Issued: 2:24 PM PST Tuesday, January 2, 2018
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 Tuesday & Friday

A pair of weak disturbances will move through the upper level ridge centered over the inland NW over the next 24 hours, temporarily flattening the ridge. The first one passing through today will only bring mid and high level clouds, the second one tonight will bring a chance for some very light showers. Snow/freezing levels will stay mild through the short term and offshore easterly flow will stay in the light to moderate range throughout the short term. Low clouds and cooler temperatures will be seen in the Cascade Passes,  lower elevations along the east slopes of the Cascades and Mt. Hood.  

The ridge will briefly rebuild over the area Wednesday and general cloudiness should decrease during the day.  An open trough rotating up from a previously cut-off low pressure system off the California coast will eject northward Wednesday night, bringing a chance of light showers late Wednesday night to the Mt. Hood area. 

Weather Forecast

Olympics
Tuesday Mostly cloudy with mid and high clouds. Mild.
Tuesday Night Cloudy with periods of very light rain or snow. Mild.
Wednesday Mostly cloudy in the morning becoming partly to mostly sunny in the afternoon. Mild.
Washington Cascades near and west of the Crest including Stevens, Snoqualmie and White Passes
Tuesday Mostly cloudy with mid and high clouds. Low clouds, breezy east winds and cooler temperatures Cascade Passes.
Tuesday Night Cloudy with periods of very light rain or snow. Low clouds, breezy east winds and cooler temperatures Cascade Passes.
Wednesday Mostly cloudy in the morning becoming partly to mostly sunny in the afternoon. Low clouds, breezy east winds and cooler temperatures Cascade Passes.
East Slopes of the Washington Cascades
Tuesday Mostly cloudy with mid and high clouds. Low clouds and cooler temperatures lower slopes.
Tuesday Night Cloudy with periods of very light rain or snow. Low clouds and cooler temperatures lower slopes.
Wednesday Mostly cloudy in the morning becoming partly to mostly sunny in the afternoon. Low clouds and cooler temperatures lower slopes.
Mt. Hood
Tuesday Partly to mostly cloudy with mid and high clouds. Low clouds and cooler temperatures lower slopes.
Tuesday Night Cloudy with periods of very light rain or snow. Low clouds and cooler temperatures lower slopes.
Wednesday Mostly cloudy in the morning becoming partly sunny in the afternoon. Low clouds and cooler temperatures lower slopes.

Snow/Freezing Level (ft)

Hurricane Ridge Mt. Baker Washington Pass Leavenworth Stevens Pass Snoqualmie Pass Mt. Rainier, Crystal & White Pass Mt. Hood
Tuesday Freezing Level * 9500' 9000' 8500' ' ' 9500' ' 10500'
Tuesday Night Snow Level * 6000' 6000' 5000' ' ' 6500' ' 7000'
Wednesday Freezing Level * 9000' 8500' 8000' ' ' 9000' ' 10500'
Hurricane Ridge Elevation
Tuesday Freezing Level
9500'
(Easterly Flow *)
Tuesday Night Snow Level
6000'
(Easterly Flow *)
Wednesday Freezing Level
9000'
(Easterly Flow *)
Wednesday Night Freezing Level
8500'
(Easterly Flow *)
Mt. Baker Elevation
Tuesday Freezing Level
9000'
(Easterly Flow *)
Tuesday Night Snow Level
6000'
(Easterly Flow *)
Wednesday Freezing Level
8500'
(Easterly Flow *)
Wednesday Night Freezing Level
8500'
(Easterly Flow *)
Washington Pass Elevation
Tuesday Freezing Level
8500'
(Easterly Flow *)
Tuesday Night Snow Level
5000'
(Easterly Flow *)
Wednesday Freezing Level
8000'
(Easterly Flow *)
Wednesday Night Freezing Level
8000'
(Easterly Flow *)
Leavenworth Elevation
Tuesday Freezing Level
'
(Easterly Flow *)
Tuesday Night Snow Level
'
(Easterly Flow *)
Wednesday Freezing Level
'
(Easterly Flow *)
Wednesday Night Freezing Level
'
(Easterly Flow *)
Stevens Pass Elevation
Tuesday Freezing Level
'
(Easterly Flow *)
Tuesday Night Snow Level
'
(Easterly Flow *)
Wednesday Freezing Level
'
(Easterly Flow *)
Wednesday Night Freezing Level
'
(Easterly Flow *)
Snoqualmie Pass Elevation
Tuesday Freezing Level
9500'
(Easterly Flow *)
Tuesday Night Snow Level
6500'
(Easterly Flow *)
Wednesday Freezing Level
9000'
(Easterly Flow *)
Wednesday Night Freezing Level
9000'
(Easterly Flow *)
Mt. Rainier & Crystal Elevation
Tuesday Freezing Level
'
(Easterly Flow *)
Tuesday Night Snow Level
'
(Easterly Flow *)
Wednesday Freezing Level
'
(Easterly Flow *)
Wednesday Night Freezing Level
'
(Easterly Flow *)
Mt. Hood Elevation
Tuesday Freezing Level
10500'
(Easterly Flow *)
Tuesday Night Snow Level
7000'
(Easterly Flow *)
Wednesday Freezing Level
10500'
(Easterly Flow *)
Wednesday Night Freezing Level
10500'
(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

Friday Friday
Hurricane Ridge LT 0.10 LT 0.10
Mt Baker Ski Area LT 0.10 LT 0.10
Washington Pass LT 0.10 LT 0.10
Stevens Pass LT 0.10 LT 0.10
Snoqualmie Pass LT 0.10 LT 0.10
Mission Ridge LT 0.10 LT 0.10
Crystal Mt LT 0.10 LT 0.10
Paradise LT 0.10 LT 0.10
White Pass LT 0.10 LT 0.10
Mt Hood Meadows LT 0.10 LT 0.10
LT 0.10 LT 0.10

Free Winds at 5000' (mph)

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

Extended Weather Synopsis for Friday night through Friday

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
Thursday 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 *
Thursday Snow Level 5500' - 6500' 6000' - 7000' 7000' - 8000' *
Thursday Night Snow Level 6500' - 7500' 6500' - 7500' 6500' - 7500' *
Friday Snow Level 5000' - 6000' 5000' - 6000' 5000' - 6000' *
Friday Night Snow Level 3500' - 4500' 3500' - 4500' 3500' - 4500'
Mt. Baker Elevation
Thursday Snow Level
5500' - 6500'
(Easterly Flow *)
Thursday Night Snow Level
6500' - 7500'
(Easterly Flow *)
Friday Snow Level
5000' - 6000'
(Easterly Flow *)
Friday Night Snow Level
3500' - 4500'
Saturday Snow Level
3000' - 4000'
Snoqualmie Pass Elevation
Thursday Snow Level
6000' - 7000'
(Easterly Flow *)
Thursday Night Snow Level
6500' - 7500'
(Easterly Flow *)
Friday Snow Level
5000' - 6000'
(Easterly Flow *)
Friday Night Snow Level
3500' - 4500'
Saturday Snow Level
3000' - 4000'
Mt. Hood Elevation
Thursday Snow Level
7000' - 8000'
(Easterly Flow *)
Thursday Night Snow Level
6500' - 7500'
(Easterly Flow *)
Friday Snow Level
5000' - 6000'
(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 2, 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.