Issued: 2:50 PM PST Monday, December 17, 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 Monday night through Wednesday

On the heels of the previous system, a strong jet aimed at northern Oregon will bring a slow-moving major storm system into the Pacific Northwest, impacting all mountain regions with significant rain or snow and strong winds over the next 36 hours while the parent low temporarily stalls in the Gulf of Alaska.

Monday night, a warm front will pass through the region bringing heavy rain and high elevation snow along with increasing winds to many locations. Very stormy weather will continue during the day on Tuesday as the associated cold front slides E-SE during the late morning and mid-day hours. Snow levels will gradually lower as precipitation becomes post-frontal in character and winds shift from S-SW to W-SW, but remain moderate to strong. Tuesday night and Wednesday morning, cooler post-frontal rain and snow showers continue, but gradually decrease and end from south to north.

Weather Forecast

Hurricane Ridge
Monday Night Very stormy with moderate rain and high elevation snow, strong and potentially damaging winds, and rising snow levels.
Mt. Baker
Monday Night Very stormy with rain and snow increasing during the early evening and becoming moderate to heavy. Strong winds. Rising snow levels.
Washington Pass and Leavenworth
Monday Night Stormy with moderate snow; moderate winds gusting strong; gradually rising snow levels.
Stevens and Snoqualmie Pass
Monday Night Stormy with moderate to occasionally heavy snow at Snoqualmie Pass; light to moderate snow at Stevens Pass.; moderate winds gusting strong; gradually rising snow levels. Light to moderate easterly flow likely to keep Snoqualmie precipitation frozen.
Mt. Rainier, Crystal and White Pass
Monday Night Very stormy with increasing rain and snow becoming heavy for Paradise, Crystal, and White Passes. Rising snow levels. Moderate winds becoming strong after midnight.
Mt. Hood
Monday Night Very stormy with increasing moderate rain and high elevation snow; rising snow levels; strong winds.

Snow/Freezing Level (ft)

Hurricane Ridge Mt. Baker Washington Pass Leavenworth Stevens Pass Snoqualmie Pass Mt. Rainier, Crystal & White Pass Mt. Hood
Monday Evening Snow Level * 4500' 3500' 3500' 3500' 3500' 3500' 4000' 4500'
Monday Night Snow Level * 5500' 3500' 3000' 3000' 3500' 4000' 4500' 6500'
Tuesday Morning Snow Level 5000' 4000' 3500' 4500' 4000' 5000' 5500' 7000'
Tuesday Afternoon Snow Level 4000' 4000' 4000' 4500' 4000' 4500' 4500' 5000'
Tuesday Evening Snow Level 3500' 3500' 4000' 4000' 3500' 4000' 4000' 4500'
Tuesday Night Snow Level 3500' 3000' 3000' 3500' 3000' 3000' 3500' 4000'
Wednesday Morning Snow Level 3500' 3000' 3000' 3500' 3000' 3000' 3000' 3500'
Hurricane Ridge Elevation
Monday Evening Snow Level
4500'
(Easterly Flow *)
Monday Night Snow Level
5500'
(Easterly Flow *)
Tuesday Morning Snow Level
5000'
Tuesday Afternoon Snow Level
4000'
Tuesday Evening Snow Level
3500'
Tuesday Night Snow Level
3500'
Wednesday Morning Snow Level
3500'
Wednesday Afternoon Snow Level
3500'
Mt. Baker Elevation
Monday Evening Snow Level
3500'
(Easterly Flow *)
Monday Night Snow Level
3500'
(Easterly Flow *)
Tuesday Morning Snow Level
4000'
Tuesday Afternoon Snow Level
4000'
Tuesday Evening Snow Level
3500'
Tuesday Night Snow Level
3000'
Wednesday Morning Snow Level
3000'
Wednesday Afternoon Snow Level
3500'
Washington Pass Elevation
Monday Evening Snow Level
3500'
(Easterly Flow *)
Monday Night Snow Level
3000'
(Easterly Flow *)
Tuesday Morning Snow Level
3500'
Tuesday Afternoon Snow Level
4000'
Tuesday Evening Snow Level
4000'
Tuesday Night Snow Level
3000'
Wednesday Morning Snow Level
3000'
Wednesday Afternoon Snow Level
3500'
Leavenworth Elevation
Monday Evening Snow Level
3500'
(Easterly Flow *)
Monday Night Snow Level
3000'
(Easterly Flow *)
Tuesday Morning Snow Level
4500'
Tuesday Afternoon Snow Level
4500'
Tuesday Evening Snow Level
4000'
Tuesday Night Snow Level
3500'
Wednesday Morning Snow Level
3500'
Wednesday Afternoon Snow Level
3500'
Stevens Pass Elevation
Monday Evening Snow Level
3500'
(Easterly Flow *)
Monday Night Snow Level
3500'
(Easterly Flow *)
Tuesday Morning Snow Level
4000'
Tuesday Afternoon Snow Level
4000'
Tuesday Evening Snow Level
3500'
Tuesday Night Snow Level
3000'
Wednesday Morning Snow Level
3000'
Wednesday Afternoon Snow Level
3500'
Snoqualmie Pass Elevation
Monday Evening Snow Level
3500'
(Easterly Flow *)
Monday Night Snow Level
4000'
(Easterly Flow *)
Tuesday Morning Snow Level
5000'
Tuesday Afternoon Snow Level
4500'
Tuesday Evening Snow Level
4000'
Tuesday Night Snow Level
3000'
Wednesday Morning Snow Level
3000'
Wednesday Afternoon Snow Level
3500'
Mt. Rainier & Crystal Elevation
Monday Evening Snow Level
4000'
(Easterly Flow *)
Monday Night Snow Level
4500'
(Easterly Flow *)
Tuesday Morning Snow Level
5500'
Tuesday Afternoon Snow Level
4500'
Tuesday Evening Snow Level
4000'
Tuesday Night Snow Level
3500'
Wednesday Morning Snow Level
3000'
Wednesday Afternoon Snow Level
3500'
Mt. Hood Elevation
Monday Evening Snow Level
4500'
(Easterly Flow *)
Monday Night Snow Level
6500'
(Easterly Flow *)
Tuesday Morning Snow Level
7000'
Tuesday Afternoon Snow Level
5000'
Tuesday Evening Snow Level
4500'
Tuesday Night Snow Level
4000'
Wednesday Morning Snow Level
3500'
Wednesday Afternoon Snow Level
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.

Precipitation Forecast

Monday Night Wednesday Wednesday Night Wednesday
4 pm - 4 am 4 am - 4 pm 4 pm - 4 am 4 am - 4 pm
Hurricane Ridge 0.50 - 0.75 LT 0.25 0.25 LT 0.10
Mt Baker Ski Area 2.00 0.75 -1.00 0.50 0.25
Washington Pass 1.00 0.75 -1.00 0.50 - 0.75 0.25
Leavenworth 0.50 0.25 - 0.50 0.25 LT 0.10
Stevens Pass 0.50 0.50 - 0.75 0.50 0.25
Snoqualmie Pass 1.00 - 1.50 1.00 0.75 0.25
Mission Ridge 1.00 - 1.50 0.50 LT 0.25 0
Crystal Mt 1.50 - 2.00 0.75 0.25 LT 0.10
Paradise 2.00 1.50 1.00 LT 0.25
White Pass 1.00 1.00 0.75 LT 0.10
Mt Hood Meadows 1.00 1.00 - 1.50 0.75 0
1.00 1.50 0.75 0
Hurricane Ridge Precipitation Forecast
Monday Night 0.50 - 0.75
Wednesday LT 0.25
Wednesday Night 0.25
Wednesday LT 0.10
Mt Baker Ski Area Precipitation Forecast
Monday Night 2.00
Wednesday 0.75 -1.00
Wednesday Night 0.50
Wednesday 0.25
Washington Pass Precipitation Forecast
Monday Night 1.00
Wednesday 0.75 -1.00
Wednesday Night 0.50 - 0.75
Wednesday 0.25
Leavenworth Precipitation Forecast
Monday Night 0.50
Wednesday 0.25 - 0.50
Wednesday Night 0.25
Wednesday LT 0.10
Stevens Pass Precipitation Forecast
Monday Night 0.50
Wednesday 0.50 - 0.75
Wednesday Night 0.50
Wednesday 0.25
Snoqualmie Pass Precipitation Forecast
Monday Night 1.00 - 1.50
Wednesday 1.00
Wednesday Night 0.75
Wednesday 0.25
Mission Ridge Precipitation Forecast
Monday Night 1.00 - 1.50
Wednesday 0.50
Wednesday Night LT 0.25
Wednesday 0
Crystal Mt Precipitation Forecast
Monday Night 1.50 - 2.00
Wednesday 0.75
Wednesday Night 0.25
Wednesday LT 0.10
Paradise Precipitation Forecast
Monday Night 2.00
Wednesday 1.50
Wednesday Night 1.00
Wednesday LT 0.25
White Pass Precipitation Forecast
Monday Night 1.00
Wednesday 1.00
Wednesday Night 0.75
Wednesday LT 0.10
Mt Hood Meadows Precipitation Forecast
Monday Night 1.00
Wednesday 1.00 - 1.50
Wednesday Night 0.75
Wednesday 0
Timberline Precipitation Forecast
Monday Night 1.00
Wednesday 1.50
Wednesday Night 0.75
Wednesday 0

Free Winds at 5000' (mph)

Hurricane Ridge Mt. Baker Stevens to Snoqualmie Pass Mt. Rainier Mt. Hood
Monday Evening S 45 - 65 SE 35 - 50 SE 30 - 45 SSE 30 - 45 S 40 - 60
Monday Night SE 25 - 35 SSW 25 - 35 SSW 35 - 50 SSW 35 - 50 SSW 45 - 65
Tuesday Morning SW 25 - 35 SSE 15 - 25 S 20 - 30 SSW 20 - 30 SW 40 - 60
Hurricane Ridge Elevation
Monday Evening S 45 - 65
Monday Night SE 25 - 35
Tuesday Morning SW 25 - 35
Tuesday Afternoon SW 25 - 35
Mt. Baker Elevation
Monday Evening SE 35 - 50
Monday Night SSW 25 - 35
Tuesday Morning SSE 15 - 25
Tuesday Afternoon SW 20 - 30
Stevens and Snoqualmie Pass Elevation
Monday Evening SE 30 - 45
Monday Night SSW 35 - 50
Tuesday Morning S 20 - 30
Tuesday Afternoon WSW 30 - 45
Mt. Rainier Elevation
Monday Evening SSE 30 - 45
Monday Night SSW 35 - 50
Tuesday Morning SSW 20 - 30
Tuesday Afternoon WSW 30 - 45
Mt. Hood Elevation
Monday Evening S 40 - 60
Monday Night SSW 45 - 65
Tuesday Morning SW 40 - 60
Tuesday Afternoon WSW 40 - 60
Hurricane Ridge Direction - Speed
Monday Evening S 45 - 65
Monday Night SE 25 - 35
Tuesday Morning SW 25 - 35
Tuesday Afternoon SW 25 - 35
Mt. Baker Direction - Speed
Monday Evening SE 35 - 50
Monday Night SSW 25 - 35
Tuesday Morning SSE 15 - 25
Tuesday Afternoon SW 20 - 30
Stevens and Snoqualmie Pass Direction - Speed
Monday Evening SE 30 - 45
Monday Night SSW 35 - 50
Tuesday Morning S 20 - 30
Tuesday Afternoon WSW 30 - 45
Mt. Rainier Direction - Speed
Monday Evening SSE 30 - 45
Monday Night SSW 35 - 50
Tuesday Morning SSW 20 - 30
Tuesday Afternoon WSW 30 - 45
Mt. Hood Direction - Speed
Monday Evening S 40 - 60
Monday Night SSW 45 - 65
Tuesday Morning SW 40 - 60
Tuesday Afternoon WSW 40 - 60

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
Monday Evening S 50 - 70 SSW 35 - 50 SW 45 - 65 SW 50 - 70 WSW 55 - 75
Monday Night SW 45 - 65 SW 40 - 60 SW 55 - 75 SW 55 - 75 SW 65 - 85
Tuesday Morning SW 25 - 35 SW 35 - 50 WSW 50 - 70 SW 60 - 80 SW 80 - 100
Mt. Baker Direction - Speed
Monday Evening S 50 - 70
Monday Night SW 45 - 65
Tuesday Morning SW 25 - 35
Tuesday Afternoon SW 40 - 60
Washington Pass Direction - Speed
Monday Evening SSW 35 - 50
Monday Night SW 40 - 60
Tuesday Morning SW 35 - 50
Tuesday Afternoon WSW 35 - 50
Stevens and Snoqualmie Pass Direction - Speed
Monday Evening SW 45 - 65
Monday Night SW 55 - 75
Tuesday Morning WSW 50 - 70
Tuesday Afternoon WSW 55 - 75
Mt. Rainier Direction - Speed
Monday Evening SW 50 - 70
Monday Night SW 55 - 75
Tuesday Morning SW 60 - 80
Tuesday Afternoon WSW 50 - 70
Mt. Hood Direction - Speed
Monday Evening WSW 55 - 75
Monday Night SW 65 - 85
Tuesday Morning SW 80 - 100
Tuesday Afternoon WSW 65 - 85

Extended Weather Synopsis for Wednesday night through Wednesday

Wednesday night, a compact and deeping low offshore will lift a warm front across the region, bringing rain and snow, heaviest over NW Washington.

The is currently forecast to make landfall near the northern tip of Vancouver Island on Thursday morning and may bring another round of strong winds, particularly to NW Washington on Thursday morning. The associated cold front will spread light to moderate rain and snow to all areas during the day on Thursday, with the heaviest rain and snow again over NW Washington. 

This strong storm will bring rapid cooling behind the front with light snow showers and windy conditions following the front Thursday night.

Snow showers decrease and end Friday morning as weak ridging tries to gain a hold, with another frontal system poised offshore.

Extended Snow/Freezing Levels

Mt. Baker Snoqualmie Pass Mt. Hood Easterly Flow *
Wednesday Night Snow Level 2500' - 3500' 3500' - 5500' 6500' - 7500' *
Thursday Snow Level 4000' - 5000' 5000' - 6000' 6000' - 7500'
Thursday Night Snow Level 2000' - 3500' 2500' - 4000' 3000' - 4500'
Mt. Baker Elevation
Wednesday Night Snow Level
2500' - 3500'
(Easterly Flow *)
Thursday Snow Level
4000' - 5000'
Thursday Night Snow Level
2000' - 3500'
Friday Snow Level
0' - 2000'
Snoqualmie Pass Elevation
Wednesday Night Snow Level
3500' - 5500'
(Easterly Flow *)
Thursday Snow Level
5000' - 6000'
Thursday Night Snow Level
2500' - 4000'
Friday Snow Level
0' - 2000'
Mt. Hood Elevation
Wednesday Night Snow Level
6500' - 7500'
(Easterly Flow *)
Thursday Snow Level
6000' - 7500'
Thursday Night Snow Level
3000' - 4500'
Friday Snow Level
500' - 2500'

* 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 Dec 17, 2018

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