Issued: 7:41 AM PDT Thursday, March 15, 2018
by Dennis D'Amico

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

Weather Synopsis for Thursday & Sunday

A deep upper trough will slowly spin south off the Oregon Coast today. This should translate to more clouds and shower activity closer to the low near Mt. Hood. The air mass is marginally unstable, so a general increase in afternoon cover near or above Cascade crest level is expected over the Washington Cascades. Isolated showers may pop-up in the afternoon espeically in the Crystal/Mt. Rainier vicinity.  Any shower activity that does form will generally dissipate overnight. Freezing levels will climb to 5000 or more feet today, but snow levels will quickly plummet during any shower activity. 

The low will migrate inland on Friday with the same cool and slightly unstable air mass over our region. A notch more cloud buildup and afternoon light shower activity can be expected on Friday.   

Weather Forecast

Olympics
Thursday Mostly clear becoming partly cloudy in the afternoon. Isolated afternoon showers.
Thursday Night Partly to mostly clear.
Friday Mostly clear becoming mostly cloudy in the afternoon with isolated showers.
Washington Cascades near and west of the Crest including Stevens, Snoqualmie and White Passes
Thursday Mostly clear becoming partly cloudy north and central Cascades and partly to mostly cloudy south Cascades in the afternoon. Isolated afternoon showers from Snoqualmie Pass and southward.
Thursday Night Partly to mostly clear.
Friday Mostly clear becoming mostly cloudy in the afternoon with isolated showers.
East Slopes of the Washington Cascades
Thursday Mostly clear becoming partly cloudy northeast and central-east Cascades and partly to mostly cloudy southeast Cascades in the afternoon. Isolated afternoon showers from Snoqualmie Pass and southward near the Cascade crest.
Thursday Night Partly to mostly clear.
Friday Mostly clear becoming mostly cloudy in the afternoon with isolated showers near the Cascade crest.
Mt. Hood
Thursday Mostly cloudy becoming cloudy in the afternoon with light rain and snow showers.
Thursday Night Mostly cloudy with light rain and snow showers.
Friday Mostly cloudy becoming cloudy in the afternoon with light rain and snow showers.

Snow/Freezing Level (ft)

Hurricane Ridge Mt. Baker Washington Pass Leavenworth Stevens Pass Snoqualmie Pass Mt. Rainier, Crystal & White Pass Mt. Hood
Thursday Morning Snow Level 1500' 1000' 500' ' ' 1500' ' 1500'
Thursday Afternoon Snow Level 3000' 3500' 4000' ' ' 3500' ' 3500'
Thursday Night Snow Level 2500' 2500' 1500' ' ' 2500' ' 2500'
Friday Morning Snow Level 2500' 2500' 1500' ' ' 2500' ' 2500'
Friday Afternoon Snow Level 3500' 4500' 4500' ' ' 4500' ' 3500'
Hurricane Ridge Elevation
Thursday Morning Snow Level
1500'
Thursday Afternoon Snow Level
3000'
Thursday Night Snow Level
2500'
Friday Morning Snow Level
2500'
Friday Afternoon Snow Level
3500'
Friday Night Snow Level
3000'
Mt. Baker Elevation
Thursday Morning Snow Level
1000'
Thursday Afternoon Snow Level
3500'
Thursday Night Snow Level
2500'
Friday Morning Snow Level
2500'
Friday Afternoon Snow Level
4500'
Friday Night Snow Level
2500'
Washington Pass Elevation
Thursday Morning Snow Level
500'
Thursday Afternoon Snow Level
4000'
Thursday Night Snow Level
1500'
Friday Morning Snow Level
1500'
Friday Afternoon Snow Level
4500'
Friday Night Snow Level
2000'
Leavenworth Elevation
Thursday Morning Snow Level
'
Thursday Afternoon Snow Level
'
Thursday Night Snow Level
'
Friday Morning Snow Level
'
Friday Afternoon Snow Level
'
Friday Night Snow Level
'
Stevens Pass Elevation
Thursday Morning Snow Level
'
Thursday Afternoon Snow Level
'
Thursday Night Snow Level
'
Friday Morning Snow Level
'
Friday Afternoon Snow Level
'
Friday Night Snow Level
'
Snoqualmie Pass Elevation
Thursday Morning Snow Level
1500'
Thursday Afternoon Snow Level
3500'
Thursday Night Snow Level
2500'
Friday Morning Snow Level
2500'
Friday Afternoon Snow Level
4500'
Friday Night Snow Level
2500'
Mt. Rainier & Crystal Elevation
Thursday Morning Snow Level
'
Thursday Afternoon Snow Level
'
Thursday Night Snow Level
'
Friday Morning Snow Level
'
Friday Afternoon Snow Level
'
Friday Night Snow Level
'
Mt. Hood Elevation
Thursday Morning Snow Level
1500'
Thursday Afternoon Snow Level
3500'
Thursday Night Snow Level
2500'
Friday Morning Snow Level
2500'
Friday Afternoon Snow Level
3500'
Friday Night Snow Level
3000'

* 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

Sunday Sunday
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 0.25 LT 0.25
LT 0.25 LT 0.25

Free Winds at 5000' (mph)

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

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

Previous forecast from Mar 11, 2018

The NWAC program is administered by the USDA-Forest Service and operates from the National Weather Service Forecast Office in Seattle. NWAC services are made possible by important collaboration and support from a wide variety of federal, state and private cooperators.