Issued: 1:36 PM PDT Sunday, April 5, 2015
by Dennis D'Amico

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

Weather Synopsis for Sunday & Monday

A cool upper low offshore will continue to be the main weather feature over the area for the next several days. Mid and high clouds from an upper level shortwave are spreading north over the area this morning. With an unstable air mass still overhead...scattered and generally light afternoon and early evening showers should develop once again over the Cascades and Olympics.

The exception should be down near Mt. Hood where a shortwave currently located off the Oregon coast should rotate around through in the evening... bringing a period of moderate showers through the overnight. Sunday night through mid-day Monday an area of upper level deformation may bring another opportunity for moderate precipitation...this time to the central Cascades including the east slopes. However, there is only fair confidence in the timing and axis of this feature. The upper low will continue drifting south along the coast Monday night.  

Weather Forecast

Olympics, Washington Cascades
Sunday Mid-day

Partly sunny north Cascades and Olympics, mostly cloudy with filtered sunshine central and south Cascades. 

Sunday Afternoon - Sunday Evening

Mostly cloudy with scattered light rain and snow showers. 

Sunday Night - Monday Mid-day

Cloudy with light rain and snow showers, except occasionally moderate south and central Washington Cascades.  

Mt. Hood Area
Sunday Afternoon - Sunday Night

Cloudy with light rain and snow showers becoming moderate late afternoon and evening. 

Monday Afternoon - Monday Night

Mostly cloudy 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
Sunday Afternoon Snow Level 3500' 4000' 3500' ' ' 3500' ' 4000'
Sunday Night - Monday Morning Snow Level 3000' 3000' 2500' ' ' 2500' ' 2500'
Monday Afternoon Snow Level 4000' 4000' 4000' ' ' 4000' ' 4000'
Hurricane Ridge Elevation
Sunday Afternoon Snow Level
3500'
Sunday Night - Monday Morning Snow Level
3000'
Monday Afternoon Snow Level
4000'
Monday Night Snow Level
3500'
Mt. Baker Elevation
Sunday Afternoon Snow Level
4000'
Sunday Night - Monday Morning Snow Level
3000'
Monday Afternoon Snow Level
4000'
Monday Night Snow Level
3500'
Washington Pass Elevation
Sunday Afternoon Snow Level
3500'
Sunday Night - Monday Morning Snow Level
2500'
Monday Afternoon Snow Level
4000'
Monday Night Snow Level
3000'
Leavenworth Elevation
Sunday Afternoon Snow Level
'
Sunday Night - Monday Morning Snow Level
'
Monday Afternoon Snow Level
'
Monday Night Snow Level
'
Stevens Pass Elevation
Sunday Afternoon Snow Level
'
Sunday Night - Monday Morning Snow Level
'
Monday Afternoon Snow Level
'
Monday Night Snow Level
'
Snoqualmie Pass Elevation
Sunday Afternoon Snow Level
3500'
Sunday Night - Monday Morning Snow Level
2500'
Monday Afternoon Snow Level
4000'
Monday Night Snow Level
3000'
Mt. Rainier & Crystal Elevation
Sunday Afternoon Snow Level
'
Sunday Night - Monday Morning Snow Level
'
Monday Afternoon Snow Level
'
Monday Night Snow Level
'
Mt. Hood Elevation
Sunday Afternoon Snow Level
4000'
Sunday Night - Monday Morning Snow Level
2500'
Monday Afternoon Snow Level
4000'
Monday 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

Monday Monday
Hurricane Ridge LT 0.10 LT 0.10
Mt Baker Ski Area LT 0.10 LT 0.10
Washington Pass LT 0.10 LT 0.25
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 LT 0.25
Paradise LT 0.10 LT 0.25
White Pass LT 0.10 LT 0.25
Mt Hood Meadows 0 - 0.75 LT 0.25
0.75 - 1.00 LT 0.25

Free Winds at 5000' (mph)

Hurricane Ridge Mt. Baker Stevens to Snoqualmie Pass Mt. Rainier Mt. Hood
Sunday Afternoon SE 0 - 10 W 0 - 10 E 5 - 15 --- - S 5 - 15
Sunday Night - Monday Morning E 0 - 10 NE 0 - 10 W 0 - 10 --- - SW 10 - 20
Hurricane Ridge Elevation
Sunday Afternoon SE 0 - 10
Sunday Night - Monday Morning E 0 - 10
Monday Afternoon - Monday Night NE 0 - 10
Mt. Baker Elevation
Sunday Afternoon W 0 - 10
Sunday Night - Monday Morning NE 0 - 10
Monday Afternoon - Monday Night VAR 0 - 10
Stevens and Snoqualmie Pass Elevation
Sunday Afternoon E 5 - 15
Sunday Night - Monday Morning W 0 - 10
Monday Afternoon - Monday Night VAR 0 - 10
Mt. Rainier Elevation
Sunday Afternoon --- -
Sunday Night - Monday Morning --- -
Monday Afternoon - Monday Night --- -
Mt. Hood Elevation
Sunday Afternoon S 5 - 15
Sunday Night - Monday Morning SW 10 - 20
Monday Afternoon - Monday Night ESE 5 - 15
Hurricane Ridge Direction - Speed
Sunday Afternoon SE 0 - 10
Sunday Night - Monday Morning E 0 - 10
Monday Afternoon - Monday Night NE 0 - 10
Mt. Baker Direction - Speed
Sunday Afternoon W 0 - 10
Sunday Night - Monday Morning NE 0 - 10
Monday Afternoon - Monday Night VAR 0 - 10
Stevens and Snoqualmie Pass Direction - Speed
Sunday Afternoon E 5 - 15
Sunday Night - Monday Morning W 0 - 10
Monday Afternoon - Monday Night VAR 0 - 10
Mt. Rainier Direction - Speed
Sunday Afternoon --- -
Sunday Night - Monday Morning --- -
Monday Afternoon - Monday Night --- -
Mt. Hood Direction - Speed
Sunday Afternoon S 5 - 15
Sunday Night - Monday Morning SW 10 - 20
Monday Afternoon - Monday Night ESE 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
Sunday Afternoon - Sunday Evening E 0 - 10 E 0 - 10 ESE 5 - 15 --- - S 5 - 15
Sunday Night - Monday Morning VAR 0 - 10 VAR 0 - 10 W 0 - 10 --- - W 15 - 25
Monday Afternoon VAR 0 - 10 VAR 0 - 10 VAR 0 - 10 --- - S 10 - 20
Mt. Baker Direction - Speed
Sunday Afternoon - Sunday Evening E 0 - 10
Sunday Night - Monday Morning VAR 0 - 10
Monday Afternoon VAR 0 - 10
Monday Night S 0 - 10
Washington Pass Direction - Speed
Sunday Afternoon - Sunday Evening E 0 - 10
Sunday Night - Monday Morning VAR 0 - 10
Monday Afternoon VAR 0 - 10
Monday Night S 0 - 10
Stevens and Snoqualmie Pass Direction - Speed
Sunday Afternoon - Sunday Evening ESE 5 - 15
Sunday Night - Monday Morning W 0 - 10
Monday Afternoon VAR 0 - 10
Monday Night SE 5 - 15
Mt. Rainier Direction - Speed
Sunday Afternoon - Sunday Evening --- -
Sunday Night - Monday Morning --- -
Monday Afternoon --- -
Monday Night --- -
Mt. Hood Direction - Speed
Sunday Afternoon - Sunday Evening S 5 - 15
Sunday Night - Monday Morning W 15 - 25
Monday Afternoon S 10 - 20
Monday Night SE 5 - 15

Extended Weather Synopsis for Monday night through Monday

The upper low will transition into an elongated trough and eject inland on Tuesday. Mostly cloudy skies and showers are likely especially for southern areas like Mt. Hood and the south Washington Cascades Tuesday, while more sunbreaks and less shower activity is possible further north.  An upper ridge will begin to build offshore Wednesday and should push over the PNW on Thursday as a drying and slow warming trend ensues. 

Extended Weather

Olympics, Washington Cascades and Mt. Hood area
Tuesday - Tuesday Night

Light to moderate rain and snow showers south and central Cascades.  Mostly cloudy with scattered light showers Olympics and north Cascades. 

Wednesday

Partly sunny with isolated light afternoon and early evening showers. 

Wednesday Night - Thursday

Mostly clear.  

Extended Snow/Freezing Levels

Mt. Baker Snoqualmie Pass Mt. Hood Easterly Flow *
Tuesday - Tuesday Night Snow Level 4000' - 5000' 4000' - 5000' 4000' - 5000'
Wednesday - Wednesday Night Snow Level 4500' - 5500' 4500' - 5500' 4500' - 5500'
Mt. Baker Elevation
Tuesday - Tuesday Night Snow Level
4000' - 5000'
Wednesday - Wednesday Night Snow Level
4500' - 5500'
Thursday Freezing Level
6500' - 7500'
Snoqualmie Pass Elevation
Tuesday - Tuesday Night Snow Level
4000' - 5000'
Wednesday - Wednesday Night Snow Level
4500' - 5500'
Thursday Freezing Level
6500' - 7500'
Mt. Hood Elevation
Tuesday - Tuesday Night Snow Level
4000' - 5000'
Wednesday - Wednesday Night Snow Level
4500' - 5500'
Thursday Freezing Level
6500' - 7500'

* 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 Apr 5, 2015

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Spring Announcement: The last daily NWAC mountain weather and avalanche forecasts for this season will be issued on Saturday, April 11th.

For the remainder of April, NWAC mountain weather and avalanche forecasts will be issued on April 17th, 18th, 24th and 25th to provide weekend forecasts. For all other times this spring, Special Avalanche Advisories will be issued by NWAC if unusually severe avalanche conditions are expected. Thank you for your support!