Issued: 2:46 PM PST Thursday, January 21, 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 Thursday & Monday

Afternoon update: Lowered Day 1 precipitation forecasts for some locations. 

A Pacific frontal system turned on the moisture tap this morning... with heavier than expected precipitation for the south and central Cascades resulting in up to a foot of snow late Wednesday night through early Thursday morning. However, warm frontal moisture has moved north and the axis of frontal precipitation has stayed west of the central and south Cascades with heavy precipitation continuing for the Olympics and north Cascades. As the frontal boundary shifts east tonight, light rain and snow should increase once again for the central and southern Cascades. 

Snow levels have risen to 6500-8000 feet from north to south from Mt. Baker down to Mt. Hood.  Easterly winds delayed the warming trend in the Cascade Passes, but Snoqualmie Pass did see a period of rain at pass level and of freezing rain that extended up to 5000' locally. The northeast Cascades snow levels should peak Thursday night. 

The front should slowly push through early Friday morning. Post frontal showers should be heaviest near Mt. Baker with showers everywhere tapering off by late afternoon and evening.  A slow cooling trend will ensue during the day Friday. 

A low pressure system around 130 W and off the OR/CA coast Friday afternoon will track inland Friday night. Light rain and snow should develop by daybreak Saturday for Mt. Hood and the south Washington Cascades, while areas further north may only see an increase in mid and high clouds. 

Weather Forecast

Olympics and north Cascades
Thursday - Thursday Evening

Stormy with heavy rain and snow.  Warming trend. 

Thursday Night

Moderate rain and snow. 

Friday

Cloudy with light to moderate rain and snow showers, especially Mt. Baker. Slow cooling trend. 

central and south Washington Cascades near and west of the crest including Stevens, Snoqualmie, and White Passes
Thursday Afternoon

Cloudy with periods of light rain and snow. Mild. 

Thursday Night

Light to occasionally moderate rain and snow. Mild. 

Friday

Cloudy with light to moderate rain and snow showers easing in the afternoon. Slow cooling trend. 

Mt. Hood Area
Thursday - Thursday Night

Cloudy with periods of light rain and snow. Warming trend. 

Friday

Cloudy with light to moderate rain and snow showers easing in the afternoon. Slow cooling trend. 

East slopes of the Washington Cascades
Thursday - Thursday Evening

Stormy with light to moderate rain and snow, occasionally heavy northeast Cascades. Slow warming trend. Freezing rain possible lower east slopes and valleys Thursday morning through mid-day. 

Thursday Night

Light rain and snow.  

Friday

Mostly cloudy with light rain and snow showers easing in the afternoon.  

Snow/Freezing Level (ft)

Hurricane Ridge Mt. Baker Washington Pass Leavenworth Stevens Pass Snoqualmie Pass Mt. Rainier, Crystal & White Pass Mt. Hood
Thursday Afternoon Snow Level * 7500' 6500' 4000' ' ' 6500' ' 8000'
Thursday Night Snow Level * 6500' 6500' 4500' ' ' 7000' ' 7000'
Friday Morning Snow Level 5500' 5000' 4500' ' ' 5000' ' 5500'
Friday Afternoon Snow Level 4500' 4500' 4500' ' ' 4500' ' 6000'
Hurricane Ridge Elevation
Thursday Afternoon Snow Level
7500'
(Easterly Flow *)
Thursday Night Snow Level
6500'
(Easterly Flow *)
Friday Morning Snow Level
5500'
Friday Afternoon Snow Level
4500'
Friday Night Snow Level
4000'
(Easterly Flow *)
Mt. Baker Elevation
Thursday Afternoon Snow Level
6500'
(Easterly Flow *)
Thursday Night Snow Level
6500'
(Easterly Flow *)
Friday Morning Snow Level
5000'
Friday Afternoon Snow Level
4500'
Friday Night Snow Level
3000'
(Easterly Flow *)
Washington Pass Elevation
Thursday Afternoon Snow Level
4000'
(Easterly Flow *)
Thursday Night Snow Level
4500'
(Easterly Flow *)
Friday Morning Snow Level
4500'
Friday Afternoon Snow Level
4500'
Friday Night Snow Level
3000'
(Easterly Flow *)
Leavenworth Elevation
Thursday Afternoon Snow Level
'
(Easterly Flow *)
Thursday Night Snow Level
'
(Easterly Flow *)
Friday Morning Snow Level
'
Friday Afternoon Snow Level
'
Friday Night Snow Level
'
(Easterly Flow *)
Stevens Pass Elevation
Thursday Afternoon Snow Level
'
(Easterly Flow *)
Thursday Night Snow Level
'
(Easterly Flow *)
Friday Morning Snow Level
'
Friday Afternoon Snow Level
'
Friday Night Snow Level
'
(Easterly Flow *)
Snoqualmie Pass Elevation
Thursday Afternoon Snow Level
6500'
(Easterly Flow *)
Thursday Night Snow Level
7000'
(Easterly Flow *)
Friday Morning Snow Level
5000'
Friday Afternoon Snow Level
4500'
Friday Night Snow Level
3000'
(Easterly Flow *)
Mt. Rainier & Crystal Elevation
Thursday Afternoon Snow Level
'
(Easterly Flow *)
Thursday Night Snow Level
'
(Easterly Flow *)
Friday Morning Snow Level
'
Friday Afternoon Snow Level
'
Friday Night Snow Level
'
(Easterly Flow *)
Mt. Hood Elevation
Thursday Afternoon Snow Level
8000'
(Easterly Flow *)
Thursday Night Snow Level
7000'
(Easterly Flow *)
Friday Morning Snow Level
5500'
Friday Afternoon Snow Level
6000'
Friday Night Snow Level
4500'
(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

Monday Monday
Hurricane Ridge 1.00 - 2.00 LT 0.25
Mt Baker Ski Area 4.00 - 6.00 0.75 - 1.00
Washington Pass 1.00 - 1.50 0.25 - 0.50
Stevens Pass 0 - 1.00 0.25 - 0.50
Snoqualmie Pass 1.00 - 1.50 0 - 0.50
Mission Ridge 0 - 0.50 LT 0.25
Crystal Mt 0 - 1.50 0.25 - 0.50
Paradise 1.00 - 1.50 0 - 0.50
White Pass 0.50 - 1.00 0.25 - 0.50
Mt Hood Meadows 0.25 - 0.50 0 - 0.50
0 - 0.50 0.50 - 1.00

Free Winds at 5000' (mph)

Hurricane Ridge Mt. Baker Stevens to Snoqualmie Pass Mt. Rainier Mt. Hood
Thursday Mid-day - Thursday Afternoon SW 30 - 40 S 30 - 40 SSE 20 - 35 --- - SSW 20 - 30
Thursday Night SSW 15 - 25 S 15 - 30 S 20 - 30 --- - S 15 - 30
Friday Morning SW 15 - 25 SW 15 - 25 SW 15 - 25 --- - SW 10 - 20
Friday Afternoon VAR 0 - 10 SW 5 - 15 SW 5 - 15 --- - SE 5 - 15
Hurricane Ridge Elevation
Thursday Mid-day - Thursday Afternoon SW 30 - 40
Thursday Night SSW 15 - 25
Friday Morning SW 15 - 25
Friday Afternoon VAR 0 - 10
Friday Night SE 5 - 15
Mt. Baker Elevation
Thursday Mid-day - Thursday Afternoon S 30 - 40
Thursday Night S 15 - 30
Friday Morning SW 15 - 25
Friday Afternoon SW 5 - 15
Friday Night SE 0 - 10
Stevens and Snoqualmie Pass Elevation
Thursday Mid-day - Thursday Afternoon SSE 20 - 35
Thursday Night S 20 - 30
Friday Morning SW 15 - 25
Friday Afternoon SW 5 - 15
Friday Night ESE 15 - 25
Mt. Rainier Elevation
Thursday Mid-day - Thursday Afternoon --- -
Thursday Night --- -
Friday Morning --- -
Friday Afternoon --- -
Friday Night --- -
Mt. Hood Elevation
Thursday Mid-day - Thursday Afternoon SSW 20 - 30
Thursday Night S 15 - 30
Friday Morning SW 10 - 20
Friday Afternoon SE 5 - 15
Friday Night SSE 15 - 25
Hurricane Ridge Direction - Speed
Thursday Mid-day - Thursday Afternoon SW 30 - 40
Thursday Night SSW 15 - 25
Friday Morning SW 15 - 25
Friday Afternoon VAR 0 - 10
Friday Night SE 5 - 15
Mt. Baker Direction - Speed
Thursday Mid-day - Thursday Afternoon S 30 - 40
Thursday Night S 15 - 30
Friday Morning SW 15 - 25
Friday Afternoon SW 5 - 15
Friday Night SE 0 - 10
Stevens and Snoqualmie Pass Direction - Speed
Thursday Mid-day - Thursday Afternoon SSE 20 - 35
Thursday Night S 20 - 30
Friday Morning SW 15 - 25
Friday Afternoon SW 5 - 15
Friday Night ESE 15 - 25
Mt. Rainier Direction - Speed
Thursday Mid-day - Thursday Afternoon --- -
Thursday Night --- -
Friday Morning --- -
Friday Afternoon --- -
Friday Night --- -
Mt. Hood Direction - Speed
Thursday Mid-day - Thursday Afternoon SSW 20 - 30
Thursday Night S 15 - 30
Friday Morning SW 10 - 20
Friday Afternoon SE 5 - 15
Friday Night SSE 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
Thursday Afternoon - Thursday Evening SW 50 - 60 SW 40 - 50 SW 50 - 60 --- - SW 40 - 55
Thursday Night - Friday Morning SW 35 - 45 SSW 25 - 35 SW 40 - 50 --- - SW 35 - 50
Friday Afternoon SW 10 - 20 W 20 - 30 WSW 15 - 25 --- - SW 10 - 20
Mt. Baker Direction - Speed
Thursday Afternoon - Thursday Evening SW 50 - 60
Thursday Night - Friday Morning SW 35 - 45
Friday Afternoon SW 10 - 20
Friday Night SE 10 - 20
Washington Pass Direction - Speed
Thursday Afternoon - Thursday Evening SW 40 - 50
Thursday Night - Friday Morning SSW 25 - 35
Friday Afternoon W 20 - 30
Friday Night S 15 - 25
Stevens and Snoqualmie Pass Direction - Speed
Thursday Afternoon - Thursday Evening SW 50 - 60
Thursday Night - Friday Morning SW 40 - 50
Friday Afternoon WSW 15 - 25
Friday Night S 15 - 30
Mt. Rainier Direction - Speed
Thursday Afternoon - Thursday Evening --- -
Thursday Night - Friday Morning --- -
Friday Afternoon --- -
Friday Night --- -
Mt. Hood Direction - Speed
Thursday Afternoon - Thursday Evening SW 40 - 55
Thursday Night - Friday Morning SW 35 - 50
Friday Afternoon SW 10 - 20
Friday Night SSW 35 - 45

Extended Weather Synopsis for Monday night through Monday

As the low tracks to the eastern part of Oregon on Saturday, a quick flip to NW flow aloft should produce a period of light to moderate rain and snow showers, heaviest along the west slopes, through early Sunday morning along with a cooling trend. 

A weak front is forecast to stall and break up along the coast Sunday...perhaps only bringing light precipitation to the Olympics.  Monday should be a break between weather systems with only a few lingering mountain showers. 

Extended Weather

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

Light rain and snow, occasionally moderate Mt. Hood and south Washington Cascades. 

Saturday Afternoon - Sunday Morning

Mostly cloudy with light rain and snow showers, except moderate west slopes and Mt. Hood Saturday afternoon and evening. Cooling trend.

Sunday

Cloudy with light rain and snow Olympics, chance of light rain and snow Cascades and Mt. Hood. 

Sunday Night - Monday

Partly to mostly cloudy with isolated rain and snow showers. 

Extended Snow/Freezing Levels

Mt. Baker Snoqualmie Pass Mt. Hood Easterly Flow *
Saturday Snow Level 3000' - 4000' 3000' - 4000' 4000' - 5000'
Saturday Night - Sunday Night Snow Level 2500' - 3500' 2500' - 3500' 2500' - 3500'
Mt. Baker Elevation
Saturday Snow Level
3000' - 4000'
Saturday Night - Sunday Night Snow Level
2500' - 3500'
Sunday Snow Level
4000' - 5000'
Snoqualmie Pass Elevation
Saturday Snow Level
3000' - 4000'
Saturday Night - Sunday Night Snow Level
2500' - 3500'
Sunday Snow Level
4000' - 5500'
Mt. Hood Elevation
Saturday Snow Level
4000' - 5000'
Saturday Night - Sunday Night Snow Level
2500' - 3500'
Sunday Snow Level
4500' - 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.

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 21, 2016

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