Issued: 11:18 AM PST Wednesday, January 3, 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 Wednesday & Wednesday

On Wednesday, the ridge has rebuilt over the Pacific Northwest keeping snow/freezing levels mild and offshore easterly flow in the light to moderate range through the short term. A weak shortwave trough which progressed to our east Tuesday night mixed the atmosphere slightly. This mixing has resulted in decreased low level cloud coverage. Isolated clouds along with cooler temperatures will be seen in the Cascade Passes, lower elevations along the east slopes of the Cascades and Mt. Hood.  A weak upper shortwave trough embedded in a open trough rotating off the California coast will begin to move northward on Wednesday.

On Wednesday night, the ridge shifts east of the Cascades as the weak upper shortwave trough continues to move northward off the Oregon Coast.

On Thursday, occasional light precipitation spreads into region as the weak shortwave loses its identity as it begins moves northward into the Pacific Northwest on SW flow ahead of a trough to the west.

On Thursday night, moisture increases ahead of the trough that is moving eastward off the coast of British Columbia 

Weather Forecast

Olympics
Wednesday Mostly sunny and mild.
Wednesday Night Mostly clear and mild with increasing clouds high clouds after midnight.
Thursday Clouds lowering in the morning with occasional light rain in the afternoon.
Washington Cascades near and west of the Crest including Stevens, Snoqualmie and White Passes
Wednesday Mostly sunny and mild with decreasing high and mid clouds in the South Cascades in the morning. Cooler temperatures and solated low clouds in the Cascade Passes.
Wednesday Night Mild with increasing high clouds in the south Cascades.
Thursday Clouds increase and lower with occasional light rain arriving in the south and then central Cascades by afternoon. Precipitation should be freezing rain or snow in the passes.
East Slopes of the Washington Cascades
Wednesday Mostly sunny and mild at higher elevations. Colder at low elevations with isolated low clouds in valleys.
Wednesday Night Mild at higher elevations with increasing clouds in the south. Colder at low elevations with isolated low clouds in valleys.
Thursday Clouds increase and occasional light rain, freezing rain or snow arrives in the south and then central Cascades by afternoon.
Mt. Hood
Wednesday Mostly sunny and mild with decreasing high and mid clouds in the morning . Cooler temperatures and solated low clouds in the Cascade Passes.
Wednesday Night Mild with increasing high clouds, lowering towards morning.
Thursday Clouds increase and light rain and high elevation snow arrives in the late morning hours.

Snow/Freezing Level (ft)

Hurricane Ridge Mt. Baker Washington Pass Leavenworth Stevens Pass Snoqualmie Pass Mt. Rainier, Crystal & White Pass Mt. Hood
Wednesday Morning Freezing Level * 9000' 8500' 7000' ' ' 8000' ' 10000'
Wednesday Night Freezing Level * 9500' 9500' 7000' ' ' 9500' ' 10000'
Thursday Afternoon Snow Level * 7000' 6500' 4500' ' ' 6000' ' 7000'
Wednesday Afternoon Freezing Level * 9500' 9000' 7500' ' ' 8500' ' 10000'
Thursday Morning Snow Level * 7500' 7500' 5500' ' ' 6000' ' 7500'
Hurricane Ridge Elevation
Wednesday Morning Freezing Level
9000'
(Easterly Flow *)
Wednesday Night Freezing Level
9500'
(Easterly Flow *)
Thursday Afternoon Snow Level
7000'
(Easterly Flow *)
Wednesday Afternoon Freezing Level
9500'
(Easterly Flow *)
Thursday Morning Snow Level
7500'
(Easterly Flow *)
Thursday Night Snow Level
7000'
(Easterly Flow *)
Mt. Baker Elevation
Wednesday Morning Freezing Level
8500'
(Easterly Flow *)
Wednesday Night Freezing Level
9500'
(Easterly Flow *)
Thursday Afternoon Snow Level
6500'
(Easterly Flow *)
Wednesday Afternoon Freezing Level
9000'
(Easterly Flow *)
Thursday Morning Snow Level
7500'
(Easterly Flow *)
Thursday Night Snow Level
7000'
(Easterly Flow *)
Washington Pass Elevation
Wednesday Morning Freezing Level
7000'
(Easterly Flow *)
Wednesday Night Freezing Level
7000'
(Easterly Flow *)
Thursday Afternoon Snow Level
4500'
(Easterly Flow *)
Wednesday Afternoon Freezing Level
7500'
(Easterly Flow *)
Thursday Morning Snow Level
5500'
(Easterly Flow *)
Thursday Night Snow Level
5000'
(Easterly Flow *)
Leavenworth Elevation
Wednesday Morning Freezing Level
'
(Easterly Flow *)
Wednesday Night Freezing Level
'
(Easterly Flow *)
Thursday Afternoon Snow Level
'
(Easterly Flow *)
Wednesday Afternoon Freezing Level
'
(Easterly Flow *)
Thursday Morning Snow Level
'
(Easterly Flow *)
Thursday Night Snow Level
'
(Easterly Flow *)
Stevens Pass Elevation
Wednesday Morning Freezing Level
'
(Easterly Flow *)
Wednesday Night Freezing Level
'
(Easterly Flow *)
Thursday Afternoon Snow Level
'
(Easterly Flow *)
Wednesday Afternoon Freezing Level
'
(Easterly Flow *)
Thursday Morning Snow Level
'
(Easterly Flow *)
Thursday Night Snow Level
'
(Easterly Flow *)
Snoqualmie Pass Elevation
Wednesday Morning Freezing Level
8000'
(Easterly Flow *)
Wednesday Night Freezing Level
9500'
(Easterly Flow *)
Thursday Afternoon Snow Level
6000'
(Easterly Flow *)
Wednesday Afternoon Freezing Level
8500'
(Easterly Flow *)
Thursday Morning Snow Level
6000'
(Easterly Flow *)
Thursday Night Snow Level
6500'
(Easterly Flow *)
Mt. Rainier & Crystal Elevation
Wednesday Morning Freezing Level
'
(Easterly Flow *)
Wednesday Night Freezing Level
'
(Easterly Flow *)
Thursday Afternoon Snow Level
'
(Easterly Flow *)
Wednesday Afternoon Freezing Level
'
(Easterly Flow *)
Thursday Morning Snow Level
'
(Easterly Flow *)
Thursday Night Snow Level
'
(Easterly Flow *)
Mt. Hood Elevation
Wednesday Morning Freezing Level
10000'
(Easterly Flow *)
Wednesday Night Freezing Level
10000'
(Easterly Flow *)
Thursday Afternoon Snow Level
7000'
(Easterly Flow *)
Wednesday Afternoon Freezing Level
10000'
(Easterly Flow *)
Thursday Morning Snow Level
7500'
(Easterly Flow *)
Thursday Night Snow Level
7000'
(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

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

Free Winds at 5000' (mph)

Hurricane Ridge Mt. Baker Stevens to Snoqualmie Pass Mt. Rainier Mt. Hood
Wednesday Morning SE 5 - 15 E 5 - 15 E 10 - 20 --- - E 10 - 20
Wednesday Afternoon ESE 5 - 15 E 5 - 15 E 10 - 20 --- - E 10 - 20
Wednesday Night SSE 5 - 15 ESE 5 - 15 E 10 - 20 --- - E 10 - 20
Thursday Morning SSE 5 - 15 ESE 5 - 15 ESE 10 - 20 --- - SE 5 - 15
Thursday Afternoon S 5 - 15 SE 5 - 15 SE 5 - 15 --- - SSE 5 - 15
Hurricane Ridge Elevation
Wednesday Morning SE 5 - 15
Wednesday Afternoon ESE 5 - 15
Wednesday Night SSE 5 - 15
Thursday Morning SSE 5 - 15
Thursday Afternoon S 5 - 15
Thursday Night SSE 10 - 20
Mt. Baker Elevation
Wednesday Morning E 5 - 15
Wednesday Afternoon E 5 - 15
Wednesday Night ESE 5 - 15
Thursday Morning ESE 5 - 15
Thursday Afternoon SE 5 - 15
Thursday Night SE 10 - 20
Stevens and Snoqualmie Pass Elevation
Wednesday Morning E 10 - 20
Wednesday Afternoon E 10 - 20
Wednesday Night E 10 - 20
Thursday Morning ESE 10 - 20
Thursday Afternoon SE 5 - 15
Thursday Night ESE 10 - 20
Mt. Rainier Elevation
Wednesday Morning --- -
Wednesday Afternoon --- -
Wednesday Night --- -
Thursday Morning --- -
Thursday Afternoon --- -
Thursday Night --- -
Mt. Hood Elevation
Wednesday Morning E 10 - 20
Wednesday Afternoon E 10 - 20
Wednesday Night E 10 - 20
Thursday Morning SE 5 - 15
Thursday Afternoon SSE 5 - 15
Thursday Night ESE 10 - 20
Hurricane Ridge Direction - Speed
Wednesday Morning SE 5 - 15
Wednesday Afternoon ESE 5 - 15
Wednesday Night SSE 5 - 15
Thursday Morning SSE 5 - 15
Thursday Afternoon S 5 - 15
Thursday Night SSE 10 - 20
Mt. Baker Direction - Speed
Wednesday Morning E 5 - 15
Wednesday Afternoon E 5 - 15
Wednesday Night ESE 5 - 15
Thursday Morning ESE 5 - 15
Thursday Afternoon SE 5 - 15
Thursday Night SE 10 - 20
Stevens and Snoqualmie Pass Direction - Speed
Wednesday Morning E 10 - 20
Wednesday Afternoon E 10 - 20
Wednesday Night E 10 - 20
Thursday Morning ESE 10 - 20
Thursday Afternoon SE 5 - 15
Thursday Night ESE 10 - 20
Mt. Rainier Direction - Speed
Wednesday Morning --- -
Wednesday Afternoon --- -
Wednesday Night --- -
Thursday Morning --- -
Thursday Afternoon --- -
Thursday Night --- -
Mt. Hood Direction - Speed
Wednesday Morning E 10 - 20
Wednesday Afternoon E 10 - 20
Wednesday Night E 10 - 20
Thursday Morning SE 5 - 15
Thursday Afternoon SSE 5 - 15
Thursday Night ESE 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
Wednesday Morning VAR 0 - 10 VAR 0 - 10 W 10 - 20 --- - WSW 5 - 15
Wednesday Afternoon SW 5 - 15 SW 5 - 15 WSW 10 - 20 --- - SW 10 - 20
Wednesday Night SSW 10 - 20 SW 10 - 20 S 5 - 15 --- - S 10 - 20
Thursday Morning S 10 - 20 SW 10 - 20 SSE 10 - 20 --- - SW 25 - 35
Thursday Afternoon SSW 10 - 20 S 5 - 15 SW 20 - 30 --- - WSW 20 - 30
Mt. Baker Direction - Speed
Wednesday Morning VAR 0 - 10
Wednesday Afternoon SW 5 - 15
Wednesday Night SSW 10 - 20
Thursday Morning S 10 - 20
Thursday Afternoon SSW 10 - 20
Thursday Night SSW 20 - 30
Washington Pass Direction - Speed
Wednesday Morning VAR 0 - 10
Wednesday Afternoon SW 5 - 15
Wednesday Night SW 10 - 20
Thursday Morning SW 10 - 20
Thursday Afternoon S 5 - 15
Thursday Night SSW 15 - 25
Stevens and Snoqualmie Pass Direction - Speed
Wednesday Morning W 10 - 20
Wednesday Afternoon WSW 10 - 20
Wednesday Night S 5 - 15
Thursday Morning SSE 10 - 20
Thursday Afternoon SW 20 - 30
Thursday Night SSW 25 - 35
Mt. Rainier Direction - Speed
Wednesday Morning --- -
Wednesday Afternoon --- -
Wednesday Night --- -
Thursday Morning --- -
Thursday Afternoon --- -
Thursday Night --- -
Mt. Hood Direction - Speed
Wednesday Morning WSW 5 - 15
Wednesday Afternoon SW 10 - 20
Wednesday Night S 10 - 20
Thursday Morning SW 25 - 35
Thursday Afternoon WSW 20 - 30
Thursday Night SSW 15 - 25

Extended Weather Synopsis for Wednesday night through Wednesday

The aforementioned trough should rotate up from the south on Thursday, bringing light showers to the mountains with an increase in clouds. A more defined but still weak frontal system will swing through on Friday from an upper low off meandering toward the PNW coast, bringing a bit heavier rain and snow. Snow levels will cool somewhat into Friday, but are still mild by January standards. The upper low will move inland on Saturday and showers should decrease during the day. 

Extended Weather

Olympics, Washington Cascades and Mt. Hood Area
Friday Cloudy with occasional light rain and snow showers. Friday Light rain and snow, occasionally moderate volcanoes. Saturday Mostly cloudy with light rain and snow showers decreasing in the afternoon. Cooler.

Extended Snow/Freezing Levels

Mt. Baker Snoqualmie Pass Mt. Hood Easterly Flow *
Friday Snow Level 5500' - 6500' 6000' - 7000' 7000' - 8000' *
Friday Snow Level 5000' - 6000' 5000' - 6000' 5000' - 6000' *
Friday Night Snow Level 6500' - 7500' 6500' - 7500' 6500' - 7500' *
Friday Night Snow Level 3500' - 4500' 3500' - 4500' 3500' - 4500'
Mt. Baker Elevation
Friday Snow Level
5500' - 6500'
(Easterly Flow *)
Friday Snow Level
5000' - 6000'
(Easterly Flow *)
Friday Night Snow Level
6500' - 7500'
(Easterly Flow *)
Friday Night Snow Level
3500' - 4500'
Saturday Snow Level
3000' - 4000'
Snoqualmie Pass Elevation
Friday Snow Level
6000' - 7000'
(Easterly Flow *)
Friday Snow Level
5000' - 6000'
(Easterly Flow *)
Friday Night Snow Level
6500' - 7500'
(Easterly Flow *)
Friday Night Snow Level
3500' - 4500'
Saturday Snow Level
3000' - 4000'
Mt. Hood Elevation
Friday Snow Level
7000' - 8000'
(Easterly Flow *)
Friday Snow Level
5000' - 6000'
(Easterly Flow *)
Friday Night Snow Level
6500' - 7500'
(Easterly Flow *)
Friday Night Snow Level
3500' - 4500'
Saturday Snow Level
3000' - 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.

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

Previous forecast from Jan 3, 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.

Corrected Freezing/Snow levels at 11:20AM.