Issued: 1:14 PM PST Friday, November 13, 2020
by Dennis D'Amico

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

Welcome back! We are starting the 2020-21 forecast season a bit early and in style with plenty of snow to talk about. We hope everyone has a great winter season - we're just getting started.

An intense low-pressure system passed through Vancouver, BC on Friday, walloping the Pacific Northwest with its first widespread dump of snow.  Water amounts were generally 1-2 inches with this storm along the west slopes of the Cascades and Mt. Hood and 0.50" or less on the east slopes. Corresponding snowfall totals were 1-2+ ft and 6" or less respectively.

Light to occasionally moderate showers will continue as the low passes into the interior of B.C. Friday night through mid-day Saturday with further light snow accumulations mainly for the west slopes of the Cascades and Mt. Hood. Look for slightly higher totals (6+ inches) where a Puget Sound Convergence zone sets up between Stevens Pass and Hwy 20 W. Expect moderate to locally strong westerly ridgeline winds to continue overnight.

A strong winter-like jet will slam the triple point of a frontal system into northern Oregon and the south Washington Cascades on Saturday night where the heaviest snow (1-2 ft) is expected. Lesser amounts will be seen further north as a weakening occluded front passes through Saturday night.  Moderate westerly post-frontal flow should more evenly spread precipitation around on Sunday in the form of persistent showers, with significant new snow accumulations along the west slopes of the Cascades and Mt. Hood above 3000-4000 ft and lesser amounts in the Crystal area (blocking likely) and along the east side of the Cascades. Keep an eye out as snow levels begin to creep up Saturday night through Sunday morning into the 3000-4000 ft range for the central and south Washington Cascades and ~5500' at Mt Hood. 

Weather Forecast

Hurricane Ridge
Friday Night Mostly cloudy with light snow showers. Strong ridgeline winds.
Mt. Baker
Friday Night Cloudy with light snow showers. Strong ridgeline winds.
Washington Pass and Leavenworth
Friday Night Mostly cloudy with light snow showers.Strong ridgeline winds.
Stevens and Snoqualmie Pass
Friday Night Light snow showers, moderate near Puget Sound Convergence Zone. Moderate west winds at Pass level. Strong ridgeline winds.
Mt. Rainier, Crystal and White Pass
Friday Night Light to occasionally moderate snow showers. Strong ridgeline winds.
Mt. Hood
Friday Night Light to moderate snow showers. Very windy.

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 2000' 2000' 2000' 2000' 2000' 2000' 2500' 3000'
Friday Night Snow Level 2000' 2000' 1500' 1500' 2000' 2000' 2500' 2500'
Saturday Morning Snow Level 2000' 2000' 1500' 1500' 2000' 2000' 2500' 3000'
Saturday Afternoon Snow Level * 2500' 2000' 2000' 2500' 2500' 2500' 2500' 3500'
Saturday Evening Snow Level * 2500' 2000' 2000' 2000' 2500' 2500' 3000' 3500'
Saturday Night Snow Level * 4500' 2500' 2000' 2500' 2500' 3500' 4000' 5500'
Sunday Morning Snow Level 3500' 3000' 3000' 2500' 4000' 4000' 4500' 5000'
Hurricane Ridge Elevation
Friday Evening Snow Level
2000'
Friday Night Snow Level
2000'
Saturday Morning Snow Level
2000'
Saturday Afternoon Snow Level
2500'
(Easterly Flow *)
Saturday Evening Snow Level
2500'
(Easterly Flow *)
Saturday Night Snow Level
4500'
(Easterly Flow *)
Sunday Morning Snow Level
3500'
Sunday Afternoon Snow Level
3500'
Mt. Baker Elevation
Friday Evening Snow Level
2000'
Friday Night Snow Level
2000'
Saturday Morning Snow Level
2000'
Saturday Afternoon Snow Level
2000'
(Easterly Flow *)
Saturday Evening Snow Level
2000'
(Easterly Flow *)
Saturday Night Snow Level
2500'
(Easterly Flow *)
Sunday Morning Snow Level
3000'
Sunday Afternoon Snow Level
3000'
Washington Pass Elevation
Friday Evening Snow Level
2000'
Friday Night Snow Level
1500'
Saturday Morning Snow Level
1500'
Saturday Afternoon Snow Level
2000'
(Easterly Flow *)
Saturday Evening Snow Level
2000'
(Easterly Flow *)
Saturday Night Snow Level
2000'
(Easterly Flow *)
Sunday Morning Snow Level
3000'
Sunday Afternoon Snow Level
3000'
Leavenworth Elevation
Friday Evening Snow Level
2000'
Friday Night Snow Level
1500'
Saturday Morning Snow Level
1500'
Saturday Afternoon Snow Level
2500'
(Easterly Flow *)
Saturday Evening Snow Level
2000'
(Easterly Flow *)
Saturday Night Snow Level
2500'
(Easterly Flow *)
Sunday Morning Snow Level
2500'
Sunday Afternoon Snow Level
3500'
Stevens Pass Elevation
Friday Evening Snow Level
2000'
Friday Night Snow Level
2000'
Saturday Morning Snow Level
2000'
Saturday Afternoon Snow Level
2500'
(Easterly Flow *)
Saturday Evening Snow Level
2500'
(Easterly Flow *)
Saturday Night Snow Level
2500'
(Easterly Flow *)
Sunday Morning Snow Level
4000'
Sunday Afternoon Snow Level
3000'
Snoqualmie Pass Elevation
Friday Evening Snow Level
2000'
Friday Night Snow Level
2000'
Saturday Morning Snow Level
2000'
Saturday Afternoon Snow Level
2500'
(Easterly Flow *)
Saturday Evening Snow Level
2500'
(Easterly Flow *)
Saturday Night Snow Level
3500'
(Easterly Flow *)
Sunday Morning Snow Level
4000'
Sunday Afternoon Snow Level
3000'
Mt. Rainier & Crystal Elevation
Friday Evening Snow Level
2500'
Friday Night Snow Level
2500'
Saturday Morning Snow Level
2500'
Saturday Afternoon Snow Level
2500'
(Easterly Flow *)
Saturday Evening Snow Level
3000'
(Easterly Flow *)
Saturday Night Snow Level
4000'
(Easterly Flow *)
Sunday Morning Snow Level
4500'
Sunday Afternoon Snow Level
3500'
Mt. Hood Elevation
Friday Evening Snow Level
3000'
Friday Night Snow Level
2500'
Saturday Morning Snow Level
3000'
Saturday Afternoon Snow Level
3500'
(Easterly Flow *)
Saturday Evening Snow Level
3500'
(Easterly Flow *)
Saturday Night Snow Level
5500'
(Easterly Flow *)
Sunday Morning Snow Level
5000'
Sunday Afternoon Snow Level
4500'

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

Free Winds at 5000' (mph)

Hurricane Ridge Mt. Baker Stevens to Snoqualmie Pass Mt. Rainier Mt. Hood
Friday Evening W 25 - 35 SW 25 - 35 WSW 25 - 35 W 20 - 30 W 35 - 45
Friday Night W 20 - 30 SW 15 - 25 W 20 - 30 W 20 - 30 W 30 - 40
Saturday Morning W 10 - 20 SW 5 - 15 W 10 - 20 W 10 - 20 W 25 - 35
Hurricane Ridge Elevation
Friday Evening W 25 - 35
Friday Night W 20 - 30
Saturday Morning W 10 - 20
Saturday Afternoon SE 5 - 15
Mt. Baker Elevation
Friday Evening SW 25 - 35
Friday Night SW 15 - 25
Saturday Morning SW 5 - 15
Saturday Afternoon SE 5 - 15
Stevens and Snoqualmie Pass Elevation
Friday Evening WSW 25 - 35
Friday Night W 20 - 30
Saturday Morning W 10 - 20
Saturday Afternoon SE 5 - 15
Mt. Rainier Elevation
Friday Evening W 20 - 30
Friday Night W 20 - 30
Saturday Morning W 10 - 20
Saturday Afternoon SE 5 - 15
Mt. Hood Elevation
Friday Evening W 35 - 45
Friday Night W 30 - 40
Saturday Morning W 25 - 35
Saturday Afternoon S 10 - 20
Hurricane Ridge Direction - Speed
Friday Evening W 25 - 35
Friday Night W 20 - 30
Saturday Morning W 10 - 20
Saturday Afternoon SE 5 - 15
Mt. Baker Direction - Speed
Friday Evening SW 25 - 35
Friday Night SW 15 - 25
Saturday Morning SW 5 - 15
Saturday Afternoon SE 5 - 15
Stevens and Snoqualmie Pass Direction - Speed
Friday Evening WSW 25 - 35
Friday Night W 20 - 30
Saturday Morning W 10 - 20
Saturday Afternoon SE 5 - 15
Mt. Rainier Direction - Speed
Friday Evening W 20 - 30
Friday Night W 20 - 30
Saturday Morning W 10 - 20
Saturday Afternoon SE 5 - 15
Mt. Hood Direction - Speed
Friday Evening W 35 - 45
Friday Night W 30 - 40
Saturday Morning W 25 - 35
Saturday Afternoon S 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 Evening W 40 - 50 W 50 - 60 W 45 - 55 W 40 - 50 W 50 - 60
Friday Night W 30 - 40 W 50 - 60 W 40 - 50 SW 40 - 50 SW 45 - 55
Saturday Morning W 20 - 30 W 30 - 40 W 30 - 40 W 35 - 45 W 35 - 45
Mt. Baker Direction - Speed
Friday Evening W 40 - 50
Friday Night W 30 - 40
Saturday Morning W 20 - 30
Saturday Afternoon SW 20 - 30
Washington Pass Direction - Speed
Friday Evening W 50 - 60
Friday Night W 50 - 60
Saturday Morning W 30 - 40
Saturday Afternoon SW 5 - 15
Stevens and Snoqualmie Pass Direction - Speed
Friday Evening W 45 - 55
Friday Night W 40 - 50
Saturday Morning W 30 - 40
Saturday Afternoon SW 20 - 30
Mt. Rainier Direction - Speed
Friday Evening W 40 - 50
Friday Night SW 40 - 50
Saturday Morning W 35 - 45
Saturday Afternoon SW 30 - 40
Mt. Hood Direction - Speed
Friday Evening W 50 - 60
Friday Night SW 45 - 55
Saturday Morning W 35 - 45
Saturday Afternoon SW 40 - 60

Extended Weather Synopsis for Sunday night through Tuesday

Look for shower activity to wind down Sunday night.  A developing low-pressure system well off the coast of Oregon will begin to lift warm frontal precipitation across northern Oregon Monday morning and Washington state during the day. This warm front will likely bring a quick blast of snow, followed by rapidly rising snow levels following the frontal passage.

Precipitation will largely shut-off Monday night as we sit in the warm sector, waiting for the low's trailing cold front to pass through some time on Tuesday. Strong offshore flow will develop as the low deepens Monday night, expect moderate to strong easterly winds to develop in the Cascades Passes and potentially extend up to crest-level along the west slopes of the Cascades. The further north the center of the low tracks Monday night, the longer we'll sit in warm air on Tuesday and the weaker the frontal passage will be both in terms of precipitation and cooling when it finally passes through.

Extended Snow/Freezing Levels

Mt. Baker Snoqualmie Pass Mt. Hood Easterly Flow *
Sunday Night Snow Level 2000' - 3000' 2500' - 3500' 4000' - 5000'
Monday Snow Level 3000' - 4000' 3000' - 4000' 6500' - 7500' *
Monday Night Snow Level 5000' - 6000' 5500' - 6500' 8500' - 9500' *
Mt. Baker Elevation
Sunday Night Snow Level
2000' - 3000'
Monday Snow Level
3000' - 4000'
(Easterly Flow *)
Monday Night Snow Level
5000' - 6000'
(Easterly Flow *)
Tuesday Snow Level
5000' - 6000'
Snoqualmie Pass Elevation
Sunday Night Snow Level
2500' - 3500'
Monday Snow Level
3000' - 4000'
(Easterly Flow *)
Monday Night Snow Level
5500' - 6500'
(Easterly Flow *)
Tuesday Snow Level
5000' - 6000'
Mt. Hood Elevation
Sunday Night Snow Level
4000' - 5000'
Monday Snow Level
6500' - 7500'
(Easterly Flow *)
Monday Night Snow Level
8500' - 9500'
(Easterly Flow *)
Tuesday Snow Level
6000' - 7000'

* 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 Apr 12, 2020

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.