Issued: 8:11 PM PST Friday, March 9, 2018
by Robert Hahn

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

A shortwave trough has passed east of the Cascades, bringing a cool airmass which is very weakly unstable. Cumulus clouds will remain banked up against the west slopes of the Cascades this afternoon where isolated snow shower is possible, but most precipitation has ended. East of the Cascade Crest, skies are clearing.

A growing ridge Friday through Friday night will become a large-scale and high-amplitude feature on Saturday, sliding slightly eastward, with a high amplitude trough deepening south of Alaska. 

The freezing levels will be above crest level by Saturday afternoon. A very weak shortwave will pass over the top of the ridge Saturday night with little influence on the overall trend of ridge amplification and fair, unseasonably warm weather trending warmer as the weekend progresses. Easterly flow will prevail throughout this period with moderate winds through the passes.

Weather Forecast

Olympics
Friday Partly cloudy.
Friday Night Becoming mostly clear.
Saturday Mostly sunny with a warming trend.
Washington Cascades near and west of the Crest including Stevens, Snoqualmie and White Passes
Friday Mostly cloudy with a chance of isolated snow flurries.
Friday Night Becoming mostly clear.
Saturday Mostly sunny with a warming trend. Light to moderate easterly flow developing. Warming trend.
East Slopes of the Washington Cascades
Friday Cloudy in the morning with a chance of light snow in convergence, becoming partly cloudy by afternoon.
Friday Night Mostly clear and cold.
Saturday Mostly sunny. Moderate east winds.
Mt. Hood
Friday Light snow showers decreasing in the morning. Becoming mostly cloudy during the afternoon.
Friday Night Mostly clear.
Saturday Mostly sunny with a few clouds. Major warming trend.

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 2500' 1500' 0' ' ' 1000' ' 2000'
Friday Night Freezing Level 2500' 1500' 1000' ' ' 2000' ' 3000'
Saturday Morning Freezing Level * 3500' 2500' 2000' ' ' 3000' ' 4000'
Saturday Afternoon Freezing Level * 6000' 5500' 3500' ' ' 6000' ' 6500'
Hurricane Ridge Elevation
Friday Afternoon Snow Level
2500'
Friday Night Freezing Level
2500'
Saturday Morning Freezing Level
3500'
(Easterly Flow *)
Saturday Afternoon Freezing Level
6000'
(Easterly Flow *)
Saturday Night Freezing Level
6500'
(Easterly Flow *)
Mt. Baker Elevation
Friday Afternoon Snow Level
1500'
Friday Night Freezing Level
1500'
Saturday Morning Freezing Level
2500'
(Easterly Flow *)
Saturday Afternoon Freezing Level
5500'
(Easterly Flow *)
Saturday Night Freezing Level
6000'
(Easterly Flow *)
Washington Pass Elevation
Friday Afternoon Snow Level
0'
Friday Night Freezing Level
1000'
Saturday Morning Freezing Level
2000'
(Easterly Flow *)
Saturday Afternoon Freezing Level
3500'
(Easterly Flow *)
Saturday Night Freezing Level
4500'
(Easterly Flow *)
Leavenworth Elevation
Friday Afternoon Snow Level
'
Friday Night Freezing Level
'
Saturday Morning Freezing Level
'
(Easterly Flow *)
Saturday Afternoon Freezing Level
'
(Easterly Flow *)
Saturday Night Freezing Level
'
(Easterly Flow *)
Stevens Pass Elevation
Friday Afternoon Snow Level
'
Friday Night Freezing Level
'
Saturday Morning Freezing Level
'
(Easterly Flow *)
Saturday Afternoon Freezing Level
'
(Easterly Flow *)
Saturday Night Freezing Level
'
(Easterly Flow *)
Snoqualmie Pass Elevation
Friday Afternoon Snow Level
1000'
Friday Night Freezing Level
2000'
Saturday Morning Freezing Level
3000'
(Easterly Flow *)
Saturday Afternoon Freezing Level
6000'
(Easterly Flow *)
Saturday Night Freezing Level
6500'
(Easterly Flow *)
Mt. Rainier & Crystal Elevation
Friday Afternoon Snow Level
'
Friday Night Freezing Level
'
Saturday Morning Freezing Level
'
(Easterly Flow *)
Saturday Afternoon Freezing Level
'
(Easterly Flow *)
Saturday Night Freezing Level
'
(Easterly Flow *)
Mt. Hood Elevation
Friday Afternoon Snow Level
2000'
Friday Night Freezing Level
3000'
Saturday Morning Freezing Level
4000'
(Easterly Flow *)
Saturday Afternoon Freezing Level
6500'
(Easterly Flow *)
Saturday Night Freezing Level
7000'
(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 0.10 LT 0.10
Mt Baker Ski Area LT 0.10 LT 0.10
Washington Pass LT 0.10 LT 0.10
Stevens Pass LT 0.25 LT 0.10
Snoqualmie Pass LT 0.25 LT 0.10
Mission Ridge LT 0.10 LT 0.10
Crystal Mt LT 0.10 LT 0.10
Paradise LT 0.10 LT 0.10
White Pass LT 0.10 LT 0.10
Mt Hood Meadows LT 0.25 LT 0.10
LT 0.25 LT 0.10

Free Winds at 5000' (mph)

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

Extended Weather Synopsis for Tuesday night through Tuesday

On Sunday and Sunday night, the ridge and offshore trough will further amplify. Very warm temperatures are expected across the forecast region.

A significant difference in temperature will develop across the Cascades on Sunday night with temperatures up to 10 F colder east of the Cascade Crest driving moderate easterly flow.

On Monday, an open trough approaches the Pacific Northwest as the ridge slowly moves east.

On Monday night, precipitation enters our coastal waters.

On Tuesday, warm but generally light rain and high elevation snow will arrive on a cooling trend with southerly flow.

Extended Weather

Olympics, Washington Cascades and Mt. Hood Area
Sunday Fair weather, clear skies and unseasonably warm temperatures. Moderate easterly flow through the passes. Monday Fair weather, clear skies and unseasonably warm temperatures. Moderate easterly flow through the passes. High clouds arriving Monday night, lowering and thickening. Tuesday Periods of light to occasionally moderate rain and high elevation snowfall.

Extended Snow/Freezing Levels

Mt. Baker Snoqualmie Pass Mt. Hood Easterly Flow *
Sunday Freezing Level 6500' - 7500' 7000' - 8000' 7500' - 8500'
Sunday Night Freezing Level 7500' - 8500' 7500' - 8500' 8000' - 9000'
Monday Freezing Level 8000' - 9000' 8000' - 9000' 8000' - 9000'
Monday Night Freezing Level 7500' - 8500' 7500' - 8500' 7500' - 8500'
Mt. Baker Elevation
Sunday Freezing Level
6500' - 7500'
Sunday Night Freezing Level
7500' - 8500'
Monday Freezing Level
8000' - 9000'
Monday Night Freezing Level
7500' - 8500'
Tuesday Snow Level
4500' - 6500'
Snoqualmie Pass Elevation
Sunday Freezing Level
7000' - 8000'
Sunday Night Freezing Level
7500' - 8500'
Monday Freezing Level
8000' - 9000'
Monday Night Freezing Level
7500' - 8500'
Tuesday Snow Level
4000' - 6000'
Mt. Hood Elevation
Sunday Freezing Level
7500' - 8500'
Sunday Night Freezing Level
8000' - 9000'
Monday Freezing Level
8000' - 9000'
Monday Night Freezing Level
7500' - 8500'
Tuesday Snow Level
4000' - 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 Mar 9, 2018

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