Issued: 8:11 AM PST Wednesday, January 14, 2015
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 Wednesday & Wednesday

A broad area of high pressure over the western US will lead to another mostly sunny and warm day for the most areas except where cool easterly flow causes low clouds and occasional flurries for the lower elevations of the east slopes of the Cascades and near the Cascade Passes on Wednesday. 

A weak system offshore near 135 W will split as it fails to push through the upper level ridge later today. A stronger Pacific frontal system extending from a parent low in the Gulf of Alaska will begin to shift the upper level ridge eastward Wednesday night. Light warm frontal precipitation should spread over the area on Thursday. There is still a fair amount of uncertainty around the timing and precipitation amounts with this system, look for updated numbers in the afternoon mtn weather forecast.   

The front itself should move through Thursday night, leading to moderate to occasionally heavy precipitation along the west slopes. Snow levels will stay relatively moderate throughout the event. Cool easterly flow should lead to initial snow in the Cascade passes along with a period of mixed precipitation before switching to westerlies and free-air snow levels early Friday morning.   

Weather Forecast

Olympics, Washington Cascades near and west of the crest and Mt. Hood area
Wednesday

Mostly sunny and warm. 

Wednesday Night

Mostly clear in the evening, increasing clouds overnight. 

Thursday

Light rain and snow developing becoming occasionally moderate later Thursday afternoon. 

Stevens, Snoqualmie and White Pass
Wednesday

Breezy with areas of low clouds near the Passes, mostly clear and warmer in the alpine. 

Wednesday Night

Partly cloudy with increasing clouds overnight. 

Thursday

Light snow developing Thursday morning and possibly becoming light mixed precipitation by mid-day. 

Thursday Evening

Moderate wintry mix.  

East slopes of the Washington Cascades
Wednesday

Low clouds and occasional flurries along the lower east slopes, mostly sunny and warm in the alpine. 

Wednesday Night

Partly cloudy in the evening, increasing mid and high level clouds overnight. 

Thursday

Light rain and snow developing mid-day Thursday. 

Snow/Freezing Level (ft)

Hurricane Ridge Mt. Baker Washington Pass Leavenworth Stevens Pass Snoqualmie Pass Mt. Rainier, Crystal & White Pass Mt. Hood
Wednesday Freezing Level * 10500' 10000' 10000' ' ' 10500' ' 11000'
Wednesday Night - Thursday Morning Freezing Level * 8000' 7500' 6000' ' ' 6500' ' 8000'
Thursday Mid-day - Thursday Afternoon Snow Level * 5500' 4500' 3500' ' ' 5000' ' 6000'
Thursday Evening Snow Level * 5500' 4500' 3000' ' ' 4500' ' 6500'
Hurricane Ridge Elevation
Wednesday Freezing Level
10500'
(Easterly Flow *)
Wednesday Night - Thursday Morning Freezing Level
8000'
(Easterly Flow *)
Thursday Mid-day - Thursday Afternoon Snow Level
5500'
(Easterly Flow *)
Thursday Evening Snow Level
5500'
(Easterly Flow *)
Thursday Night Snow Level
4500'
Mt. Baker Elevation
Wednesday Freezing Level
10000'
(Easterly Flow *)
Wednesday Night - Thursday Morning Freezing Level
7500'
(Easterly Flow *)
Thursday Mid-day - Thursday Afternoon Snow Level
4500'
(Easterly Flow *)
Thursday Evening Snow Level
4500'
(Easterly Flow *)
Thursday Night Snow Level
4000'
Washington Pass Elevation
Wednesday Freezing Level
10000'
(Easterly Flow *)
Wednesday Night - Thursday Morning Freezing Level
6000'
(Easterly Flow *)
Thursday Mid-day - Thursday Afternoon Snow Level
3500'
(Easterly Flow *)
Thursday Evening Snow Level
3000'
(Easterly Flow *)
Thursday Night Snow Level
3500'
Leavenworth Elevation
Wednesday Freezing Level
'
(Easterly Flow *)
Wednesday Night - Thursday Morning Freezing Level
'
(Easterly Flow *)
Thursday Mid-day - Thursday Afternoon Snow Level
'
(Easterly Flow *)
Thursday Evening Snow Level
'
(Easterly Flow *)
Thursday Night Snow Level
'
Stevens Pass Elevation
Wednesday Freezing Level
'
(Easterly Flow *)
Wednesday Night - Thursday Morning Freezing Level
'
(Easterly Flow *)
Thursday Mid-day - Thursday Afternoon Snow Level
'
(Easterly Flow *)
Thursday Evening Snow Level
'
(Easterly Flow *)
Thursday Night Snow Level
'
Snoqualmie Pass Elevation
Wednesday Freezing Level
10500'
(Easterly Flow *)
Wednesday Night - Thursday Morning Freezing Level
6500'
(Easterly Flow *)
Thursday Mid-day - Thursday Afternoon Snow Level
5000'
(Easterly Flow *)
Thursday Evening Snow Level
4500'
(Easterly Flow *)
Thursday Night Snow Level
5000'
Mt. Rainier & Crystal Elevation
Wednesday Freezing Level
'
(Easterly Flow *)
Wednesday Night - Thursday Morning Freezing Level
'
(Easterly Flow *)
Thursday Mid-day - Thursday Afternoon Snow Level
'
(Easterly Flow *)
Thursday Evening Snow Level
'
(Easterly Flow *)
Thursday Night Snow Level
'
Mt. Hood Elevation
Wednesday Freezing Level
11000'
(Easterly Flow *)
Wednesday Night - Thursday Morning Freezing Level
8000'
(Easterly Flow *)
Thursday Mid-day - Thursday Afternoon Snow Level
6000'
(Easterly Flow *)
Thursday Evening Snow Level
6500'
(Easterly Flow *)
Thursday Night Snow Level
5500'

* 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 0.50 - 0.75
Mt Baker Ski Area LT 0.10 0 - 2.00
Washington Pass LT 0.10 0 - 0.75
Stevens Pass LT 0.10 0 - 0.75
Snoqualmie Pass LT 0.10 0 - 1.00
Mission Ridge LT 0.10 LT 0.25
Crystal Mt LT 0.10 0 - 1.00
Paradise LT 0.10 0 - 1.50
White Pass LT 0.10 0 - 0.75
Mt Hood Meadows LT 0.10 1.00 - 1.50
LT 0.10 0 - 1.50

Free Winds at 5000' (mph)

Hurricane Ridge Mt. Baker Stevens to Snoqualmie Pass Mt. Rainier Mt. Hood
Wednesday S 0 - 10 S 0 - 10 E 0 - 10 --- - E 0 - 10
Wednesday Night - Thursday Morning SW 15 - 25 S 10 - 20 S 10 - 20 --- - SW 10 - 20
Thursday Afternoon - Thursday Evening SSW 30 - 40 SSW 20 - 30 SSW 15 - 30 --- - SW 25 - 40
Hurricane Ridge Elevation
Wednesday S 0 - 10
Wednesday Night - Thursday Morning SW 15 - 25
Thursday Afternoon - Thursday Evening SSW 30 - 40
Thursday Night W 15 - 25
Mt. Baker Elevation
Wednesday S 0 - 10
Wednesday Night - Thursday Morning S 10 - 20
Thursday Afternoon - Thursday Evening SSW 20 - 30
Thursday Night SW 10 - 20
Stevens and Snoqualmie Pass Elevation
Wednesday E 0 - 10
Wednesday Night - Thursday Morning S 10 - 20
Thursday Afternoon - Thursday Evening SSW 15 - 30
Thursday Night W 5 - 15
Mt. Rainier Elevation
Wednesday --- -
Wednesday Night - Thursday Morning --- -
Thursday Afternoon - Thursday Evening --- -
Thursday Night --- -
Mt. Hood Elevation
Wednesday E 0 - 10
Wednesday Night - Thursday Morning SW 10 - 20
Thursday Afternoon - Thursday Evening SW 25 - 40
Thursday Night W 15 - 25
Hurricane Ridge Direction - Speed
Wednesday S 0 - 10
Wednesday Night - Thursday Morning SW 15 - 25
Thursday Afternoon - Thursday Evening SSW 30 - 40
Thursday Night W 15 - 25
Mt. Baker Direction - Speed
Wednesday S 0 - 10
Wednesday Night - Thursday Morning S 10 - 20
Thursday Afternoon - Thursday Evening SSW 20 - 30
Thursday Night SW 10 - 20
Stevens and Snoqualmie Pass Direction - Speed
Wednesday E 0 - 10
Wednesday Night - Thursday Morning S 10 - 20
Thursday Afternoon - Thursday Evening SSW 15 - 30
Thursday Night W 5 - 15
Mt. Rainier Direction - Speed
Wednesday --- -
Wednesday Night - Thursday Morning --- -
Thursday Afternoon - Thursday Evening --- -
Thursday Night --- -
Mt. Hood Direction - Speed
Wednesday E 0 - 10
Wednesday Night - Thursday Morning SW 10 - 20
Thursday Afternoon - Thursday Evening SW 25 - 40
Thursday Night 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
Wednesday S 5 - 15 SW 0 - 10 S 5 - 15 --- - SW 10 - 20
Wednesday Night - Thursday Morning SW 20 - 30 SW 15 - 25 SW 25 - 35 --- - SW 25 - 35
Thursday Afternoon - Thursday Evening SW 35 - 45 SW 30 - 40 SW 45 - 55 --- - SW 45 - 60
Mt. Baker Direction - Speed
Wednesday S 5 - 15
Wednesday Night - Thursday Morning SW 20 - 30
Thursday Afternoon - Thursday Evening SW 35 - 45
Thursday Night W 20 - 30
Washington Pass Direction - Speed
Wednesday SW 0 - 10
Wednesday Night - Thursday Morning SW 15 - 25
Thursday Afternoon - Thursday Evening SW 30 - 40
Thursday Night W 30 - 40
Stevens and Snoqualmie Pass Direction - Speed
Wednesday S 5 - 15
Wednesday Night - Thursday Morning SW 25 - 35
Thursday Afternoon - Thursday Evening SW 45 - 55
Thursday Night WNW 30 - 40
Mt. Rainier Direction - Speed
Wednesday --- -
Wednesday Night - Thursday Morning --- -
Thursday Afternoon - Thursday Evening --- -
Thursday Night --- -
Mt. Hood Direction - Speed
Wednesday SW 10 - 20
Wednesday Night - Thursday Morning SW 25 - 35
Thursday Afternoon - Thursday Evening SW 45 - 60
Thursday Night W 30 - 40

Extended Weather Synopsis for Wednesday night through Wednesday

A transient upper level ridge will quickly build in Friday afternoon, leading to mainly dry weather Friday afternoon through Friday night. Light showers are possible Friday, especially near an area of weak convergence centered around Stevens Pass. 

A wet weekend is in store for the Pacific Northwest. At this point, forecast models indicate an initial wave of warm frontal moisture will mainly affect the Mt. Hood area and the south Washington Cascades Saturday with mild snow levels. Precipitation associated with the cold front should increase for all areas as it approaches the coast Saturday night.  

More significant cooling should follow behind the frontal passage Sunday with showers in westerly flow expected.   

Extended Weather

Olympics, Washington Cascades and Mt. Hood Area
Friday

Mostly cloudy with light rain and snow showers, mainly near Snoqualmie and Stevens Passes. 

Friday Night

Mostly cloudy. 

Saturday

Light rain and snow developing Saturday, except becoming moderate Mt. Hood area

Saturday Night

Moderate rain and snow, occasionally heavy west slopes of the Cascades. 

Sunday

Moderate rain and snow becoming light to moderate showers. Cooling trend. 

Extended Snow/Freezing Levels

Mt. Baker Snoqualmie Pass Mt. Hood Easterly Flow *
Friday - Friday Night Snow Level 2500' - 3500' 3000' - 4000' 4000' - 5000'
Saturday Snow Level 4000' - 5000' 5500' - 6500' 7500' - 8500' *
Saturday Night - Sunday Morning Snow Level 5500' - 6500' 6000' - 7000' 7000' - 8000' *
Mt. Baker Elevation
Friday - Friday Night Snow Level
2500' - 3500'
Saturday Snow Level
4000' - 5000'
(Easterly Flow *)
Saturday Night - Sunday Morning Snow Level
5500' - 6500'
(Easterly Flow *)
Sunday Afternoon Snow Level
3500' - 4500'
Snoqualmie Pass Elevation
Friday - Friday Night Snow Level
3000' - 4000'
Saturday Snow Level
5500' - 6500'
(Easterly Flow *)
Saturday Night - Sunday Morning Snow Level
6000' - 7000'
(Easterly Flow *)
Sunday Afternoon Snow Level
3500' - 4500'
Mt. Hood Elevation
Friday - Friday Night Snow Level
4000' - 5000'
Saturday Snow Level
7500' - 8500'
(Easterly Flow *)
Saturday Night - Sunday Morning Snow Level
7000' - 8000'
(Easterly Flow *)
Sunday Afternoon Snow Level
4000' - 5000'

* 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 9, 2015

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.