Issued: 1:44 PM PST Sunday, February 19, 2017
by Garth Ferber

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

Weather Synopsis for Sunday & Friday

Some snow returned to the Olympics and Cascades on Saturday and by Sunday morning NWAC stations along the Cascade west slopes had 2-6 inches, with probably about 1-3 inches along the Cascade east slopes and about 5-6 inches at Mt Hood.

A fairly large weak upper trough will linger over the northeast Pacific Ocean through early next week with the main flow generally to Oregon and California. This will bring some more snow to to the Olympics and Cascades with a gradual lowering of snow levels!

A weakening low pressure system will move past Cape Flattery and to Vancouver Island on Sunday with a front moving across the Northwest. A slight increase in alpine winds should be seen in the Olympics and Cascades. Radar Sunday afternoon shows more bands of precipitation will move across the area.

A decrease in winds and snow showers should be seen in the Olympics and Cascades as the low and front moves off to the east on Sunday night.

Another weakening low pressure system will move past Astoria on Monday with another front moving mainly across the south Cascades. This should cause an increase in alpine winds mainly in the south Cascades.  Snow should increase again on Monday especially in the south Cascades. The south Cascades will be windier and snowier compared to the Olympics and north Cascades on Monday.

Another decrease in winds and snow showers should be seen in the Olympics and Cascades as the second low and front moves off to the east on Monday night.

Weather Forecast

Olympics
Sunday Afternoon

Further slightly increasing alpine winds. Further increasing light snow showers.

Sunday Night

Decreasing alpine winds. Decreasing light snow showers.

Monday

Increasing light snow.

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

Further slightly increasing alpine winds. Further increasing light snow showers becoming light to moderate on the volcanoes.

Sunday Night

Decreasing alpine winds. Decreasing light snow showers.

Monday

Increasing alpine winds mainly south part. Increasing light to moderate snow north to central part and Passes, increasing moderate occasional heavy snow south volcanoes.

East slopes of the Washington Cascades
Sunday Afternoon

Further slightly increasing alpine winds. Further increasing light snow. showers.

Sunday Night

Decreasing alpine winds. Decreasing light snow showers heaviest higher elevations.

Monday

Increasing alpine winds mainly south part. Increasing light to moderate snow.

Mt. Hood Area
Sunday Afternoon

Further slightly increasing alpine winds. Further increasing light to moderate snow showers.

Sunday Night

Decreasing alpine winds. Decreasing light snow showers.

Monday

Increasing alpine winds. Increasing moderate occasional heavy snow.

Snow/Freezing Level (ft)

Hurricane Ridge Mt. Baker Washington Pass Leavenworth Stevens Pass Snoqualmie Pass Mt. Rainier, Crystal & White Pass Mt. Hood
Sunday Afternoon Snow Level * 3000' 3000' 3000' ' ' 3000' ' 3500'
Sunday Night - Monday Morning Snow Level 2500' 2500' 2000' ' ' 2500' ' 3500'
Monday Afternoon Snow Level * 3000' 3000' 3000' ' ' 3000' ' 4000'
Hurricane Ridge Elevation
Sunday Afternoon Snow Level
3000'
(Easterly Flow *)
Sunday Night - Monday Morning Snow Level
2500'
Monday Afternoon Snow Level
3000'
(Easterly Flow *)
Monday Night Snow Level
2000'
Mt. Baker Elevation
Sunday Afternoon Snow Level
3000'
(Easterly Flow *)
Sunday Night - Monday Morning Snow Level
2500'
Monday Afternoon Snow Level
3000'
(Easterly Flow *)
Monday Night Snow Level
2000'
Washington Pass Elevation
Sunday Afternoon Snow Level
3000'
(Easterly Flow *)
Sunday Night - Monday Morning Snow Level
2000'
Monday Afternoon Snow Level
3000'
(Easterly Flow *)
Monday Night Snow Level
2000'
Leavenworth Elevation
Sunday Afternoon Snow Level
'
(Easterly Flow *)
Sunday Night - Monday Morning Snow Level
'
Monday Afternoon Snow Level
'
(Easterly Flow *)
Monday Night Snow Level
'
Stevens Pass Elevation
Sunday Afternoon Snow Level
'
(Easterly Flow *)
Sunday Night - Monday Morning Snow Level
'
Monday Afternoon Snow Level
'
(Easterly Flow *)
Monday Night Snow Level
'
Snoqualmie Pass Elevation
Sunday Afternoon Snow Level
3000'
(Easterly Flow *)
Sunday Night - Monday Morning Snow Level
2500'
Monday Afternoon Snow Level
3000'
(Easterly Flow *)
Monday Night Snow Level
2500'
Mt. Rainier & Crystal Elevation
Sunday Afternoon Snow Level
'
(Easterly Flow *)
Sunday Night - Monday Morning Snow Level
'
Monday Afternoon Snow Level
'
(Easterly Flow *)
Monday Night Snow Level
'
Mt. Hood Elevation
Sunday Afternoon Snow Level
3500'
(Easterly Flow *)
Sunday Night - Monday Morning Snow Level
3500'
Monday Afternoon Snow Level
4000'
(Easterly Flow *)
Monday Night Snow Level
3000'

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

Free Winds at 5000' (mph)

Hurricane Ridge Mt. Baker Stevens to Snoqualmie Pass Mt. Rainier Mt. Hood
Sunday Afternoon SSW 20 - 30 SSW 25 - 35 SSW 20 - 30 --- - SW 25 - 35
Sunday Night SSE 10 - 20 SSE 10 - 20 SSE 10 - 20 --- - SSE 10 - 20
Monday Morning SSE 15 - 25 SSE 5 - 15 SSE 20 - 30 --- - SSW 25 - 35
Monday Afternoon NW 5 - 15 NE 5 - 15 SSE 20 - 30 --- - SW 30 - 45
Hurricane Ridge Elevation
Sunday Afternoon SSW 20 - 30
Sunday Night SSE 10 - 20
Monday Morning SSE 15 - 25
Monday Afternoon NW 5 - 15
Monday Night NW 10 - 20
Mt. Baker Elevation
Sunday Afternoon SSW 25 - 35
Sunday Night SSE 10 - 20
Monday Morning SSE 5 - 15
Monday Afternoon NE 5 - 15
Monday Night NW 5 - 15
Stevens and Snoqualmie Pass Elevation
Sunday Afternoon SSW 20 - 30
Sunday Night SSE 10 - 20
Monday Morning SSE 20 - 30
Monday Afternoon SSE 20 - 30
Monday Night VAR 0 - 10
Mt. Rainier Elevation
Sunday Afternoon --- -
Sunday Night --- -
Monday Morning --- -
Monday Afternoon --- -
Monday Night --- -
Mt. Hood Elevation
Sunday Afternoon SW 25 - 35
Sunday Night SSE 10 - 20
Monday Morning SSW 25 - 35
Monday Afternoon SW 30 - 45
Monday Night SSE 10 - 20
Hurricane Ridge Direction - Speed
Sunday Afternoon SSW 20 - 30
Sunday Night SSE 10 - 20
Monday Morning SSE 15 - 25
Monday Afternoon NW 5 - 15
Monday Night NW 10 - 20
Mt. Baker Direction - Speed
Sunday Afternoon SSW 25 - 35
Sunday Night SSE 10 - 20
Monday Morning SSE 5 - 15
Monday Afternoon NE 5 - 15
Monday Night NW 5 - 15
Stevens and Snoqualmie Pass Direction - Speed
Sunday Afternoon SSW 20 - 30
Sunday Night SSE 10 - 20
Monday Morning SSE 20 - 30
Monday Afternoon SSE 20 - 30
Monday Night VAR 0 - 10
Mt. Rainier Direction - Speed
Sunday Afternoon --- -
Sunday Night --- -
Monday Morning --- -
Monday Afternoon --- -
Monday Night --- -
Mt. Hood Direction - Speed
Sunday Afternoon SW 25 - 35
Sunday Night SSE 10 - 20
Monday Morning SSW 25 - 35
Monday Afternoon SW 30 - 45
Monday Night SSE 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
Sunday Afternoon SW 30 - 45 SW 25 - 35 SW 30 - 45 --- - SW 35 - 50
Sunday Night SSW 10 - 20 SSW 15 - 25 SSW 15 - 25 --- - SSW 30 - 45
Monday Morning SSE 15 - 25 SSE 30 - 45 SSW 40 - 60 --- - SSW 60 - 80
Monday Afternoon SW 25 - 35 SW 30 - 45 SW 50 - 70 --- - SW 60 - 80
Mt. Baker Direction - Speed
Sunday Afternoon SW 30 - 45
Sunday Night SSW 10 - 20
Monday Morning SSE 15 - 25
Monday Afternoon SW 25 - 35
Monday Night VAR 0 - 10
Washington Pass Direction - Speed
Sunday Afternoon SW 25 - 35
Sunday Night SSW 15 - 25
Monday Morning SSE 30 - 45
Monday Afternoon SW 30 - 45
Monday Night SSW 5 - 15
Stevens and Snoqualmie Pass Direction - Speed
Sunday Afternoon SW 30 - 45
Sunday Night SSW 15 - 25
Monday Morning SSW 40 - 60
Monday Afternoon SW 50 - 70
Monday Night VAR 0 - 10
Mt. Rainier Direction - Speed
Sunday Afternoon --- -
Sunday Night --- -
Monday Morning --- -
Monday Afternoon --- -
Monday Night --- -
Mt. Hood Direction - Speed
Sunday Afternoon SW 35 - 50
Sunday Night SSW 30 - 45
Monday Morning SSW 60 - 80
Monday Afternoon SW 60 - 80
Monday Night SW 40 - 60

Extended Weather Synopsis for Friday night through Friday

Yet another weakening low pressure system should across Oregon on Tuesday with the main flow over California. Winds and moisture from the low should affect mainly the south Cascades.

The large weak upper trough should shift to over the US west coast on Wednesday with the main part of the trough moving to California. This should cause a change to a cool weak west flow over the Northwest.

The large weak upper trough should linger over the west US on Thursday. This should cause weak flow with a cool air mass over the Northwest.

Extended Weather

Olympics, Washington Cascades, Mt Hood
Tuesday - Tuesday

Light snow Olympics and north Cascades, light to moderate snow central Cascades and moderate to heavy snow south Cascades. Cooler.

Wednesday

Mostly light snow showers heaviest along the west slopes of the Cascades. Cooler.

Thursday

Light snow showers mainly along the west slopes of the Cascades. Cooler.

Extended Snow/Freezing Levels

Mt. Baker Snoqualmie Pass Mt. Hood Easterly Flow *
Tuesday Snow Level 2000' - 3000' 200' - 3000' 2000' - 3000'
Wednesday Snow Level 1000' - 2000' 1000' - 2000' 1000' - 2000'
Mt. Baker Elevation
Tuesday Snow Level
2000' - 3000'
Wednesday Snow Level
1000' - 2000'
Thursday Snow Level
500' - 1500'
Snoqualmie Pass Elevation
Tuesday Snow Level
200' - 3000'
Wednesday Snow Level
1000' - 2000'
Thursday Snow Level
500' - 1500'
Mt. Hood Elevation
Tuesday Snow Level
2000' - 3000'
Wednesday Snow Level
1000' - 2000'
Thursday Snow Level
500' - 1500'

* 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 Feb 19, 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.