Issued: 3:19 PM PST Wednesday, December 6, 2017
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 Wednesday & Saturday

The story of the week is high, HIGH pressure with no end in sight at the moment. If this were July, we'd be looking at high temperatures in the mid-80's in the lowlands! In December, we have a nice inversion sitting over us with a shallow cold pool east of the Cascade crest, so don't expect record temperatures in the lowlands. Generally, free air freezing levels will be in the 10,000-12,000 ft range during the short-term forecasting period. The easterly flow will keep the pass-level temperatures much cooler than the free air temperatures seen west of the Cascade crest.

With continued amplification of the ridge on Wednesday and the ridge axis offshore, we'll see northerly flow aloft and moderate easterly offshore flow at the surface. During the day on Thursday, the ridge axis will slightly shift east over us with light and variable winds aloft with offshore easterly gradients peaking Thursday morning.

Weather Forecast

Olympics, Washington Cascades and Mt. Hood Area
Wednesday

Mostly sunny, with morning low clouds possible near passes and valleys.

Wednesday Night

Mostly clear, with low clouds possible near passes and valleys.

Thursday

Mostly sunny, with morning  low clouds possible near passes and valleys.

Snow/Freezing Level (ft)

Hurricane Ridge Mt. Baker Washington Pass Leavenworth Stevens Pass Snoqualmie Pass Mt. Rainier, Crystal & White Pass Mt. Hood
Wednesday Afternoon Freezing Level * 11000' 10000' 8000' ' ' 9000' ' 11000'
Wednesday Night Freezing Level * 11000' 11000' 10000' ' ' 11000' ' 11500'
Thursday Morning Freezing Level * 11000' 11000' 11000' ' ' 11000' ' 11500'
Thursday Afternoon Freezing Level * 11000' 11000' 11000' ' ' 11500' ' 12000'
Hurricane Ridge Elevation
Wednesday Afternoon Freezing Level
11000'
(Easterly Flow *)
Wednesday Night Freezing Level
11000'
(Easterly Flow *)
Thursday Morning Freezing Level
11000'
(Easterly Flow *)
Thursday Afternoon Freezing Level
11000'
(Easterly Flow *)
Thursday Night Freezing Level
10000'
(Easterly Flow *)
Mt. Baker Elevation
Wednesday Afternoon Freezing Level
10000'
(Easterly Flow *)
Wednesday Night Freezing Level
11000'
(Easterly Flow *)
Thursday Morning Freezing Level
11000'
(Easterly Flow *)
Thursday Afternoon Freezing Level
11000'
(Easterly Flow *)
Thursday Night Freezing Level
10000'
(Easterly Flow *)
Washington Pass Elevation
Wednesday Afternoon Freezing Level
8000'
(Easterly Flow *)
Wednesday Night Freezing Level
10000'
(Easterly Flow *)
Thursday Morning Freezing Level
11000'
(Easterly Flow *)
Thursday Afternoon Freezing Level
11000'
(Easterly Flow *)
Thursday Night Freezing Level
10000'
(Easterly Flow *)
Leavenworth Elevation
Wednesday Afternoon Freezing Level
'
(Easterly Flow *)
Wednesday Night Freezing Level
'
(Easterly Flow *)
Thursday Morning Freezing Level
'
(Easterly Flow *)
Thursday Afternoon Freezing Level
'
(Easterly Flow *)
Thursday Night Freezing Level
'
(Easterly Flow *)
Stevens Pass Elevation
Wednesday Afternoon Freezing Level
'
(Easterly Flow *)
Wednesday Night Freezing Level
'
(Easterly Flow *)
Thursday Morning Freezing Level
'
(Easterly Flow *)
Thursday Afternoon Freezing Level
'
(Easterly Flow *)
Thursday Night Freezing Level
'
(Easterly Flow *)
Snoqualmie Pass Elevation
Wednesday Afternoon Freezing Level
9000'
(Easterly Flow *)
Wednesday Night Freezing Level
11000'
(Easterly Flow *)
Thursday Morning Freezing Level
11000'
(Easterly Flow *)
Thursday Afternoon Freezing Level
11500'
(Easterly Flow *)
Thursday Night Freezing Level
10000'
(Easterly Flow *)
Mt. Rainier & Crystal Elevation
Wednesday Afternoon Freezing Level
'
(Easterly Flow *)
Wednesday Night Freezing Level
'
(Easterly Flow *)
Thursday Morning Freezing Level
'
(Easterly Flow *)
Thursday Afternoon Freezing Level
'
(Easterly Flow *)
Thursday Night Freezing Level
'
(Easterly Flow *)
Mt. Hood Elevation
Wednesday Afternoon Freezing Level
11000'
(Easterly Flow *)
Wednesday Night Freezing Level
11500'
(Easterly Flow *)
Thursday Morning Freezing Level
11500'
(Easterly Flow *)
Thursday Afternoon Freezing Level
12000'
(Easterly Flow *)
Thursday Night Freezing Level
10500'
(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 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 0.10 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 0.10
Paradise LT 0.10 LT 0.10
White Pass LT 0.10 LT 0.10
Mt Hood Meadows LT 0.10 LT 0.10
LT 0.10 LT 0.10

Free Winds at 5000' (mph)

Hurricane Ridge Mt. Baker Stevens to Snoqualmie Pass Mt. Rainier Mt. Hood
Wednesday Afternoon ESE 5 - 15 E 0 - 10 E 10 - 20 --- - ESE 15 - 25
Wednesday Night SE 5 - 15 E 0 - 10 ESE 10 - 20 --- - SE 15 - 25
Thursday Morning SE 5 - 15 E 0 - 10 ESE 10 - 20 --- - SE 10 - 20
Thursday Afternoon S 0 - 10 SE 0 - 10 ESE 5 - 15 --- - SE 5 - 15
Hurricane Ridge Elevation
Wednesday Afternoon ESE 5 - 15
Wednesday Night SE 5 - 15
Thursday Morning SE 5 - 15
Thursday Afternoon S 0 - 10
Thursday Night SW 0 - 10
Mt. Baker Elevation
Wednesday Afternoon E 0 - 10
Wednesday Night E 0 - 10
Thursday Morning E 0 - 10
Thursday Afternoon SE 0 - 10
Thursday Night SW 0 - 10
Stevens and Snoqualmie Pass Elevation
Wednesday Afternoon E 10 - 20
Wednesday Night ESE 10 - 20
Thursday Morning ESE 10 - 20
Thursday Afternoon ESE 5 - 15
Thursday Night VAR 0 - 10
Mt. Rainier Elevation
Wednesday Afternoon --- -
Wednesday Night --- -
Thursday Morning --- -
Thursday Afternoon --- -
Thursday Night --- -
Mt. Hood Elevation
Wednesday Afternoon ESE 15 - 25
Wednesday Night SE 15 - 25
Thursday Morning SE 10 - 20
Thursday Afternoon SE 5 - 15
Thursday Night SSE 5 - 15
Hurricane Ridge Direction - Speed
Wednesday Afternoon ESE 5 - 15
Wednesday Night SE 5 - 15
Thursday Morning SE 5 - 15
Thursday Afternoon S 0 - 10
Thursday Night SW 0 - 10
Mt. Baker Direction - Speed
Wednesday Afternoon E 0 - 10
Wednesday Night E 0 - 10
Thursday Morning E 0 - 10
Thursday Afternoon SE 0 - 10
Thursday Night SW 0 - 10
Stevens and Snoqualmie Pass Direction - Speed
Wednesday Afternoon E 10 - 20
Wednesday Night ESE 10 - 20
Thursday Morning ESE 10 - 20
Thursday Afternoon ESE 5 - 15
Thursday Night VAR 0 - 10
Mt. Rainier Direction - Speed
Wednesday Afternoon --- -
Wednesday Night --- -
Thursday Morning --- -
Thursday Afternoon --- -
Thursday Night --- -
Mt. Hood Direction - Speed
Wednesday Afternoon ESE 15 - 25
Wednesday Night SE 15 - 25
Thursday Morning SE 10 - 20
Thursday Afternoon SE 5 - 15
Thursday Night SSE 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 N 5 - 15 N 5 - 15 NE 0 - 10 --- - SE 5 - 15
Wednesday Night E 0 - 10 NE 0 - 10 SE 5 - 15 --- - SE 5 - 15
Thursday Morning SE 0 - 10 VAR 0 - 10 S 0 - 10 --- - S 5 - 15
Thursday Afternoon SSW 0 - 10 SW 0 - 10 SW 5 - 15 --- - SW 5 - 15
Mt. Baker Direction - Speed
Wednesday Afternoon N 5 - 15
Wednesday Night E 0 - 10
Thursday Morning SE 0 - 10
Thursday Afternoon SSW 0 - 10
Thursday Night SW 10 - 20
Washington Pass Direction - Speed
Wednesday Afternoon N 5 - 15
Wednesday Night NE 0 - 10
Thursday Morning VAR 0 - 10
Thursday Afternoon SW 0 - 10
Thursday Night SW 10 - 20
Stevens and Snoqualmie Pass Direction - Speed
Wednesday Afternoon NE 0 - 10
Wednesday Night SE 5 - 15
Thursday Morning S 0 - 10
Thursday Afternoon SW 5 - 15
Thursday Night SW 15 - 25
Mt. Rainier Direction - Speed
Wednesday Afternoon --- -
Wednesday Night --- -
Thursday Morning --- -
Thursday Afternoon --- -
Thursday Night --- -
Mt. Hood Direction - Speed
Wednesday Afternoon SE 5 - 15
Wednesday Night SE 5 - 15
Thursday Morning S 5 - 15
Thursday Afternoon SW 5 - 15
Thursday Night SW 5 - 15

Extended Weather Synopsis for Saturday night through Saturday

On Friday, the ridge is stationary over the Pacific Northwest and British Columbia.  A weak front is stretched out as it approaches the ridge from the west, around 130W. Models differ regarding whether or not moisture reaches the Olympics this weekend. Saturday, the weak front reaches the British Columbia coast line as it flattens the ridge slightly and shifts it east. The influence of the weak front continues into Sunday morning, when the ridge rebounds again to its Thursday/Friday glory. 

Extended Weather

All Zones
Friday

Mostly sunny with periods of high clouds moving across the Washington Cascades and Olympics in the afternoon and increasing slightly overnight.

Saturday

Periods of high and mid-level clouds, especially in the north and west parts of the forecasting region. Slight chance of occasional lowering clouds and light rain in the Olympics. Mostly sunny/clear in the Mt. Hood area. This weather forecast continues Saturday night.

Sunday

Periods of occasional light clouds and precipitation in the Olympics ending in the morning with decreasing periods of high and mid-level clouds in the Cascades. Increasing sunshine from the south to the north everywhere as the day progresses.

Extended Snow/Freezing Levels

Mt. Baker Snoqualmie Pass Mt. Hood Easterly Flow *
Friday Night Freezing Level 9500' - 11500' 10000' - 12000' 10500' - 12500' *
Saturday Freezing Level 8000' - 10000' 9000' - 11000' 10000' - 12000' *
Saturday Night Freezing Level 8000' - 10000' 9500' - 11500' 11000' - 13000' *
Sunday Freezing Level 10000' - 12000' 11000' - 13000' 11500' - 13500' *
Mt. Baker Elevation
Friday Night Freezing Level
9500' - 11500'
(Easterly Flow *)
Saturday Freezing Level
8000' - 10000'
(Easterly Flow *)
Saturday Night Freezing Level
8000' - 10000'
(Easterly Flow *)
Sunday Freezing Level
10000' - 12000'
(Easterly Flow *)
Friday Freezing Level
10000' - 12000'
(Easterly Flow *)
Snoqualmie Pass Elevation
Friday Night Freezing Level
10000' - 12000'
(Easterly Flow *)
Saturday Freezing Level
9000' - 11000'
(Easterly Flow *)
Saturday Night Freezing Level
9500' - 11500'
(Easterly Flow *)
Sunday Freezing Level
11000' - 13000'
(Easterly Flow *)
Friday Freezing Level
10500' - 12500'
(Easterly Flow *)
Mt. Hood Elevation
Friday Night Freezing Level
10500' - 12500'
(Easterly Flow *)
Saturday Freezing Level
10000' - 12000'
(Easterly Flow *)
Saturday Night Freezing Level
11000' - 13000'
(Easterly Flow *)
Sunday Freezing Level
11500' - 13500'
(Easterly Flow *)
Friday Freezing Level
11000' - 13000'
(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 Dec 6, 2017

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