Issued: 2:44 PM PST Wednesday, February 26, 2014
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

An upper level ridge of high pressure extends from the desert southwest north through British Columbia with surface high pressure over Eastern Washington. Strong E to W pressure gradients across the Cascades that had produced moderate easterly winds from Cascade Pass to crest level have begun to ease off on Wednesday afternoon and should weaken further overnight.

This has allowed a few degrees of warming near the passes versus Tuesday.  Mt. Baker, Hurricane and Paradise have poked into the 40s today with intermittent sunshine.  A weak frontal system off the WA/OR coastline is stretching and weakening as it rotates north.  A few showers are possible first for the Mt. Hood and Olympics later today and tonight while the showers have been removed from the forecast elsewhere. An upper level low should be directed into California on Thursday. As the low passes inland on Thursday and it should rotate a more consolidated band of E-W oriented showers mainly into the Mt. Hood region and the south Washington Cascades with the coverage of showers expanding further north.

After peaking Tuesday night through Wednesday morning, snow levels should gradually dip over the next 48 hours.  The exception on Thursday will be on the east side of the Cascades where the cold pool of air, especially over the northeast Cascades should begin to better reflect free-air snow levels seen across the western part of Washington.  

Weather Forecast

Olympics
Wednesday

Partly sunny with increasing clouds in the afternoon. Chance of light rain and snow showers in the afternoon. Continued mild temperatures.   

Washington Cascades near and west of the crest including Stevens, Snoqualmie, and White Passes
Wednesday

Partly sunny with increasing clouds from south to north in the afternoon. Isolated light rain and snow showers mainly south Cascades in the afternoon. Moderate easterly winds near the Cascade Passes decreasing in the afternoon. Continued mild temperatures away from the Cascade Passes.   

Wednesday Night

Partly to mostly cloudy.

Thursday

Partly to mostly cloudy with isolated light rain and snow showers in the afternoon Snoqualmie Pass and north. Mostly cloudy with scattered light to moderate rain and snow showers south and central Washington Cascades.  

East slopes of the Washington Cascades
Wednesday

Partly to mostly sunny with increasing clouds from south to north in the afternoon.

Wednesday Night

Mostly cloudy. Gradual warming. 

Thursday

Mostly cloudy with isolated light rain and snow showers Snoqualmie Pass and northeast Cascades in the afternoon. Scattered light rain and snow showers southeast and central Washington Cascades.  Gradual warming continued. 

Mt. Hood Area
Wednesday

Mostly cloudy with increasing clouds in the afternoon. Isolated light rain and snow showers mainly in the afternoon. Moderate easterly winds decreasing in the afternoon.  Continued temperature inversion due to east winds. 

Wednesday Night - Thursday Morning

Mostly cloudy with scattered light to moderate 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
Wednesday Afternoon - Thursday Morning Snow Level * 6000' ' ' ' ' 5000' ' 6500'
Hurricane Ridge Elevation
Wednesday Afternoon - Thursday Morning Snow Level
6000'
(Easterly Flow *)
Thursday Afternoon - Thursday Night Snow Level
5000'
Mt. Baker Elevation
Wednesday Afternoon - Thursday Morning Snow Level
'
(Easterly Flow *)
Thursday Afternoon - Thursday Night Snow Level
'
Washington Pass Elevation
Wednesday Afternoon - Thursday Morning Snow Level
'
(Easterly Flow *)
Thursday Afternoon - Thursday Night Snow Level
'
Leavenworth Elevation
Wednesday Afternoon - Thursday Morning Snow Level
'
(Easterly Flow *)
Thursday Afternoon - Thursday Night Snow Level
'
Stevens Pass Elevation
Wednesday Afternoon - Thursday Morning Snow Level
'
(Easterly Flow *)
Thursday Afternoon - Thursday Night Snow Level
'
Snoqualmie Pass Elevation
Wednesday Afternoon - Thursday Morning Snow Level
5000'
(Easterly Flow *)
Thursday Afternoon - Thursday Night Snow Level
4500'
Mt. Rainier & Crystal Elevation
Wednesday Afternoon - Thursday Morning Snow Level
'
(Easterly Flow *)
Thursday Afternoon - Thursday Night Snow Level
'
Mt. Hood Elevation
Wednesday Afternoon - Thursday Morning Snow Level
6500'
(Easterly Flow *)
Thursday Afternoon - Thursday Night Snow Level
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.

Precipitation Forecast

Wednesday Wednesday
Hurricane Ridge LT 0.10 LT 0.25
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 0.25
Paradise LT 0.10 LT 0.25
White Pass LT 0.10 LT 0.25
Mt Hood Meadows LT 0.10 0 - 0.50
LT 0.10 0 - 0.50

Free Winds at 5000' (mph)

Hurricane Ridge Mt. Baker Stevens to Snoqualmie Pass Mt. Rainier Mt. Hood
Wednesday Afternoon - Wednesday Evening S 0 - 10 --- - ESE 10 - 20 --- - SSE 5 - 15
Wednesday Night - Thursday Morning S 0 - 10 --- - ESE 5 - 15 --- - S 5 - 15
Hurricane Ridge Elevation
Wednesday Afternoon - Wednesday Evening S 0 - 10
Wednesday Night - Thursday Morning S 0 - 10
Thursday Afternoon - Thursday Night NW 0 - 10
Mt. Baker Elevation
Wednesday Afternoon - Wednesday Evening --- -
Wednesday Night - Thursday Morning --- -
Thursday Afternoon - Thursday Night --- -
Stevens and Snoqualmie Pass Elevation
Wednesday Afternoon - Wednesday Evening ESE 10 - 20
Wednesday Night - Thursday Morning ESE 5 - 15
Thursday Afternoon - Thursday Night NW 5 - 15
Mt. Rainier Elevation
Wednesday Afternoon - Wednesday Evening --- -
Wednesday Night - Thursday Morning --- -
Thursday Afternoon - Thursday Night --- -
Mt. Hood Elevation
Wednesday Afternoon - Wednesday Evening SSE 5 - 15
Wednesday Night - Thursday Morning S 5 - 15
Thursday Afternoon - Thursday Night W 5 - 15
Hurricane Ridge Direction - Speed
Wednesday Afternoon - Wednesday Evening S 0 - 10
Wednesday Night - Thursday Morning S 0 - 10
Thursday Afternoon - Thursday Night NW 0 - 10
Mt. Baker Direction - Speed
Wednesday Afternoon - Wednesday Evening --- -
Wednesday Night - Thursday Morning --- -
Thursday Afternoon - Thursday Night --- -
Stevens and Snoqualmie Pass Direction - Speed
Wednesday Afternoon - Wednesday Evening ESE 10 - 20
Wednesday Night - Thursday Morning ESE 5 - 15
Thursday Afternoon - Thursday Night NW 5 - 15
Mt. Rainier Direction - Speed
Wednesday Afternoon - Wednesday Evening --- -
Wednesday Night - Thursday Morning --- -
Thursday Afternoon - Thursday Night --- -
Mt. Hood Direction - Speed
Wednesday Afternoon - Wednesday Evening SSE 5 - 15
Wednesday Night - Thursday Morning S 5 - 15
Thursday Afternoon - Thursday Night W 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
Wednesday Afternoon - Wednesday Evening --- - --- - S 5 - 15 --- - SW 10 - 20
Wednesday Night - Thursday Mid-day --- - --- - NW 5 - 15 --- - SW 15 - 25
Mt. Baker Direction - Speed
Wednesday Afternoon - Wednesday Evening --- -
Wednesday Night - Thursday Mid-day --- -
Thursday Afternoon - Thursday Night --- -
Washington Pass Direction - Speed
Wednesday Afternoon - Wednesday Evening --- -
Wednesday Night - Thursday Mid-day --- -
Thursday Afternoon - Thursday Night --- -
Stevens and Snoqualmie Pass Direction - Speed
Wednesday Afternoon - Wednesday Evening S 5 - 15
Wednesday Night - Thursday Mid-day NW 5 - 15
Thursday Afternoon - Thursday Night NW 5 - 15
Mt. Rainier Direction - Speed
Wednesday Afternoon - Wednesday Evening --- -
Wednesday Night - Thursday Mid-day --- -
Thursday Afternoon - Thursday Night --- -
Mt. Hood Direction - Speed
Wednesday Afternoon - Wednesday Evening SW 10 - 20
Wednesday Night - Thursday Mid-day SW 15 - 25
Thursday Afternoon - Thursday Night W 5 - 15

Extended Weather Synopsis for Wednesday night through Wednesday

A pattern change should begin to take hold on Friday and continue through the weekend.  An elongated trough of low pressure over central Canada along with strong and cold high pressure will begin to dive south and extend west toward the Pacific coast on Friday.  This should be accompanied with a further decrease in snow levels Friday and perhaps some light upslope showers for the east slopes of the Cascades.  

The details are murky for the weekend but NW flow aloft, weak surface low pressure off the Washington Coast and an upper level low over central BC/AB should all help to draw much colder air into the PNW over the weekend as well as provide enough lift and moisture to keep persistent snow showers in the forecast.  A warm frontal system may start to spread steady precipitation over much of the area by Sunday afternoon. 

Extended Weather

Olympics, Washington Cascades and Mt. Hood Area
Friday

Partly to mostly cloudy with isolated light rain and snow showers, possibly enhanced along the east slopes.  Cooling trend during the day. 

Friday Night

Increasing light to occasionally moderate rain and snow showers overnight.  Cooling trend continues. 

Saturday - Sunday

Light to moderate snow showers. Much colder.  Strong easterly flow developing Saturday through the Cascade Passes. 

Extended Snow/Freezing Levels

Mt. Baker Snoqualmie Pass Mt. Hood Easterly Flow *
Friday Morning Snow Level ' - ' 3500' - 4500' 4000' - 5000' *
Friday Afternoon - Friday Night Snow Level ' - ' 1500' - 2500' 2500' - 4000' *
Mt. Baker Elevation
Friday Morning Snow Level
' - '
(Easterly Flow *)
Friday Afternoon - Friday Night Snow Level
' - '
(Easterly Flow *)
Saturday - Sunday Snow Level
' - '
(Easterly Flow *)
Snoqualmie Pass Elevation
Friday Morning Snow Level
3500' - 4500'
(Easterly Flow *)
Friday Afternoon - Friday Night Snow Level
1500' - 2500'
(Easterly Flow *)
Saturday - Sunday Snow Level
0' - 500'
(Easterly Flow *)
Mt. Hood Elevation
Friday Morning Snow Level
4000' - 5000'
(Easterly Flow *)
Friday Afternoon - Friday Night Snow Level
2500' - 4000'
(Easterly Flow *)
Saturday - Sunday Snow Level
500' - 1500'
(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.

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Previous forecast from Feb 26, 2014

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