Issued: 3:13 PM PST Friday, January 12, 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 Friday & Tuesday

After our significant storm system on Thursday produced 1 to 2+ feet of snow in the Olympics and Washington Cascades, post-frontal rain and snow showers followed Friday with moderate westerly winds. Snow levels are hovering in the 4000-5000 ft range on Friday with no significant temperature trend expected. Showers should taper down in the afternoon.

Upper level ridging is attempting to build offshore today, but warm frontal clouds and precipitation slipping under the dirty ridge will quickly move over the area this afternoon and Friday night, keeping light precipitation ongoing overnight, especially for the Olympics and the west slopes of the Cascades. The upper level ridge axis will shift over the Cascades on Saturday and amplify, shunting clouds and light precipitation to our north. A clearing trend is expected on Saturday from south to north, with more afternoon sunshine expected for Mt. Hood and the south Washington Cascades and more lingering cloud cover closer to the Canadian border and a mix in-between.  Snow/freezing levels will rise rapidly on Saturday as a warmer air mass builds over the region. 

The clearing trend will continue Saturday night with continued mild and dry conditions. 

Weather Forecast

Olympics
Friday Cloudy with light rain and snow showers decreasing in the afternoon.
Friday Night Light rain and snow. Warming trend.
Saturday Cloudy with light rain and snow in the morning. Rain ending mid-day and becoming partly to mostly cloudy in the afternoon. Mild.
Washington Cascades near and west of the Crest including Stevens, Snoqualmie and White Passes
Friday Cloudy with light to occasionally moderate rain and snow showers decreasing in the afternoon. Moderate W-SW ridgetop winds.
Friday Night Light rain and snow.
Saturday Cloudy with light rain and snow in the morning, occasionally north and central Cascades. Rain ending mid-day with clearing skies south and central Cascades and becoming mostly cloudy north Cascades in the afternoon. Warming trend.
East Slopes of the Washington Cascades
Friday Cloudy with light rain and snow showers decreasing in the afternoon. Moderate W-SW ridgetop winds.
Friday Night Cloudy with periods of light rain and snow.
Saturday Cloudy with periods of light rain and snow in the morning. Rain ending late morning with clearing skies southeast and central-east Cascades and becoming partly to mostly cloudy northeast Cascades in the afternoon. Warming trend.
Mt. Hood
Friday Cloudy with light to occasionally moderate rain and snow showers decreasing in the afternoon. Winds decreasing slightly in the afternoon.
Friday Night Cloudy with periods of light rain and snow. Warming trend.
Saturday Mostly cloudy with periods of light rain and snow in the morning, becoming mostly sunny in the afternoon. Mild.

Snow/Freezing Level (ft)

Hurricane Ridge Mt. Baker Washington Pass Leavenworth Stevens Pass Snoqualmie Pass Mt. Rainier, Crystal & White Pass Mt. Hood
Friday Afternoon Snow Level 4500' 4500' 4500' ' ' 4500' ' 4500'
Friday Night Snow Level 6000' 4000' 4000' ' ' 4500' ' 6000'
Saturday Morning Snow Level 7500' 5500' 5000' ' ' 7000' ' 8000'
Saturday Afternoon Freezing Level 10000' 8500' 7500' ' ' 10000' ' 11000'
Hurricane Ridge Elevation
Friday Afternoon Snow Level
4500'
Friday Night Snow Level
6000'
Saturday Morning Snow Level
7500'
Saturday Afternoon Freezing Level
10000'
Saturday Night Freezing Level
10500'
(Easterly Flow *)
Mt. Baker Elevation
Friday Afternoon Snow Level
4500'
Friday Night Snow Level
4000'
Saturday Morning Snow Level
5500'
Saturday Afternoon Freezing Level
8500'
Saturday Night Freezing Level
10000'
(Easterly Flow *)
Washington Pass Elevation
Friday Afternoon Snow Level
4500'
Friday Night Snow Level
4000'
Saturday Morning Snow Level
5000'
Saturday Afternoon Freezing Level
7500'
Saturday Night Freezing Level
7000'
(Easterly Flow *)
Leavenworth Elevation
Friday Afternoon Snow Level
'
Friday Night Snow Level
'
Saturday Morning Snow Level
'
Saturday Afternoon Freezing Level
'
Saturday Night Freezing Level
'
(Easterly Flow *)
Stevens Pass Elevation
Friday Afternoon Snow Level
'
Friday Night Snow Level
'
Saturday Morning Snow Level
'
Saturday Afternoon Freezing Level
'
Saturday Night Freezing Level
'
(Easterly Flow *)
Snoqualmie Pass Elevation
Friday Afternoon Snow Level
4500'
Friday Night Snow Level
4500'
Saturday Morning Snow Level
7000'
Saturday Afternoon Freezing Level
10000'
Saturday Night Freezing Level
9000'
(Easterly Flow *)
Mt. Rainier & Crystal Elevation
Friday Afternoon Snow Level
'
Friday Night Snow Level
'
Saturday Morning Snow Level
'
Saturday Afternoon Freezing Level
'
Saturday Night Freezing Level
'
(Easterly Flow *)
Mt. Hood Elevation
Friday Afternoon Snow Level
4500'
Friday Night Snow Level
6000'
Saturday Morning Snow Level
8000'
Saturday Afternoon Freezing Level
11000'
Saturday Night Freezing Level
11000'
(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

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

Free Winds at 5000' (mph)

Hurricane Ridge Mt. Baker Stevens to Snoqualmie Pass Mt. Rainier Mt. Hood
Friday Afternoon SW 5 - 15 SW 10 - 20 SW 15 - 30 --- - SW 15 - 25
Friday Night SW 15 - 25 S 5 - 15 SW 10 - 20 --- - SW 10 - 20
Saturday Morning SW 5 - 15 SW 5 - 15 WSW 15 - 25 --- - VAR 0 - 10
Saturday Afternoon SSE 0 - 10 S 0 - 10 S 0 - 10 --- - SW 5 - 15
Hurricane Ridge Elevation
Friday Afternoon SW 5 - 15
Friday Night SW 15 - 25
Saturday Morning SW 5 - 15
Saturday Afternoon SSE 0 - 10
Saturday Night SE 0 - 10
Mt. Baker Elevation
Friday Afternoon SW 10 - 20
Friday Night S 5 - 15
Saturday Morning SW 5 - 15
Saturday Afternoon S 0 - 10
Saturday Night ESE 0 - 10
Stevens and Snoqualmie Pass Elevation
Friday Afternoon SW 15 - 30
Friday Night SW 10 - 20
Saturday Morning WSW 15 - 25
Saturday Afternoon S 0 - 10
Saturday Night ESE 5 - 15
Mt. Rainier Elevation
Friday Afternoon --- -
Friday Night --- -
Saturday Morning --- -
Saturday Afternoon --- -
Saturday Night --- -
Mt. Hood Elevation
Friday Afternoon SW 15 - 25
Friday Night SW 10 - 20
Saturday Morning VAR 0 - 10
Saturday Afternoon SW 5 - 15
Saturday Night SE 10 - 20
Hurricane Ridge Direction - Speed
Friday Afternoon SW 5 - 15
Friday Night SW 15 - 25
Saturday Morning SW 5 - 15
Saturday Afternoon SSE 0 - 10
Saturday Night SE 0 - 10
Mt. Baker Direction - Speed
Friday Afternoon SW 10 - 20
Friday Night S 5 - 15
Saturday Morning SW 5 - 15
Saturday Afternoon S 0 - 10
Saturday Night ESE 0 - 10
Stevens and Snoqualmie Pass Direction - Speed
Friday Afternoon SW 15 - 30
Friday Night SW 10 - 20
Saturday Morning WSW 15 - 25
Saturday Afternoon S 0 - 10
Saturday Night ESE 5 - 15
Mt. Rainier Direction - Speed
Friday Afternoon --- -
Friday Night --- -
Saturday Morning --- -
Saturday Afternoon --- -
Saturday Night --- -
Mt. Hood Direction - Speed
Friday Afternoon SW 15 - 25
Friday Night SW 10 - 20
Saturday Morning VAR 0 - 10
Saturday Afternoon SW 5 - 15
Saturday Night SE 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
Friday Afternoon SW 15 - 25 WSW 20 - 30 W 25 - 35 --- - WNW 35 - 45
Friday Night WSW 25 - 35 W 30 - 40 W 30 - 40 --- - WSW 25 - 35
Saturday Morning W 30 - 40 W 30 - 40 W 20 - 30 --- - WSW 15 - 25
Saturday Afternoon WSW 15 - 25 WSW 15 - 25 WSW 10 - 20 --- - SSW 5 - 15
Mt. Baker Direction - Speed
Friday Afternoon SW 15 - 25
Friday Night WSW 25 - 35
Saturday Morning W 30 - 40
Saturday Afternoon WSW 15 - 25
Saturday Night SW 10 - 20
Washington Pass Direction - Speed
Friday Afternoon WSW 20 - 30
Friday Night W 30 - 40
Saturday Morning W 30 - 40
Saturday Afternoon WSW 15 - 25
Saturday Night SW 5 - 15
Stevens and Snoqualmie Pass Direction - Speed
Friday Afternoon W 25 - 35
Friday Night W 30 - 40
Saturday Morning W 20 - 30
Saturday Afternoon WSW 10 - 20
Saturday Night SW 10 - 20
Mt. Rainier Direction - Speed
Friday Afternoon --- -
Friday Night --- -
Saturday Morning --- -
Saturday Afternoon --- -
Saturday Night --- -
Mt. Hood Direction - Speed
Friday Afternoon WNW 35 - 45
Friday Night WSW 25 - 35
Saturday Morning WSW 15 - 25
Saturday Afternoon SSW 5 - 15
Saturday Night S 10 - 20

Extended Weather Synopsis for Tuesday night through Tuesday

The high amplitude upper level ridge over the area will shift into eastern Washington/Idaho on Sunday.  An weak frontal boundary well offshore will not reach the area, leaving the Pacific Northwest with sunny and mild conditions for mid-January with the caveat of somewhat muted temperatures in the Passes due to moderate offshore easterly flow. 

A north-south oriented frontal boundary should reach the coast on Monday morning but struggle to push inland during the day.  Light rain and snow should eventually move inland to the Cascades Monday afternoon or night. The main upper level trough axis should swing through on Tuesday, although forecast models are not in good agreement regarding this feature.

Extended Weather

Olympics, Washington Cascades and Mt. Hood Area
Sunday Sunny and mild. Slightly cooler in the Passes and areas exposed to easterly flow. Mostly clear overnight. Monday Increasing clouds with light rain and snow developing in the Olympics during the morning and spreading to the Cascades in the afternoon and evening and continuing overnight. Tuesday Light to occasionally moderate rain and snow. Cooler.

Extended Snow/Freezing Levels

Mt. Baker Snoqualmie Pass Mt. Hood Easterly Flow *
Sunday Freezing Level 10500' - 11500' 10500' - 11500' 11000' - 12000' *
Sunday Night Freezing Level 9500' - 10500' 9500' - 10500' 10000' - 11000' *
Monday Snow Level 6000' - 7000' 6500' - 7500' 7000' - 8000' *
Monday Night Snow Level 5000' - 6000' 4500' - 5500' 6500' - 7500' *
Mt. Baker Elevation
Sunday Freezing Level
10500' - 11500'
(Easterly Flow *)
Sunday Night Freezing Level
9500' - 10500'
(Easterly Flow *)
Monday Snow Level
6000' - 7000'
(Easterly Flow *)
Monday Night Snow Level
5000' - 6000'
(Easterly Flow *)
Tuesday Snow Level
3500' - 4500'
Snoqualmie Pass Elevation
Sunday Freezing Level
10500' - 11500'
(Easterly Flow *)
Sunday Night Freezing Level
9500' - 10500'
(Easterly Flow *)
Monday Snow Level
6500' - 7500'
(Easterly Flow *)
Monday Night Snow Level
4500' - 5500'
(Easterly Flow *)
Tuesday Snow Level
3500' - 4500'
Mt. Hood Elevation
Sunday Freezing Level
11000' - 12000'
(Easterly Flow *)
Sunday Night Freezing Level
10000' - 11000'
(Easterly Flow *)
Monday Snow Level
7000' - 8000'
(Easterly Flow *)
Monday Night Snow Level
6500' - 7500'
(Easterly Flow *)
Tuesday Snow Level
3500' - 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.

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, 2018

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