Issued: 7:08 AM PDT Tuesday, March 20, 2018
by Robert Hahn

Jump to: Weather Forecast I Snow/Freezing Level I Precipitation I Free Winds 5k I Free Winds 9k

Weather Synopsis for Tuesday & Monday

On Tuesday, a high pressure wedge sits over the region bringing another day of mostly sunny, spring-like weather, with light winds. Expect cool, crisp morning temperatures under virtually cloud-free skies to rebound with the strength of the March sunshine.

A deep trough with an upper low slides S-SE offfshore of the Alaskan panhandle and a closed low drifting NE well off the California Coast will be the major players for the remainder of the week.

Tuesday night, the ridge disappears as the two systems flatten out the wedge and the deep trough subsumes the closed low.

On Wednesday, the subsumed feature with surface low centers moves NE toward our region ahead of the trough, bringing moisture into our region and periods of gradually increasing light rain/snow mainly for the Mt. Hood region and South Cascades during daylight hours. 

On Wednesday night, the surface front associated with the deeply digging trough offshore approaches the near-shore waters with periods of light to moderate rain and snow spread throughout the forecast area. Southerly or S-SE winds will increase into the moderate range.

Temperatures will remain warmer than seasonal norms throughout the short-term forecast period.

Weather Forecast

Olympics
Tuesday A mix of clouds and sun.
Tuesday Night Fair with high cloud cover over most areas keeping surface temperatures relatively warm.
Wednesday High clouds with some sun breaks in the morning, then clouds increasing in the afternoon.
Washington Cascades near and west of the Crest including Stevens, Snoqualmie and White Passes
Tuesday Mostly sunny southern part with a mix of clouds and sun northern part.
Tuesday Night Fair with high cloud cover over most areas keeping surface temperatures relatively warm.
Wednesday Mainly high clouds in the morning with clouds thickening and lowering in the afternoon. Very light rain and snow developing in the afternoon.
East Slopes of the Washington Cascades
Tuesday Mostly sunny southern part with a mix of clouds and sun northern part.
Tuesday Night Fair with high cloud cover over most areas keeping surface temperatures relatively warm.
Wednesday Mainly high clouds in the morning with clouds thickening and lowering in the afternoon. Very light rain and snow possible near the crest during the afternoon.
Mt. Hood
Tuesday Mostly sunny.
Tuesday Night Fair with high cloud cover over most areas keeping surface temperatures relatively warm.
Wednesday Periods of light rain and snow, increasing in intensity toward evening.

Snow/Freezing Level (ft)

Hurricane Ridge Mt. Baker Washington Pass Leavenworth Stevens Pass Snoqualmie Pass Mt. Rainier, Crystal & White Pass Mt. Hood
Tuesday Morning Freezing Level 4000' 4000' 4500' ' ' 4500' ' 5000'
Tuesday Afternoon Freezing Level 4000' 4500' 5500' ' ' 5500' ' 6000'
Tuesday Night Freezing Level * 3500' 3500' 3500' ' ' 3500' ' 5000'
Wednesday Morning Snow Level * 3500' 4000' 4500' ' ' 4000' ' 4500'
Wednesday Afternoon Snow Level * 4000' 4000' 4500' ' ' 5000' ' 5500'
Hurricane Ridge Elevation
Tuesday Morning Freezing Level
4000'
Tuesday Afternoon Freezing Level
4000'
Tuesday Night Freezing Level
3500'
(Easterly Flow *)
Wednesday Morning Snow Level
3500'
(Easterly Flow *)
Wednesday Afternoon Snow Level
4000'
(Easterly Flow *)
Wednesday Night Snow Level
4000'
(Easterly Flow *)
Mt. Baker Elevation
Tuesday Morning Freezing Level
4000'
Tuesday Afternoon Freezing Level
4500'
Tuesday Night Freezing Level
3500'
(Easterly Flow *)
Wednesday Morning Snow Level
4000'
(Easterly Flow *)
Wednesday Afternoon Snow Level
4000'
(Easterly Flow *)
Wednesday Night Snow Level
4500'
(Easterly Flow *)
Washington Pass Elevation
Tuesday Morning Freezing Level
4500'
Tuesday Afternoon Freezing Level
5500'
Tuesday Night Freezing Level
3500'
(Easterly Flow *)
Wednesday Morning Snow Level
4500'
(Easterly Flow *)
Wednesday Afternoon Snow Level
4500'
(Easterly Flow *)
Wednesday Night Snow Level
4000'
(Easterly Flow *)
Leavenworth Elevation
Tuesday Morning Freezing Level
'
Tuesday Afternoon Freezing Level
'
Tuesday Night Freezing Level
'
(Easterly Flow *)
Wednesday Morning Snow Level
'
(Easterly Flow *)
Wednesday Afternoon Snow Level
'
(Easterly Flow *)
Wednesday Night Snow Level
'
(Easterly Flow *)
Stevens Pass Elevation
Tuesday Morning Freezing Level
'
Tuesday Afternoon Freezing Level
'
Tuesday Night Freezing Level
'
(Easterly Flow *)
Wednesday Morning Snow Level
'
(Easterly Flow *)
Wednesday Afternoon Snow Level
'
(Easterly Flow *)
Wednesday Night Snow Level
'
(Easterly Flow *)
Snoqualmie Pass Elevation
Tuesday Morning Freezing Level
4500'
Tuesday Afternoon Freezing Level
5500'
Tuesday Night Freezing Level
3500'
(Easterly Flow *)
Wednesday Morning Snow Level
4000'
(Easterly Flow *)
Wednesday Afternoon Snow Level
5000'
(Easterly Flow *)
Wednesday Night Snow Level
5000'
(Easterly Flow *)
Mt. Rainier & Crystal Elevation
Tuesday Morning Freezing Level
'
Tuesday Afternoon Freezing Level
'
Tuesday Night Freezing Level
'
(Easterly Flow *)
Wednesday Morning Snow Level
'
(Easterly Flow *)
Wednesday Afternoon Snow Level
'
(Easterly Flow *)
Wednesday Night Snow Level
'
(Easterly Flow *)
Mt. Hood Elevation
Tuesday Morning Freezing Level
5000'
Tuesday Afternoon Freezing Level
6000'
Tuesday Night Freezing Level
5000'
(Easterly Flow *)
Wednesday Morning Snow Level
4500'
(Easterly Flow *)
Wednesday Afternoon Snow Level
5500'
(Easterly Flow *)
Wednesday Night Snow Level
5500'
(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 LT 0.10 LT 0.25
Mt Baker Ski Area LT 0.10 0.25 - 0.50
Washington Pass LT 0.10 LT 0.25
Stevens Pass LT 0.10 LT 0.25
Snoqualmie Pass LT 0.10 LT 0.25
Mission Ridge LT 0.10 0.25 - 0.50
Crystal Mt LT 0.10 0.25 - 0.50
Paradise LT 0.10 0 - 0.50
White Pass LT 0.10 LT 0.25
Mt Hood Meadows LT 0.10 0.50 - 0.75
LT 0.10 0.50 - 0.75

Free Winds at 5000' (mph)

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

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
Tuesday Morning W 10 - 20 W 10 - 20 W 15 - 25 --- - WSW 5 - 15
Tuesday Afternoon WSW 10 - 20 WSW 10 - 20 SW 10 - 20 --- - S 5 - 15
Tuesday Night SSW 15 - 25 SSW 10 - 20 SSW 10 - 20 --- - SSW 20 - 30
Wednesday Morning S 20 - 30 SSE 15 - 25 SSE 15 - 25 --- - SSW 25 - 35
Wednesday Afternoon SSE 20 - 30 SSE 20 - 30 SSW 30 - 40 --- - SSW 20 - 30
Mt. Baker Direction - Speed
Tuesday Morning W 10 - 20
Tuesday Afternoon WSW 10 - 20
Tuesday Night SSW 15 - 25
Wednesday Morning S 20 - 30
Wednesday Afternoon SSE 20 - 30
Wednesday Night SSE 30 - 40
Washington Pass Direction - Speed
Tuesday Morning W 10 - 20
Tuesday Afternoon WSW 10 - 20
Tuesday Night SSW 10 - 20
Wednesday Morning SSE 15 - 25
Wednesday Afternoon SSE 20 - 30
Wednesday Night SSE 30 - 40
Stevens and Snoqualmie Pass Direction - Speed
Tuesday Morning W 15 - 25
Tuesday Afternoon SW 10 - 20
Tuesday Night SSW 10 - 20
Wednesday Morning SSE 15 - 25
Wednesday Afternoon SSW 30 - 40
Wednesday Night S 45 - 65
Mt. Rainier Direction - Speed
Tuesday Morning --- -
Tuesday Afternoon --- -
Tuesday Night --- -
Wednesday Morning --- -
Wednesday Afternoon --- -
Wednesday Night --- -
Mt. Hood Direction - Speed
Tuesday Morning WSW 5 - 15
Tuesday Afternoon S 5 - 15
Tuesday Night SSW 20 - 30
Wednesday Morning SSW 25 - 35
Wednesday Afternoon SSW 20 - 30
Wednesday Night SSE 50 - 70

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.

Jump to: Weather Forecast I Snow/Freezing Level I Precipitation I Free Winds 5k I Free Winds 9k

Previous forecast from Mar 19, 2018

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