Issued: 1:25 PM PDT Wednesday, March 18, 2020
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 night through Monday

An extended period of high pressure continues. There are subtle changes as the forecast period progresses, but by far the largest changes are diurnal (day to night). Moderate temperature inversions form each night with calm winds and mostly clear skies, making the coldest overnight temperatures (in the 20s) below 4000 ft. The inversions generally mix out by 10 or 11 AM each morning and with dry air and ample sunshine, this change can occur quite rapidly. 

An upper-level ridge continues moving into the region from the NW, bringing warmer sinking air aloft to the region Wednesday night through Thursday. A closed low pressure drops southward offshore and bypasses the region. We're expecting very minimal cloud cover associated with it, but it should switch low-level winds to light easterly for Thursday and Thursday night before it exits the sphere of influence. Some scattered afternoon cumulus clouds are possible Thursday and Friday afternoons. There should be a very subtle overall temperature increase over the time period. Subtle shifts in flow direction and speed will influence the strength and depth of overnight inversions.

Freezing levels should remain above normal for this time of year in the 4000-6000 ft range with little difference N-S or E-W.

Weather Forecast

Hurricane Ridge
Wednesday Night Mostly clear and mild above 4000 ft with a moderate inversion developing below 4000 ft.
Mt. Baker
Wednesday Night Mostly clear and mild above 4000 ft with a moderate inversion developing below 4000 ft.
Washington Pass and Leavenworth
Wednesday Night Mostly clear and mild above 4000 ft with a moderate inversion developing below 4000 ft.
Stevens and Snoqualmie Pass
Wednesday Night Mostly clear and mild above 4000 ft with a moderate inversion developing below 4000 ft.
Mt. Rainier, Crystal and White Pass
Wednesday Night Mostly clear and mild above 4000 ft with a moderate inversion developing below 4000 ft.
Mt. Hood
Wednesday Night Mostly clear and mild above 4000 ft with a moderate inversion developing below 4000 ft.

Snow/Freezing Level (ft)

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

* 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

Wednesday Night Monday Monday Night Monday
4 pm - 4 am 4 am - 4 pm 4 pm - 4 am 4 am - 4 pm
Hurricane Ridge 0 0 0 0
Mt Baker Ski Area 0 0 0 0
Washington Pass 0 0 0 0
Leavenworth 0 0 0 0
Stevens Pass 0 0 0 0
Snoqualmie Pass 0 0 0 0
Mission Ridge 0 0 0 0
Crystal Mt 0 0 0 0
Paradise 0 0 0 0
White Pass 0 0 0 0
Mt Hood Meadows 0 0 0 0
0 0 0 0
Hurricane Ridge Precipitation Forecast
Wednesday Night 0
Monday 0
Monday Night 0
Monday 0
Mt Baker Ski Area Precipitation Forecast
Wednesday Night 0
Monday 0
Monday Night 0
Monday 0
Washington Pass Precipitation Forecast
Wednesday Night 0
Monday 0
Monday Night 0
Monday 0
Leavenworth Precipitation Forecast
Wednesday Night 0
Monday 0
Monday Night 0
Monday 0
Stevens Pass Precipitation Forecast
Wednesday Night 0
Monday 0
Monday Night 0
Monday 0
Snoqualmie Pass Precipitation Forecast
Wednesday Night 0
Monday 0
Monday Night 0
Monday 0
Mission Ridge Precipitation Forecast
Wednesday Night 0
Monday 0
Monday Night 0
Monday 0
Crystal Mt Precipitation Forecast
Wednesday Night 0
Monday 0
Monday Night 0
Monday 0
Paradise Precipitation Forecast
Wednesday Night 0
Monday 0
Monday Night 0
Monday 0
White Pass Precipitation Forecast
Wednesday Night 0
Monday 0
Monday Night 0
Monday 0
Mt Hood Meadows Precipitation Forecast
Wednesday Night 0
Monday 0
Monday Night 0
Monday 0
Timberline Precipitation Forecast
Wednesday Night 0
Monday 0
Monday Night 0
Monday 0

Free Winds at 5000' (mph)

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

Extended Weather Synopsis for Monday night through Monday

Friday night features more clear, mild, calm high-pressure conditions. On Saturday, the region starts to be influenced by a disturbance dropping SE along the spine of the Canadian Rockies. This should bring light NW flow aloft, partial cloud cover to the mountains of Washington State and a slight chance of rain or snow showers for the west slopes of the Washington Cascades and Olympics. Expect more widespread cloud cover on Sunday as a stronger closed low approaches the region, moving down the British Columbia coastline. Freezing levels should remain above normal for this time of year in the 4000-6000 ft range with Mt. Hood a bit warmer than points further north.

Extended Snow/Freezing Levels

Mt. Baker Snoqualmie Pass Mt. Hood Easterly Flow *
Friday Night Freezing Level 4500' - 5500' 4500' - 6000' 6000' - 7000'
Saturday Freezing Level 4000' - 5000' 4500' - 5500' 5000' - 6000'
Saturday Night Freezing Level 4500' - 5500' 4500' - 5500' 5000' - 6000'
Mt. Baker Elevation
Friday Night Freezing Level
4500' - 5500'
Saturday Freezing Level
4000' - 5000'
Saturday Night Freezing Level
4500' - 5500'
Sunday Freezing Level
3500' - 4500'
Snoqualmie Pass Elevation
Friday Night Freezing Level
4500' - 6000'
Saturday Freezing Level
4500' - 5500'
Saturday Night Freezing Level
4500' - 5500'
Sunday Freezing Level
4000' - 5000'
Mt. Hood Elevation
Friday Night Freezing Level
6000' - 7000'
Saturday Freezing Level
5000' - 6000'
Saturday Night Freezing Level
5000' - 6000'
Sunday Freezing Level
4500' - 6000'

* 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 18, 2020

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