15 - 25
Saturday Night WSW 10 - 20
Mt. Rainier Elevation
Friday Morning - Friday Afternoon --- -
Friday Night --- -
Saturday Morning --- -
Saturday Afternoon --- -
Saturday Night --- -
Mt. Hood Elevation
Friday Morning - Friday Afternoon SSW 20 - 30
Friday Night SW 25 - 35
Saturday Morning SW 15 - 25
Saturday Afternoon WSW 15 - 25
Saturday Night WSW 10 - 20
Hurricane Ridge Direction - Speed
Friday Morning - Friday Afternoon SSW 20 - 30
Friday Night SW 20 - 30
Saturday Morning SW 15 - 25
Saturday Afternoon WSW 10 - 20
Saturday Night WSW 15 - 25
Mt. Baker Direction - Speed
Friday Morning - Friday Afternoon SSW 25 - 35
Friday Night SW 20 - 30
Saturday Morning SW 15 - 25
Saturday Afternoon WSW 10 - 20
Saturday Night WSW 10 - 20
Stevens and Snoqualmie Pass Direction - Speed
Friday Morning - Friday Afternoon SSW 20 - 30
Friday Night SW 20 - 30
Saturday Morning SW 15 - 25
Saturday Afternoon WSW 15 - 25
Saturday Night WSW 10 - 20
Mt. Rainier Direction - Speed
Friday Morning - Friday Afternoon --- -
Friday Night --- -
Saturday Morning --- -
Saturday Afternoon --- -
Saturday Night --- -
Mt. Hood Direction - Speed
Friday Morning - Friday Afternoon SSW 20 - 30
Friday Night SW 25 - 35
Saturday Morning SW 15 - 25
Saturday Afternoon WSW 15 - 25
Saturday Night WSW 10 - 20

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 Morning - Friday Afternoon SW 35 - 50 SW 30 - 45 SW 30 - 45 --- - SW 40 - 60
Friday Night SW 25 - 35 SW 25 - 35 SW 25 - 35 --- - SW 35 - 50
Saturday Morning WSW 25 - 35 WSW 20 - 30 WSW 25 - 35 --- - WSW 20 - 30
Saturday Afternoon WSW 20 - 30 WSW 20 - 30 WSW 25 - 35 --- - WSW 20 - 30
Mt. Baker Direction - Speed
Friday Morning - Friday Afternoon SW 35 - 50
Friday Night SW 25 - 35
Saturday Morning WSW 25 - 35
Saturday Afternoon WSW 20 - 30
Saturday Night SSW 15 - 25
Washington Pass Direction - Speed
Friday Morning - Friday Afternoon SW 30 - 45
Friday Night SW 25 - 35
Saturday Morning WSW 20 - 30
Saturday Afternoon WSW 20 - 30
Saturday Night SSW 10 - 20
Stevens and Snoqualmie Pass Direction - Speed
Friday Morning - Friday Afternoon SW 30 - 45
Friday Night SW 25 - 35
Saturday Morning WSW 25 - 35
Saturday Afternoon WSW 25 - 35
Saturday Night SSW 15 - 25
Mt. Rainier Direction - Speed
Friday Morning - Friday Afternoon --- -
Friday Night --- -
Saturday Morning --- -
Saturday Afternoon --- -
Saturday Night --- -
Mt. Hood Direction - Speed
Friday Morning - Friday Afternoon SW 40 - 60
Friday Night SW 35 - 50
Saturday Morning WSW 20 - 30
Saturday Afternoon WSW 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.

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

Previous forecast from Mar 24, 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.

Synopsis corrections at 745 am.