Issued: 7:23 AM PST Monday, January 8, 2018
by Robert Hahn

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

Weather Synopsis for Monday & Saturday

A frontal zone connecting weak weather systems will lift north today as moisture rides over a broad ridge centered on the Rockies. To the west, an elongated trough will gradually approach our coastal waters. 

Tonight, the trough splits and ejects a weak shortwave trough and associated surface low northeastward. The low reaches Vancouver Island and an associated surface front that should arrive over the Pacific Northwest by daybreak. Most of the energy from the elongated trough takes a southerly track, spawning a cutoff low which should move into the California coastal waters.

On Tuesday, light to moderate onshore flow should continue shower activity on a westerly flow, particularly west of the Cascade crest with convergence bands developing and focused from Snoqualmie to Stevens Pass. Onshore flow and shower activity continue Tuesday night.

Weather Forecast

Olympics
Monday Occasional light rain and snow.
Monday Night Increasing light rain and snow.
Tuesday Increasing light showers.
Washington Cascades near and west of the Crest including Stevens, Snoqualmie and White Passes
Monday Decreasing light rain or snow in the north, then becoming cloudy. Occasional very light sprinkles in the morning, then remaining cloudy.
Monday Night Increasing light rain or snow mainly after midnight.
Tuesday Light rain or snow showers, generally decreasing in intensity, but heaviest in convergence in the Stevens to Snoqualmie area in the late afternoon.
East Slopes of the Washington Cascades
Monday Mostly cloudy.
Monday Night Increasing light rain and freezing rain at lower elevations with snow at higher elevations.
Tuesday Decreasing light rain and snow showers, particularly higher elevations.
Mt. Hood
Monday Cloudy.
Monday Night Increasing light rain and snow.
Tuesday Light rain and snow showers.

Snow/Freezing Level (ft)

Hurricane Ridge Mt. Baker Washington Pass Leavenworth Stevens Pass Snoqualmie Pass Mt. Rainier, Crystal & White Pass Mt. Hood
Monday Morning Snow Level * 4500' 4000' 4000' ' ' 5000' ' 6500'
Monday Afternoon Snow Level * 4000' 4000' 4000' ' ' 4500' ' 6500'
Monday Night Snow Level * 3500' 3500' 3000' ' ' 4000' ' 6000'
Tuesday Morning Snow Level 3000' 3000' 3500' ' ' 3000' ' 4500'
Tuesday Afternoon Snow Level 2500' 2500' 2500' ' ' 2500' ' 3000'
Hurricane Ridge Elevation
Monday Morning Snow Level
4500'
(Easterly Flow *)
Monday Afternoon Snow Level
4000'
(Easterly Flow *)
Monday Night Snow Level
3500'
(Easterly Flow *)
Tuesday Morning Snow Level
3000'
Tuesday Afternoon Snow Level
2500'
Tuesday Night Snow Level
2000'
Mt. Baker Elevation
Monday Morning Snow Level
4000'
(Easterly Flow *)
Monday Afternoon Snow Level
4000'
(Easterly Flow *)
Monday Night Snow Level
3500'
(Easterly Flow *)
Tuesday Morning Snow Level
3000'
Tuesday Afternoon Snow Level
2500'
Tuesday Night Snow Level
1500'
Washington Pass Elevation
Monday Morning Snow Level
4000'
(Easterly Flow *)
Monday Afternoon Snow Level
4000'
(Easterly Flow *)
Monday Night Snow Level
3000'
(Easterly Flow *)
Tuesday Morning Snow Level
3500'
Tuesday Afternoon Snow Level
2500'
Tuesday Night Snow Level
1500'
Leavenworth Elevation
Monday Morning Snow Level
'
(Easterly Flow *)
Monday Afternoon Snow Level
'
(Easterly Flow *)
Monday Night Snow Level
'
(Easterly Flow *)
Tuesday Morning Snow Level
'
Tuesday Afternoon Snow Level
'
Tuesday Night Snow Level
'
Stevens Pass Elevation
Monday Morning Snow Level
'
(Easterly Flow *)
Monday Afternoon Snow Level
'
(Easterly Flow *)
Monday Night Snow Level
'
(Easterly Flow *)
Tuesday Morning Snow Level
'
Tuesday Afternoon Snow Level
'
Tuesday Night Snow Level
'
Snoqualmie Pass Elevation
Monday Morning Snow Level
5000'
(Easterly Flow *)
Monday Afternoon Snow Level
4500'
(Easterly Flow *)
Monday Night Snow Level
4000'
(Easterly Flow *)
Tuesday Morning Snow Level
3000'
Tuesday Afternoon Snow Level
2500'
Tuesday Night Snow Level
1500'
Mt. Rainier & Crystal Elevation
Monday Morning Snow Level
'
(Easterly Flow *)
Monday Afternoon Snow Level
'
(Easterly Flow *)
Monday Night Snow Level
'
(Easterly Flow *)
Tuesday Morning Snow Level
'
Tuesday Afternoon Snow Level
'
Tuesday Night Snow Level
'
Mt. Hood Elevation
Monday Morning Snow Level
6500'
(Easterly Flow *)
Monday Afternoon Snow Level
6500'
(Easterly Flow *)
Monday Night Snow Level
6000'
(Easterly Flow *)
Tuesday Morning Snow Level
4500'
Tuesday Afternoon Snow Level
3000'
Tuesday Night Snow Level
2000'

* 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

Saturday Saturday
Hurricane Ridge LT 0.25 LT 0.25
Mt Baker Ski Area 0.25 - 0.50 LT 0.25
Washington Pass LT 0.25 LT 0.25
Stevens Pass LT 0.25 0 - 0.50
Snoqualmie Pass LT 0.25 0.50 - 0.75
Mission Ridge LT 0.25 LT 0.10
Crystal Mt LT 0.25 LT 0.25
Paradise 0.25 - 0.50 0.25 - 0.50
White Pass LT 0.25 LT 0.25
Mt Hood Meadows LT 0.25 LT 0.25
LT 0.25 LT 0.25

Free Winds at 5000' (mph)

Hurricane Ridge Mt. Baker Stevens to Snoqualmie Pass Mt. Rainier Mt. Hood
Monday Morning S 10 - 20 S 15 - 25 S 10 - 20 --- - S 10 - 20
Monday Afternoon SSE 15 - 25 SSE 15 - 25 SSE 10 - 20 --- - SSE 10 - 20
Monday Night SSE 15 - 25 SSW 15 - 25 SSE 15 - 25 --- - SSE 10 - 20
Tuesday Morning WSW 15 - 25 SW 10 - 20 WSW 10 - 20 --- - WSW 10 - 20
Tuesday Afternoon WSW 20 - 30 SW 15 - 25 WSW 20 - 30 --- - WSW 20 - 30
Hurricane Ridge Elevation
Monday Morning S 10 - 20
Monday Afternoon SSE 15 - 25
Monday Night SSE 15 - 25
Tuesday Morning WSW 15 - 25
Tuesday Afternoon WSW 20 - 30
Tuesday Night WSW 15 - 25
Mt. Baker Elevation
Monday Morning S 15 - 25
Monday Afternoon SSE 15 - 25
Monday Night SSW 15 - 25
Tuesday Morning SW 10 - 20
Tuesday Afternoon SW 15 - 25
Tuesday Night WSW 15 - 25
Stevens and Snoqualmie Pass Elevation
Monday Morning S 10 - 20
Monday Afternoon SSE 10 - 20
Monday Night SSE 15 - 25
Tuesday Morning WSW 10 - 20
Tuesday Afternoon WSW 20 - 30
Tuesday Night WSW 15 - 25
Mt. Rainier Elevation
Monday Morning --- -
Monday Afternoon --- -
Monday Night --- -
Tuesday Morning --- -
Tuesday Afternoon --- -
Tuesday Night --- -
Mt. Hood Elevation
Monday Morning S 10 - 20
Monday Afternoon SSE 10 - 20
Monday Night SSE 10 - 20
Tuesday Morning WSW 10 - 20
Tuesday Afternoon WSW 20 - 30
Tuesday Night WSW 20 - 30
Hurricane Ridge Direction - Speed
Monday Morning S 10 - 20
Monday Afternoon SSE 15 - 25
Monday Night SSE 15 - 25
Tuesday Morning WSW 15 - 25
Tuesday Afternoon WSW 20 - 30
Tuesday Night WSW 15 - 25
Mt. Baker Direction - Speed
Monday Morning S 15 - 25
Monday Afternoon SSE 15 - 25
Monday Night SSW 15 - 25
Tuesday Morning SW 10 - 20
Tuesday Afternoon SW 15 - 25
Tuesday Night WSW 15 - 25
Stevens and Snoqualmie Pass Direction - Speed
Monday Morning S 10 - 20
Monday Afternoon SSE 10 - 20
Monday Night SSE 15 - 25
Tuesday Morning WSW 10 - 20
Tuesday Afternoon WSW 20 - 30
Tuesday Night WSW 15 - 25
Mt. Rainier Direction - Speed
Monday Morning --- -
Monday Afternoon --- -
Monday Night --- -
Tuesday Morning --- -
Tuesday Afternoon --- -
Tuesday Night --- -
Mt. Hood Direction - Speed
Monday Morning S 10 - 20
Monday Afternoon SSE 10 - 20
Monday Night SSE 10 - 20
Tuesday Morning WSW 10 - 20
Tuesday Afternoon WSW 20 - 30
Tuesday Night WSW 20 - 30

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

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

Previous forecast from Jan 7, 2018

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.