Issued: 1:54 PM PST Tuesday, January 12, 2016
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 & Saturday

Afternoon update: Slight adjustments for the Day 1 and 2 precipitation forecasts and to the Mt. Hood 5000 ft winds. 

Warm frontal precipitation has spread inland early this afternoon, extending from a low pressure system off the central British Columbia coast. The frontal band will become N-S oriented with heavier precipitation slowly moving inland late today. Increasing alpine winds and heavier precipitation should begin in the late afternoon for Mt. Hood and the south Washington Cascades and spread northward in the evening and overnight.  

Snow levels will vary across the region with cool easterly flow keeping warmer air to the west at bay for most of the day for the Cascades and Mt. Hood and for the Cascade Passes for much of the Tuesday night.  For the Cascade Passes, warmer air coming in from the S-SW may cause a few hours of mixed precipitation particularly for Snoqualmie and White Pass late tonight.  A switch to westerlies early Wednesday morning should allow a pop-up to free-air snow levels for Snoqualmie and White Pass with rain at pass levels while Stevens may stay all snow. 

The frontal system should split as it passes east of the Cascades later tonight... with a trailing upper level trough off the California coast slowly passing inland Wednesday. This should keep moderate precipitation ongoing for the Snoqualmie Pass down to Mt. Hood through the morning hours.  As the trough moves through the region the air mass should generally cool.  

Weather Forecast

Olympics
Tuesday - Tuesday Evening

Stormy with moderate to occasionally heavy rain and snow. Warming trend through the afternoon. 

Tuesday Night

Light to occasionally moderate rain and snow showers. 

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

Light to occasionally moderate rain and snow, heaviest south Washington Cascades. 

Tuesday Night

Moderate rain and snow, occasionally heavy volcanoes. Chance of mixed precipitation Snoqualmie and White Pass late Tuesday night. 

Wednesday Morning

Light to occasionally moderate rain and snow showers, heaviest south and central Washington Cascades. Brief warming trend Cascade Passes with a switch to westerly winds. 

East slopes of the Washington Cascades
Tuesday Afternoon

Light to occasionally moderate rain and snow. 

Tuesday Night

Light to moderate rain and snow. Chance of mixed precipitation near the Cascade Passes late Tuesday night. 

Wednesday Morning

Light rain and snow showers. Brief warming trend. 

Mt. Hood Area
Tuesday Afternoon - Tuesday Evening

Moderate to occasionally heavy rain and snow, increasing alpine winds. Warming trend.

Tuesday Night - Wednesday Morning

Moderate rain and snow. 

Snow/Freezing Level (ft)

Hurricane Ridge Mt. Baker Washington Pass Leavenworth Stevens Pass Snoqualmie Pass Mt. Rainier, Crystal & White Pass Mt. Hood
Tuesday Afternoon - Tuesday Evening Snow Level * 6500' 4500' 3500' ' ' 3000' ' 7500'
Tuesday Night Snow Level * 5500' 3500' 3000' ' ' 3000' ' 6500'
Wednesday Morning Snow Level 4000' 3500' 3500' ' ' 4500' ' 5500'
Wednesday Afternoon Snow Level 3500' 3500' 3500' ' ' 3500' ' 3000'
Wednesday Night Snow Level 2500' 2500' 1500' ' ' 2500' ' 2500'
Hurricane Ridge Elevation
Tuesday Afternoon - Tuesday Evening Snow Level
6500'
(Easterly Flow *)
Tuesday Night Snow Level
5500'
(Easterly Flow *)
Wednesday Morning Snow Level
4000'
Wednesday Afternoon Snow Level
3500'
Wednesday Night Snow Level
2500'
Tuesday Mid-day Snow Level
6500'
(Easterly Flow *)
Mt. Baker Elevation
Tuesday Afternoon - Tuesday Evening Snow Level
4500'
(Easterly Flow *)
Tuesday Night Snow Level
3500'
(Easterly Flow *)
Wednesday Morning Snow Level
3500'
Wednesday Afternoon Snow Level
3500'
Wednesday Night Snow Level
2500'
Tuesday Mid-day Snow Level
4500'
(Easterly Flow *)
Washington Pass Elevation
Tuesday Afternoon - Tuesday Evening Snow Level
3500'
(Easterly Flow *)
Tuesday Night Snow Level
3000'
(Easterly Flow *)
Wednesday Morning Snow Level
3500'
Wednesday Afternoon Snow Level
3500'
Wednesday Night Snow Level
1500'
Tuesday Mid-day Snow Level
3000'
(Easterly Flow *)
Leavenworth Elevation
Tuesday Afternoon - Tuesday Evening Snow Level
'
(Easterly Flow *)
Tuesday Night Snow Level
'
(Easterly Flow *)
Wednesday Morning Snow Level
'
Wednesday Afternoon Snow Level
'
Wednesday Night Snow Level
'
Tuesday Mid-day Snow Level
'
(Easterly Flow *)
Stevens Pass Elevation
Tuesday Afternoon - Tuesday Evening Snow Level
'
(Easterly Flow *)
Tuesday Night Snow Level
'
(Easterly Flow *)
Wednesday Morning Snow Level
'
Wednesday Afternoon Snow Level
'
Wednesday Night Snow Level
'
Tuesday Mid-day Snow Level
'
(Easterly Flow *)
Snoqualmie Pass Elevation
Tuesday Afternoon - Tuesday Evening Snow Level
3000'
(Easterly Flow *)
Tuesday Night Snow Level
3000'
(Easterly Flow *)
Wednesday Morning Snow Level
4500'
Wednesday Afternoon Snow Level
3500'
Wednesday Night Snow Level
2500'
Tuesday Mid-day Snow Level
3000'
(Easterly Flow *)
Mt. Rainier & Crystal Elevation
Tuesday Afternoon - Tuesday Evening Snow Level
'
(Easterly Flow *)
Tuesday Night Snow Level
'
(Easterly Flow *)
Wednesday Morning Snow Level
'
Wednesday Afternoon Snow Level
'
Wednesday Night Snow Level
'
Tuesday Mid-day Snow Level
'
(Easterly Flow *)
Mt. Hood Elevation
Tuesday Afternoon - Tuesday Evening Snow Level
7500'
(Easterly Flow *)
Tuesday Night Snow Level
6500'
(Easterly Flow *)
Wednesday Morning Snow Level
5500'
Wednesday Afternoon Snow Level
3000'
Wednesday Night Snow Level
2500'
Tuesday Mid-day Snow Level
5000'
(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

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

Free Winds at 5000' (mph)

Hurricane Ridge Mt. Baker Stevens to Snoqualmie Pass Mt. Rainier Mt. Hood
Tuesday Afternoon S 20 - 30 S 10 - 20 SE 15 - 30 --- - S 15 - 25
Tuesday Evening W 15 - 25 SSE 15 - 25 SSE 25 - 35 --- - SW 15 - 25
Tuesday Night - Wednesday Morning W 5 - 15 W 0 - 10 WSW 10 - 20 --- - SW 10 - 20
Wednesday Afternoon W 5 - 15 W 0 - 10 NW 10 - 20 --- - NW 15 - 30
Hurricane Ridge Elevation
Tuesday Afternoon S 20 - 30
Tuesday Evening W 15 - 25
Tuesday Night - Wednesday Morning W 5 - 15
Wednesday Afternoon W 5 - 15
Wednesday Night WSW 10 - 20
Mt. Baker Elevation
Tuesday Afternoon S 10 - 20
Tuesday Evening SSE 15 - 25
Tuesday Night - Wednesday Morning W 0 - 10
Wednesday Afternoon W 0 - 10
Wednesday Night WSW 5 - 15
Stevens and Snoqualmie Pass Elevation
Tuesday Afternoon SE 15 - 30
Tuesday Evening SSE 25 - 35
Tuesday Night - Wednesday Morning WSW 10 - 20
Wednesday Afternoon NW 10 - 20
Wednesday Night WSW 10 - 20
Mt. Rainier Elevation
Tuesday Afternoon --- -
Tuesday Evening --- -
Tuesday Night - Wednesday Morning --- -
Wednesday Afternoon --- -
Wednesday Night --- -
Mt. Hood Elevation
Tuesday Afternoon S 15 - 25
Tuesday Evening SW 15 - 25
Tuesday Night - Wednesday Morning SW 10 - 20
Wednesday Afternoon NW 15 - 30
Wednesday Night W 15 - 30
Hurricane Ridge Direction - Speed
Tuesday Afternoon S 20 - 30
Tuesday Evening W 15 - 25
Tuesday Night - Wednesday Morning W 5 - 15
Wednesday Afternoon W 5 - 15
Wednesday Night WSW 10 - 20
Mt. Baker Direction - Speed
Tuesday Afternoon S 10 - 20
Tuesday Evening SSE 15 - 25
Tuesday Night - Wednesday Morning W 0 - 10
Wednesday Afternoon W 0 - 10
Wednesday Night WSW 5 - 15
Stevens and Snoqualmie Pass Direction - Speed
Tuesday Afternoon SE 15 - 30
Tuesday Evening SSE 25 - 35
Tuesday Night - Wednesday Morning WSW 10 - 20
Wednesday Afternoon NW 10 - 20
Wednesday Night WSW 10 - 20
Mt. Rainier Direction - Speed
Tuesday Afternoon --- -
Tuesday Evening --- -
Tuesday Night - Wednesday Morning --- -
Wednesday Afternoon --- -
Wednesday Night --- -
Mt. Hood Direction - Speed
Tuesday Afternoon S 15 - 25
Tuesday Evening SW 15 - 25
Tuesday Night - Wednesday Morning SW 10 - 20
Wednesday Afternoon NW 15 - 30
Wednesday Night W 15 - 30

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 S 25 - 35 S 20 - 30 SW 50 - 60 --- - SW 60 - 70
Tuesday Evening SW 40 - 50 SW 30 - 40 SW 50 - 60 --- - SW 50 - 60
Tuesday Night WSW 10 - 20 WSW 15 - 25 WSW 10 - 20 --- - SW 35 - 45
Mt. Baker Direction - Speed
Tuesday Afternoon S 25 - 35
Tuesday Evening SW 40 - 50
Tuesday Night WSW 10 - 20
Wednesday - Wednesday Night W 10 - 20
Washington Pass Direction - Speed
Tuesday Afternoon S 20 - 30
Tuesday Evening SW 30 - 40
Tuesday Night WSW 15 - 25
Wednesday - Wednesday Night W 15 - 25
Stevens and Snoqualmie Pass Direction - Speed
Tuesday Afternoon SW 50 - 60
Tuesday Evening SW 50 - 60
Tuesday Night WSW 10 - 20
Wednesday - Wednesday Night WNW 15 - 25
Mt. Rainier Direction - Speed
Tuesday Afternoon --- -
Tuesday Evening --- -
Tuesday Night --- -
Wednesday - Wednesday Night --- -
Mt. Hood Direction - Speed
Tuesday Afternoon SW 60 - 70
Tuesday Evening SW 50 - 60
Tuesday Night SW 35 - 45
Wednesday - Wednesday Night NW 20 - 30

Extended Weather Synopsis for Saturday night through Saturday

Another frontal system sliding SE will reach the area on Thursday, with light precipitation overspreading southern areas and the Olympics mid-day and eventually lifting north Thursday night.  Precipitation totals look light, except moderate around Mt. Hood. 

An upper level ridge will build offshore Friday, but NW flow aloft should keep clouds banked up along the west slopes Friday with scattered showers. 

The next frontal system in this progressive pattern should reach the coast Friday night and move inland Saturday. This front also looks to be N-S oriented and slightly warmer than the Tuesday system. 

Extended Weather

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

Mostly cloudy with light rain and snow developing Olympics, south Washington Cascades and Mt. Hood mid-day and spreading NE. 

Thursday Night

Light rain and snow becoming light showers overnight. 

Friday

Mostly cloudy with scattered light rain and snow showers mainly near and west of the Cascade crest. 

Friday Night - Saturday

Light to moderate rain and snow developing Olympics Friday night and spreading inland to the Cascades Saturday.  

Extended Snow/Freezing Levels

Mt. Baker Snoqualmie Pass Mt. Hood Easterly Flow *
Thursday - Thursday Night Snow Level 1500' - 2500' 2000' - 3000' 2000' - 3000' *
Friday Snow Level 2500' - 3500' 3500' - 4500' 4000' - 5000'
Mt. Baker Elevation
Thursday - Thursday Night Snow Level
1500' - 2500'
(Easterly Flow *)
Friday Snow Level
2500' - 3500'
Friday Night - Saturday Snow Level
3500' - 4500'
(Easterly Flow *)
Snoqualmie Pass Elevation
Thursday - Thursday Night Snow Level
2000' - 3000'
(Easterly Flow *)
Friday Snow Level
3500' - 4500'
Friday Night - Saturday Snow Level
3000' - 4000'
(Easterly Flow *)
Mt. Hood Elevation
Thursday - Thursday Night Snow Level
2000' - 3000'
(Easterly Flow *)
Friday Snow Level
4000' - 5000'
Friday Night - Saturday Snow Level
5000' - 6000'
(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.

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 12, 2016

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