Issued: 7:11 AM PST Monday, December 7, 2020
by Dennis D'Amico

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

Weather Synopsis for Monday & Thursday

Warm frontal moisture is on the proverbial doorstep this morning with radar showing heavier precipitation glancing the northern Olymipc peninsula and parts of NE Whatcom county.  Precipitation should largely stay in this position and likely slightly shift north today keeping the majority of the area dry. Mild temperatures and high freezing/snow levels will be the big story today, so for areas in the Olympics and north Cascades that do see precipitation, it will be in liquid form along with moderate to strong S-SW winds. Cool offshore easterly flow in the Passes is causing temperature inversions at Pass level. While that trend will continue today, the W-SW aloft is strong enough that warm air is overriding the cooler surface air with upper elevation temperatures well above freezing. 

The Washington Pass area will likely fluctuate between above and below freezing temperatures today.  That will change tonight as W-SW winds increase and push in high freezing levels even into the Northeast Cascades along with light to moderate precipitation. More moderate precipitation will start in the northwest Cascades this evening and barely make it down to the I-90 and Hwy 2 corridors by early Tuesday morning. In general the frontal boundary's southern progression has slowed, and it looks to weaken and eventually wash out during the day on Tuesday.  This means a slow cooling trend, rain for almost all elevations, and lighter precipitation amounts for the south Washington Cascades and Mt Hood.  Westerly ridgeline winds will also be strong through tomorrow as the frontal boundary sags south. 

Weather Forecast

Hurricane Ridge
Mt. Baker
Washington Pass and Leavenworth
Stevens and Snoqualmie Pass
Mt. Rainier, Crystal and White Pass
Mt. Hood

Snow/Freezing Level (ft)

Hurricane Ridge Mt. Baker Washington Pass Leavenworth Stevens Pass Snoqualmie Pass Mt. Rainier, Crystal & White Pass Mt. Hood
Monday Morning Freezing Level * 7500' 6500' 4000' 6000' 8000' 9000' 9000' 11500'
Monday Afternoon Freezing Level * 9000' 6500' 4500' 8000' 9000' 9000' 10000' 11500'
Monday Evening Snow Level * 10000' 7000' 7500' 9000' 9000' 9000' 9000' 12000'
Monday Night Snow Level 10000' 8000' 8500' 9000' 9000' 9000' 9000' 12000'
Tuesday Morning Snow Level 7000' 6000' 8000' 8000' 8000' 8000' 8000' 11000'
Hurricane Ridge Elevation
Monday Morning Freezing Level
7500'
(Easterly Flow *)
Monday Afternoon Freezing Level
9000'
(Easterly Flow *)
Monday Evening Snow Level
10000'
(Easterly Flow *)
Monday Night Snow Level
10000'
Tuesday Morning Snow Level
7000'
Tuesday Afternoon Snow Level
6000'
Mt. Baker Elevation
Monday Morning Freezing Level
6500'
(Easterly Flow *)
Monday Afternoon Freezing Level
6500'
(Easterly Flow *)
Monday Evening Snow Level
7000'
(Easterly Flow *)
Monday Night Snow Level
8000'
Tuesday Morning Snow Level
6000'
Tuesday Afternoon Snow Level
5000'
Washington Pass Elevation
Monday Morning Freezing Level
4000'
(Easterly Flow *)
Monday Afternoon Freezing Level
4500'
(Easterly Flow *)
Monday Evening Snow Level
7500'
(Easterly Flow *)
Monday Night Snow Level
8500'
Tuesday Morning Snow Level
8000'
Tuesday Afternoon Snow Level
6000'
Leavenworth Elevation
Monday Morning Freezing Level
6000'
(Easterly Flow *)
Monday Afternoon Freezing Level
8000'
(Easterly Flow *)
Monday Evening Snow Level
9000'
(Easterly Flow *)
Monday Night Snow Level
9000'
Tuesday Morning Snow Level
8000'
Tuesday Afternoon Snow Level
7000'
Stevens Pass Elevation
Monday Morning Freezing Level
8000'
(Easterly Flow *)
Monday Afternoon Freezing Level
9000'
(Easterly Flow *)
Monday Evening Snow Level
9000'
(Easterly Flow *)
Monday Night Snow Level
9000'
Tuesday Morning Snow Level
8000'
Tuesday Afternoon Snow Level
6000'
Snoqualmie Pass Elevation
Monday Morning Freezing Level
9000'
(Easterly Flow *)
Monday Afternoon Freezing Level
9000'
(Easterly Flow *)
Monday Evening Snow Level
9000'
(Easterly Flow *)
Monday Night Snow Level
9000'
Tuesday Morning Snow Level
8000'
Tuesday Afternoon Snow Level
6000'
Mt. Rainier & Crystal Elevation
Monday Morning Freezing Level
9000'
(Easterly Flow *)
Monday Afternoon Freezing Level
10000'
(Easterly Flow *)
Monday Evening Snow Level
9000'
(Easterly Flow *)
Monday Night Snow Level
9000'
Tuesday Morning Snow Level
8000'
Tuesday Afternoon Snow Level
7000'
Mt. Hood Elevation
Monday Morning Freezing Level
11500'
(Easterly Flow *)
Monday Afternoon Freezing Level
11500'
(Easterly Flow *)
Monday Evening Snow Level
12000'
(Easterly Flow *)
Monday Night Snow Level
12000'
Tuesday Morning Snow Level
11000'
Tuesday Afternoon Snow Level
8000'

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

Free Winds at 5000' (mph)

Hurricane Ridge Mt. Baker Stevens to Snoqualmie Pass Mt. Rainier Mt. Hood
Monday Morning SW 15 - 25 SSW 20 - 30 SW 15 - 25 SW 10 - 20 SW 5 - 15
Monday Afternoon S 15 - 25 S 20 - 30 SW 15 - 25 SW 10 - 20 SW 10 - 20
Monday Evening SW 30 - 40 S 25 - 35 SW 20 - 30 SW 20 - 30 SW 5 - 15
Monday Night SW 30 - 40 S 35 - 45 SW 25 - 35 WSW 25 - 35 SW 15 - 25
Tuesday Morning W 15 - 25 SW 10 - 20 WSW 30 - 40 WSW 30 - 40 SW 15 - 25
Hurricane Ridge Elevation
Monday Morning SW 15 - 25
Monday Afternoon S 15 - 25
Monday Evening SW 30 - 40
Monday Night SW 30 - 40
Tuesday Morning W 15 - 25
Tuesday Afternoon WNW 10 - 20
Mt. Baker Elevation
Monday Morning SSW 20 - 30
Monday Afternoon S 20 - 30
Monday Evening S 25 - 35
Monday Night S 35 - 45
Tuesday Morning SW 10 - 20
Tuesday Afternoon W 5 - 15
Stevens and Snoqualmie Pass Elevation
Monday Morning SW 15 - 25
Monday Afternoon SW 15 - 25
Monday Evening SW 20 - 30
Monday Night SW 25 - 35
Tuesday Morning WSW 30 - 40
Tuesday Afternoon W 15 - 25
Mt. Rainier Elevation
Monday Morning SW 10 - 20
Monday Afternoon SW 10 - 20
Monday Evening SW 20 - 30
Monday Night WSW 25 - 35
Tuesday Morning WSW 30 - 40
Tuesday Afternoon WSW 15 - 25
Mt. Hood Elevation
Monday Morning SW 5 - 15
Monday Afternoon SW 10 - 20
Monday Evening SW 5 - 15
Monday Night SW 15 - 25
Tuesday Morning SW 15 - 25
Tuesday Afternoon W 15 - 25
Hurricane Ridge Direction - Speed
Monday Morning SW 15 - 25
Monday Afternoon S 15 - 25
Monday Evening SW 30 - 40
Monday Night SW 30 - 40
Tuesday Morning W 15 - 25
Tuesday Afternoon WNW 10 - 20
Mt. Baker Direction - Speed
Monday Morning SSW 20 - 30
Monday Afternoon S 20 - 30
Monday Evening S 25 - 35
Monday Night S 35 - 45
Tuesday Morning SW 10 - 20
Tuesday Afternoon W 5 - 15
Stevens and Snoqualmie Pass Direction - Speed
Monday Morning SW 15 - 25
Monday Afternoon SW 15 - 25
Monday Evening SW 20 - 30
Monday Night SW 25 - 35
Tuesday Morning WSW 30 - 40
Tuesday Afternoon W 15 - 25
Mt. Rainier Direction - Speed
Monday Morning SW 10 - 20
Monday Afternoon SW 10 - 20
Monday Evening SW 20 - 30
Monday Night WSW 25 - 35
Tuesday Morning WSW 30 - 40
Tuesday Afternoon WSW 15 - 25
Mt. Hood Direction - Speed
Monday Morning SW 5 - 15
Monday Afternoon SW 10 - 20
Monday Evening SW 5 - 15
Monday Night SW 15 - 25
Tuesday Morning SW 15 - 25
Tuesday Afternoon W 15 - 25

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 Morning SW 35 - 45 SW 35 - 45 SW 30 - 40 SW 20 - 30 W 10 - 20
Monday Afternoon SW 35 - 45 SW 35 - 45 SW 40 - 50 SW 30 - 40 WSW 15 - 25
Monday Evening SW 35 - 45 SW 45 - 55 SW 45 - 55 SW 35 - 45 WSW 20 - 30
Monday Night SW 45 - 55 SW 55 - 65 SW 50 - 60 SW 45 - 55 W 30 - 40
Tuesday Morning SW 30 - 40 WSW 40 - 50 SW 55 - 65 SW 45 - 55 WSW 40 - 50
Mt. Baker Direction - Speed
Monday Morning SW 35 - 45
Monday Afternoon SW 35 - 45
Monday Evening SW 35 - 45
Monday Night SW 45 - 55
Tuesday Morning SW 30 - 40
Tuesday Afternoon W 20 - 30
Washington Pass Direction - Speed
Monday Morning SW 35 - 45
Monday Afternoon SW 35 - 45
Monday Evening SW 45 - 55
Monday Night SW 55 - 65
Tuesday Morning WSW 40 - 50
Tuesday Afternoon W 25 - 35
Stevens and Snoqualmie Pass Direction - Speed
Monday Morning SW 30 - 40
Monday Afternoon SW 40 - 50
Monday Evening SW 45 - 55
Monday Night SW 50 - 60
Tuesday Morning SW 55 - 65
Tuesday Afternoon WSW 40 - 50
Mt. Rainier Direction - Speed
Monday Morning SW 20 - 30
Monday Afternoon SW 30 - 40
Monday Evening SW 35 - 45
Monday Night SW 45 - 55
Tuesday Morning SW 45 - 55
Tuesday Afternoon WSW 35 - 45
Mt. Hood Direction - Speed
Monday Morning W 10 - 20
Monday Afternoon WSW 15 - 25
Monday Evening WSW 20 - 30
Monday Night W 30 - 40
Tuesday Morning WSW 40 - 50
Tuesday Afternoon WSW 35 - 45

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 Dec 6, 2020

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