Issued: 9:13 PM PST Friday, November 23, 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 night through Sunday

A closed low sitting over Northwest Washington Friday afternoon will continue to bring snow showers to the region as a moist, unstable airmass continues to move through the associated trough. The flow is weak near the low over Washington State and is expected to remain weak through Friday night, with slightly stronger flow away from the low center over northern Oregon.

Snow shower activity will decrease Saturday night in the North Cascades, but further south, significant snow accumulations will continue with locally intense convective showers along the west slopes of the Cascades from the central Washington Cascades southward to Mt. Hood. A Puget Sound Convergence zone before midnight and a Vancouver Island Convergence zone after midnight, as the flow switches more Northwesterly, are likely to bring enhanced precipitation to the Central Cascades.

On Saturday, skies will start clearing early in the day. Expect a mix of clouds and sun along with noticeable afternoon warming as the instability gives way to a ridge building in along the coast. 

Saturday night should be mostly clear and fair with high clouds ahead of a weakening frontal system that will approach but not reach our coastline. Freezing levels will continue to rise.

Sunday will feature high cloud cover and significant warming in many areas as flow turns southwesterly ahead of a strong frontal system arriving on Monday.

Weather Forecast

Hurricane Ridge
Friday Night Lingering light snow showers ending early, then partially clearing.
Mt. Baker
Friday Night Light snow showers, tapering after midnight.
Stevens and Snoqualmie Pass
Friday Night Moderate snow showers, heaviest in convergence.
Mt. Rainier and Crystal
Friday Night Decreasing light to moderate convective snow showers with a chance of graupel.
Washington Pass and Leavenworth
Friday Night Light snow showers, becoming flurries after midnight.
Mt. Hood
Friday Night Decreasing moderate convective snow showers with a chance of graupel.

Snow/Freezing Level (ft)

Hurricane Ridge Mt. Baker Washington Pass Leavenworth Stevens Pass Snoqualmie Pass Mt. Rainier, Crystal & White Pass Mt. Hood
Friday Evening Snow Level 2500' 2500' 2000' 2500' 2500' 2500' 2500' 2500'
Friday Night Snow Level 2500' 1500' 2000' 2500' 2500' 2500' 2500' 2500'
Saturday Morning Snow Level 3000' 1500' 2000' 2500' 2500' 2500' 3000' 2500'
Saturday Afternoon Freezing Level 4500' 3000' 3000' 5000' 4000' 4500' 4500' 5000'
Saturday Evening Freezing Level 4500' 2500' 3000' 4000' 3500' 3500' 4500' 4500'
Saturday Night Freezing Level * 6000' 4000' 4000' 3500' 3000' 3000' 5000' 8000'
Sunday Morning Freezing Level * 7500' 6000' 3500' 3500' 6500' 7500' 8000' 8500'
Hurricane Ridge Elevation
Friday Evening Snow Level
2500'
Friday Night Snow Level
2500'
Saturday Morning Snow Level
3000'
Saturday Afternoon Freezing Level
4500'
Saturday Evening Freezing Level
4500'
Saturday Night Freezing Level
6000'
(Easterly Flow *)
Sunday Morning Freezing Level
7500'
(Easterly Flow *)
Sunday Afternoon Freezing Level
8500'
(Easterly Flow *)
Mt. Baker Elevation
Friday Evening Snow Level
2500'
Friday Night Snow Level
1500'
Saturday Morning Snow Level
1500'
Saturday Afternoon Freezing Level
3000'
Saturday Evening Freezing Level
2500'
Saturday Night Freezing Level
4000'
(Easterly Flow *)
Sunday Morning Freezing Level
6000'
(Easterly Flow *)
Sunday Afternoon Freezing Level
7500'
(Easterly Flow *)
Washington Pass Elevation
Friday Evening Snow Level
2000'
Friday Night Snow Level
2000'
Saturday Morning Snow Level
2000'
Saturday Afternoon Freezing Level
3000'
Saturday Evening Freezing Level
3000'
Saturday Night Freezing Level
4000'
(Easterly Flow *)
Sunday Morning Freezing Level
3500'
(Easterly Flow *)
Sunday Afternoon Freezing Level
3500'
(Easterly Flow *)
Leavenworth Elevation
Friday Evening Snow Level
2500'
Friday Night Snow Level
2500'
Saturday Morning Snow Level
2500'
Saturday Afternoon Freezing Level
5000'
Saturday Evening Freezing Level
4000'
Saturday Night Freezing Level
3500'
(Easterly Flow *)
Sunday Morning Freezing Level
3500'
(Easterly Flow *)
Sunday Afternoon Freezing Level
8000'
(Easterly Flow *)
Stevens Pass Elevation
Friday Evening Snow Level
2500'
Friday Night Snow Level
2500'
Saturday Morning Snow Level
2500'
Saturday Afternoon Freezing Level
4000'
Saturday Evening Freezing Level
3500'
Saturday Night Freezing Level
3000'
(Easterly Flow *)
Sunday Morning Freezing Level
6500'
(Easterly Flow *)
Sunday Afternoon Freezing Level
8000'
(Easterly Flow *)
Snoqualmie Pass Elevation
Friday Evening Snow Level
2500'
Friday Night Snow Level
2500'
Saturday Morning Snow Level
2500'
Saturday Afternoon Freezing Level
4500'
Saturday Evening Freezing Level
3500'
Saturday Night Freezing Level
3000'
(Easterly Flow *)
Sunday Morning Freezing Level
7500'
(Easterly Flow *)
Sunday Afternoon Freezing Level
8000'
(Easterly Flow *)
Mt. Rainier & Crystal Elevation
Friday Evening Snow Level
2500'
Friday Night Snow Level
2500'
Saturday Morning Snow Level
3000'
Saturday Afternoon Freezing Level
4500'
Saturday Evening Freezing Level
4500'
Saturday Night Freezing Level
5000'
(Easterly Flow *)
Sunday Morning Freezing Level
8000'
(Easterly Flow *)
Sunday Afternoon Freezing Level
8500'
(Easterly Flow *)
Mt. Hood Elevation
Friday Evening Snow Level
2500'
Friday Night Snow Level
2500'
Saturday Morning Snow Level
2500'
Saturday Afternoon Freezing Level
5000'
Saturday Evening Freezing Level
4500'
Saturday Night Freezing Level
8000'
(Easterly Flow *)
Sunday Morning Freezing Level
8500'
(Easterly Flow *)
Sunday Afternoon Freezing Level
9000'
(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

Friday Night Sunday Sunday Night Sunday
4 pm - 4 am 4 am - 4 pm 4 pm - 4 am 4 am - 4 pm
Hurricane Ridge LT 0.10 0 0 0
Mt Baker Ski Area LT 0.10 0 0 0
Washington Pass LT 0.10 0 0 0
Stevens Pass 0.25 - 0.50 0 0 0
Snoqualmie Pass 0.50 LT 0.10 0 0
Leavenworth 0 0 0 0
Mission Ridge 0 0 0 0
Crystal Mt LT 0.25 0 0 0
Paradise 0.25 0 0 0
White Pass LT 0.25 0 0 0
Mt Hood Meadows 0.75 LT 0.10 0 0
0.75 -1.00 LT 0.10 0 0
Hurricane Ridge Precipitation Forecast
Friday Night LT 0.10
Sunday 0
Sunday Night 0
Sunday 0
Mt Baker Ski Area Precipitation Forecast
Friday Night LT 0.10
Sunday 0
Sunday Night 0
Sunday 0
Washington Pass Precipitation Forecast
Friday Night LT 0.10
Sunday 0
Sunday Night 0
Sunday 0
Stevens Pass Precipitation Forecast
Friday Night 0.25 - 0.50
Sunday 0
Sunday Night 0
Sunday 0
Snoqualmie Pass Precipitation Forecast
Friday Night 0.50
Sunday LT 0.10
Sunday Night 0
Sunday 0
Leavenworth Precipitation Forecast
Friday Night 0
Sunday 0
Sunday Night 0
Sunday 0
Mission Ridge Precipitation Forecast
Friday Night 0
Sunday 0
Sunday Night 0
Sunday 0
Crystal Mt Precipitation Forecast
Friday Night LT 0.25
Sunday 0
Sunday Night 0
Sunday 0
Paradise Precipitation Forecast
Friday Night 0.25
Sunday 0
Sunday Night 0
Sunday 0
White Pass Precipitation Forecast
Friday Night LT 0.25
Sunday 0
Sunday Night 0
Sunday 0
Mt Hood Meadows Precipitation Forecast
Friday Night 0.75
Sunday LT 0.10
Sunday Night 0
Sunday 0
Timberline Precipitation Forecast
Friday Night 0.75 -1.00
Sunday LT 0.10
Sunday Night 0
Sunday 0

Free Winds at 5000' (mph)

Hurricane Ridge Mt. Baker Stevens to Snoqualmie Pass Mt. Rainier Mt. Hood
Friday Evening W 10 - 20 WSW 10 - 20 W 10 - 20 W 5 - 15 W 15 - 25
Friday Night NW 10 - 20 NW 5 - 15 WNW 10 - 20 WNW 10 - 20 WNW 20 - 30
Saturday Morning WNW 10 - 20 WSW 5 - 15 NW 15 - 25 W 5 - 15 WNW 15 - 25
Hurricane Ridge Elevation
Friday Evening W 10 - 20
Friday Night NW 10 - 20
Saturday Morning WNW 10 - 20
Saturday Afternoon SW 5 - 15
Mt. Baker Elevation
Friday Evening WSW 10 - 20
Friday Night NW 5 - 15
Saturday Morning WSW 5 - 15
Saturday Afternoon SW 5 - 15
Stevens and Snoqualmie Pass Elevation
Friday Evening W 10 - 20
Friday Night WNW 10 - 20
Saturday Morning NW 15 - 25
Saturday Afternoon W 5 - 15
Mt. Rainier Elevation
Friday Evening W 5 - 15
Friday Night WNW 10 - 20
Saturday Morning W 5 - 15
Saturday Afternoon W 5 - 15
Mt. Hood Elevation
Friday Evening W 15 - 25
Friday Night WNW 20 - 30
Saturday Morning WNW 15 - 25
Saturday Afternoon VAR 0 - 10
Hurricane Ridge Direction - Speed
Friday Evening W 10 - 20
Friday Night NW 10 - 20
Saturday Morning WNW 10 - 20
Saturday Afternoon SW 5 - 15
Mt. Baker Direction - Speed
Friday Evening WSW 10 - 20
Friday Night NW 5 - 15
Saturday Morning WSW 5 - 15
Saturday Afternoon SW 5 - 15
Stevens and Snoqualmie Pass Direction - Speed
Friday Evening W 10 - 20
Friday Night WNW 10 - 20
Saturday Morning NW 15 - 25
Saturday Afternoon W 5 - 15
Mt. Rainier Direction - Speed
Friday Evening W 5 - 15
Friday Night WNW 10 - 20
Saturday Morning W 5 - 15
Saturday Afternoon W 5 - 15
Mt. Hood Direction - Speed
Friday Evening W 15 - 25
Friday Night WNW 20 - 30
Saturday Morning WNW 15 - 25
Saturday Afternoon VAR 0 - 10

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 Evening NW 15 - 25 NW 20 - 30 NW 20 - 30 WSW 30 - 45 WNW 35 - 50
Friday Night NNW 15 - 25 N 15 - 25 NNW 25 - 35 NNW 25 - 35 NW 35 - 50
Saturday Morning WNW 10 - 20 NW 10 - 20 NW 10 - 20 NNW 10 - 20 NNW 10 - 20
Mt. Baker Direction - Speed
Friday Evening NW 15 - 25
Friday Night NNW 15 - 25
Saturday Morning WNW 10 - 20
Saturday Afternoon WSW 15 - 25
Washington Pass Direction - Speed
Friday Evening NW 20 - 30
Friday Night N 15 - 25
Saturday Morning NW 10 - 20
Saturday Afternoon W 15 - 25
Stevens and Snoqualmie Pass Direction - Speed
Friday Evening NW 20 - 30
Friday Night NNW 25 - 35
Saturday Morning NW 10 - 20
Saturday Afternoon WNW 10 - 20
Mt. Rainier Direction - Speed
Friday Evening WSW 30 - 45
Friday Night NNW 25 - 35
Saturday Morning NNW 10 - 20
Saturday Afternoon NW 5 - 15
Mt. Hood Direction - Speed
Friday Evening WNW 35 - 50
Friday Night NW 35 - 50
Saturday Morning NNW 10 - 20
Saturday Afternoon NNW 10 - 20

Extended Weather Synopsis for Sunday night through Sunday

Sunday night the first precipitation will arrive on our coastline ahead of a strong front, tapping into subtropical moisture ahead of a broad and deep low/trough combo over the northern Pacific. 

This storm system will bring high snow levels and 1-4" of precipitation for most of the west slopes of the Cascades with .5-2.5" anticipated along the east slopes of the Cascades for Monday and Tuesday. Moderate to strong S-SW flow will scour out most of the cold air pools east of the Cascade Crest. 

The cold front is expected to pass Tuesday morning, bringing a switch to W-SW flow and gradually lowering snow levels during the day Tuesday along and gradually decreasing precipitation. Snow levels should remain above pass levels in most areas as the trough axis remains well (1000 miles) offshore, around 145W, keeping the coldest air offshore.

Extended Snow/Freezing Levels

Mt. Baker Snoqualmie Pass Mt. Hood Easterly Flow *
Sunday Night Snow Level 6500' - 7500' 5500' - 7500' 7000' - 8000' *
Monday Snow Level 7000' - 8000' 7000' - 8000' 8000' - 9000' *
Monday Night Snow Level 6000' - 7000' 6000' - 7500' 7000' - 8000' *
Mt. Baker Elevation
Sunday Night Snow Level
6500' - 7500'
(Easterly Flow *)
Monday Snow Level
7000' - 8000'
(Easterly Flow *)
Monday Night Snow Level
6000' - 7000'
(Easterly Flow *)
Tuesday Snow Level
4500' - 5500'
(Easterly Flow *)
Snoqualmie Pass Elevation
Sunday Night Snow Level
5500' - 7500'
(Easterly Flow *)
Monday Snow Level
7000' - 8000'
(Easterly Flow *)
Monday Night Snow Level
6000' - 7500'
(Easterly Flow *)
Tuesday Snow Level
4500' - 5500'
(Easterly Flow *)
Mt. Hood Elevation
Sunday Night Snow Level
7000' - 8000'
(Easterly Flow *)
Monday Snow Level
8000' - 9000'
(Easterly Flow *)
Monday Night Snow Level
7000' - 8000'
(Easterly Flow *)
Tuesday Snow Level
5500' - 6500'
(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.

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

Previous forecast from Nov 22, 2018

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