Issued: 7:19 AM PST Thursday, December 26, 2013
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 Thursday & Sunday

The upper level ridge has shifted along the Pacific coast Thursday morning.  Light precipitation from a warm front is brushing the north Cascades with mostly clear conditions further south.  The ridge should build today pushing clouds and precipitation back north and allowing a mostly sunny and mild afternoon.  The cold temperatures seen in the valleys yesterday morning have moderated quite a bit and there is no longer a strong temperature inversion. 

A weak frontal system should approach from the west spreading high clouds inland late tonight.  This system now appears weaker with an open trough forming as it approaches Washington and splitting the front.  Light rain and snow should develop along the west slopes Friday morning.  The period of heaviest rain and snow, along with a cooling trend, should occur Friday evening.  Rain and snow showers should continue Friday night, mainly along the west slopes of the Cascades and Mt. Hood. 

Weather Forecast

Olympics, Washington Cascades near and west of the crest including Stevens, Snoqualmie, and White Passes
Thursday Morning

Mostly cloudy north Cascades with occasional light rain and snow.  Partly cloudy central and south Cascades.  Patchy valley fog.  

Thursday Afternoon

Becoming mostly sunny.  

Thursday Night

Patchy valley fog developing overnight.   High clouds increasing from the west late tonight.  

Friday Morning

Light rain and snow developing Olympics and north Cascades, otherwise cloudy with clouds lowering. 

Friday Afternoon - Friday Evening

Light rain and snow becoming light to moderate rain and snow showers Friday evening.  Cooling trend beginning late afternoon. 

East slopes of the Washington Cascades
Thursday Morning

Mostly cloudy northeast Cascades with occasional light rain and snow near the Cascade crest.  Partly cloudy central and southeast Cascades.  Patchy valley fog.  

Thursday Afternoon

Becoming mostly sunny.  

Thursday Night

Mostly clear with patchy valley fog developing overnight.   

Friday Morning

Cloudy. 

Friday Afternoon - Friday Evening

Light rain and snow developing in the afternoon becoming light rain and snow showers in the evening.  Cooling trend beginning late afternoon. 

Mt. Hood Area
Thursday

Mostly sunny and mild.  

Thursday Night - Friday Morning

Mostly clear.  High clouds increasing from the west late tonight.  

Friday Afternoon - Friday Evening

Light rain and snow becoming light to moderate rain and snow showers Friday evening.  Cooling trend beginning late afternoon. 

Snow/Freezing Level (ft)

Hurricane Ridge Mt. Baker Washington Pass Leavenworth Stevens Pass Snoqualmie Pass Mt. Rainier, Crystal & White Pass Mt. Hood
Thursday Snow Level 8000' ' ' ' ' 8000' ' 9500'
Thursday Night Freezing Level 9500' ' ' ' ' 10000' ' 11000'
Friday Morning Snow Level 5500' ' ' ' ' 4500' ' 6000'
Friday Afternoon Snow Level 5000' ' ' ' ' 4000' ' 4500'
Friday Evening Snow Level 4500' ' ' ' ' 3500' ' 5000'
Hurricane Ridge Elevation
Thursday Snow Level
8000'
Thursday Night Freezing Level
9500'
Friday Morning Snow Level
5500'
Friday Afternoon Snow Level
5000'
Friday Evening Snow Level
4500'
Friday Night Snow Level
3500'
Mt. Baker Elevation
Thursday Snow Level
'
Thursday Night Freezing Level
'
Friday Morning Snow Level
'
Friday Afternoon Snow Level
'
Friday Evening Snow Level
'
Friday Night Snow Level
'
Washington Pass Elevation
Thursday Snow Level
'
Thursday Night Freezing Level
'
Friday Morning Snow Level
'
Friday Afternoon Snow Level
'
Friday Evening Snow Level
'
Friday Night Snow Level
'
Leavenworth Elevation
Thursday Snow Level
'
Thursday Night Freezing Level
'
Friday Morning Snow Level
'
Friday Afternoon Snow Level
'
Friday Evening Snow Level
'
Friday Night Snow Level
'
Stevens Pass Elevation
Thursday Snow Level
'
Thursday Night Freezing Level
'
Friday Morning Snow Level
'
Friday Afternoon Snow Level
'
Friday Evening Snow Level
'
Friday Night Snow Level
'
Snoqualmie Pass Elevation
Thursday Snow Level
8000'
Thursday Night Freezing Level
10000'
Friday Morning Snow Level
4500'
Friday Afternoon Snow Level
4000'
Friday Evening Snow Level
3500'
Friday Night Snow Level
3000'
Mt. Rainier & Crystal Elevation
Thursday Snow Level
'
Thursday Night Freezing Level
'
Friday Morning Snow Level
'
Friday Afternoon Snow Level
'
Friday Evening Snow Level
'
Friday Night Snow Level
'
Mt. Hood Elevation
Thursday Snow Level
9500'
Thursday Night Freezing Level
11000'
Friday Morning Snow Level
6000'
Friday Afternoon Snow Level
4500'
Friday Evening Snow Level
5000'
Friday Night 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

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

Free Winds at 5000' (mph)

Hurricane Ridge Mt. Baker Stevens to Snoqualmie Pass Mt. Rainier Mt. Hood
Thursday - Thursday Night SW 5 - 15 --- - SW 5 - 15 --- - SW 5 - 15
Friday SW 10 - 20 --- - SW 10 - 20 --- - WSW 15 - 25
Hurricane Ridge Elevation
Thursday - Thursday Night SW 5 - 15
Friday SW 10 - 20
Friday Night WNW 5 - 15
Mt. Baker Elevation
Thursday - Thursday Night --- -
Friday --- -
Friday Night --- -
Stevens and Snoqualmie Pass Elevation
Thursday - Thursday Night SW 5 - 15
Friday SW 10 - 20
Friday Night WNW 5 - 15
Mt. Rainier Elevation
Thursday - Thursday Night --- -
Friday --- -
Friday Night --- -
Mt. Hood Elevation
Thursday - Thursday Night SW 5 - 15
Friday WSW 15 - 25
Friday Night WNW 5 - 15
Hurricane Ridge Direction - Speed
Thursday - Thursday Night SW 5 - 15
Friday SW 10 - 20
Friday Night WNW 5 - 15
Mt. Baker Direction - Speed
Thursday - Thursday Night --- -
Friday --- -
Friday Night --- -
Stevens and Snoqualmie Pass Direction - Speed
Thursday - Thursday Night SW 5 - 15
Friday SW 10 - 20
Friday Night WNW 5 - 15
Mt. Rainier Direction - Speed
Thursday - Thursday Night --- -
Friday --- -
Friday Night --- -
Mt. Hood Direction - Speed
Thursday - Thursday Night SW 5 - 15
Friday WSW 15 - 25
Friday Night WNW 5 - 15

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
Thursday Morning --- - --- - W 20 - 30 --- - WNW 15 - 25
Thursday Afternoon - Thursday Evening --- - --- - W 25 - 40 --- - W 15 - 30
Thursday Night - Friday Morning --- - --- - SW 25 - 35 --- - SW 25 - 35
Friday Afternoon --- - --- - W 20 - 30 --- - W 30 - 40
Mt. Baker Direction - Speed
Thursday Morning --- -
Thursday Afternoon - Thursday Evening --- -
Thursday Night - Friday Morning --- -
Friday Afternoon --- -
Friday Night --- -
Washington Pass Direction - Speed
Thursday Morning --- -
Thursday Afternoon - Thursday Evening --- -
Thursday Night - Friday Morning --- -
Friday Afternoon --- -
Friday Night --- -
Stevens and Snoqualmie Pass Direction - Speed
Thursday Morning W 20 - 30
Thursday Afternoon - Thursday Evening W 25 - 40
Thursday Night - Friday Morning SW 25 - 35
Friday Afternoon W 20 - 30
Friday Night NW 25 - 40
Mt. Rainier Direction - Speed
Thursday Morning --- -
Thursday Afternoon - Thursday Evening --- -
Thursday Night - Friday Morning --- -
Friday Afternoon --- -
Friday Night --- -
Mt. Hood Direction - Speed
Thursday Morning WNW 15 - 25
Thursday Afternoon - Thursday Evening W 15 - 30
Thursday Night - Friday Morning SW 25 - 35
Friday Afternoon W 30 - 40
Friday Night NW 25 - 40

Extended Weather Synopsis for Sunday night through Sunday

The upper level ridge should rebuild offshore over the weekend.   Light showers should continue along the west slopes on Saturday with little additional accumulation but snow levels should remain cool.  A slight warming trend should occur Sunday and Monday.  Light warm frontal precipitation may brush the Olympics and north Cascades Saturday night and Sunday with more widespread light precipitation moving into the region on Monday. 

If you are interested in how this winter is faring historically, the Office of Washington State Climatologist has a nice graphing tool where you can compare your favorite mountain sites, many of them now NWAC stations, and view the current snowdepth against climatology and/or the ENSO state.  This is an ENSO neutral year, and you can see how we are stacking up against other neutral years (not well). http://www.climate.washington.edu/snowdepth/

 

Extended Weather

Washington Cascades near and west of the crest including Stevens, Snoqualmie, and White Passes and Mt. Hood Area
Saturday

Mostly cloudy with light rain and snow showers, mainly west slopes, tapering off in the afternoon.  

Saturday Night - Sunday

Occasional light rain and snow Olympics and north Cascades.   Mostly cloudy north, partly cloudy central and south.   

Sunday Night - Monday

Cloudy with light rain and snow developing Sunday night. 

Extended Snow/Freezing Levels

Mt. Baker Snoqualmie Pass Mt. Hood Easterly Flow *
Saturday - Saturday Night Snow Level ' - ' 2000' - 3000' 3500' - 5000'
Mt. Baker Elevation
Saturday - Saturday Night Snow Level
' - '
Sunday - Monday Snow Level
' - '
Snoqualmie Pass Elevation
Saturday - Saturday Night Snow Level
2000' - 3000'
Sunday - Monday Snow Level
3500' - 5000'
Mt. Hood Elevation
Saturday - Saturday Night Snow Level
3500' - 5000'
Sunday - Monday Snow Level
5000' - 6500'

* 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 Dec 25, 2013

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.