Issued: 7:38 AM PDT Sunday, March 15, 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

The second frontal wave developing along a juicy SW-NE oriented plume of moisture draped over the PNW today will bring another round of active weather to the region. Surface low pressure is developing off the WA/OR coast and is forecast to deepen and track NE across the Olympic peninsula today. While the heaviest precipitation totals are likely in the south Washington Cascades, the snow level will slowly creep up from 5500-6000 ft this morning over this area. The Cascade Passes are seeing an influx of cool easterly flow... which will locally maintain the snow levels around 4000 ft until warmer air pushes in this afternoon. The biggest snow benefactor from this system should be the Olympics and north Cascades... where snow levels should stay below 4500 ft most of the day with a healthy dose of snowfall today through early Sunday night.  

The low pressure system will lift NE and across the Cascades tonight... with light to moderate showers tapering down across the area through Monday morning.  Weak upper level ridging should build over the area Monday afternoon, but leftover moisture and a few isolated showers should make for a mostly cloudy day.  

Weather Forecast

Olympics, north Washington Cascades
Sunday Morning

Light to occasionally moderate rain and snow. 
Sunday Afternoon - Sunday Evening

Moderate to occasionally heavy rain and snow. Slight warming trend. 
Sunday Night - Monday Morning

Light to moderate rain and snow showers.  Slight cooling trend. 
Monday Afternoon - Monday Night

Mostly cloudy with isolated light rain and snow showers tapering off in the early evening. 
South and central Washington Cascades including Stevens, Snoqualmie, and White Passes
Sunday Morning

Moderate to occasionally heavy rain and snow. 
Sunday Afternoon - Sunday Evening

Moderate to occasionally heavy rain and snow becoming light to moderate showers from south to north in the afternoon. Warming trend. 
Sunday Night - Monday Morning

Light to occasionally moderate rain and snow showers.  Slight cooling trend. 
Monday Afternoon - Monday Night

Mostly cloudy with isolated light rain and snow showers tapering off in the early evening. 
Mt. Hood Area
Sunday Morning

Moderate rain and snow. Mild. 
Sunday Afternoon

Cloudy with periods of light rain and snow. Mild.  
Sunday Night - Monday Morning

Light to occasionally moderate rain and snow becoming showers overnight.  Slight cooling trend. 
Monday Afternoon - Monday Night

Mostly cloudy with isolated light rain and snow showers tapering off in the early evening and becoming partly cloudy. 

Issued: 7:38 AM PDT Sunday, March 15, 2015

Snow/Freezing Level (ft)

Hurricane Ridge Mt. Baker Washington Pass Leavenworth Stevens Pass Snoqualmie Pass Mt. Rainier, Crystal & White Pass Mt. Hood
Sunday Morning Snow Level * 3500' 3500' 3500' ' ' 5000' ' 7000'
Sunday Mid-day Snow Level * 4000' 4000' 4000' ' ' 6000' ' 6500'
Sunday Afternoon Snow Level * 4000' 4500' 5000' ' ' 7000' ' 7000'
Sunday Night - Monday Morning Snow Level 3500' 3500' 4000' ' ' 4000' ' 5000'
Monday Afternoon - Monday Night Snow Level 5000' 5000' 4500' ' ' 6000' ' 6500'
Hurricane Ridge Elevation
Sunday Morning Snow Level
3500'
(Easterly Flow *)
Sunday Mid-day Snow Level
4000'
(Easterly Flow *)
Sunday Afternoon Snow Level
4000'
(Easterly Flow *)
Sunday Night - Monday Morning Snow Level
3500'
Monday Afternoon - Monday Night Snow Level
5000'
Mt. Baker Elevation
Sunday Morning Snow Level
3500'
(Easterly Flow *)
Sunday Mid-day Snow Level
4000'
(Easterly Flow *)
Sunday Afternoon Snow Level
4500'
(Easterly Flow *)
Sunday Night - Monday Morning Snow Level
3500'
Monday Afternoon - Monday Night Snow Level
5000'
Washington Pass Elevation
Sunday Morning Snow Level
3500'
(Easterly Flow *)
Sunday Mid-day Snow Level
4000'
(Easterly Flow *)
Sunday Afternoon Snow Level
5000'
(Easterly Flow *)
Sunday Night - Monday Morning Snow Level
4000'
Monday Afternoon - Monday Night Snow Level
4500'
Leavenworth Elevation
Sunday Morning Snow Level
'
(Easterly Flow *)
Sunday Mid-day Snow Level
'
(Easterly Flow *)
Sunday Afternoon Snow Level
'
(Easterly Flow *)
Sunday Night - Monday Morning Snow Level
'
Monday Afternoon - Monday Night Snow Level
'
Stevens Pass Elevation
Sunday Morning Snow Level
'
(Easterly Flow *)
Sunday Mid-day Snow Level
'
(Easterly Flow *)
Sunday Afternoon Snow Level
'
(Easterly Flow *)
Sunday Night - Monday Morning Snow Level
'
Monday Afternoon - Monday Night Snow Level
'
Snoqualmie Pass Elevation
Sunday Morning Snow Level
5000'
(Easterly Flow *)
Sunday Mid-day Snow Level
6000'
(Easterly Flow *)
Sunday Afternoon Snow Level
7000'
(Easterly Flow *)
Sunday Night - Monday Morning Snow Level
4000'
Monday Afternoon - Monday Night Snow Level
6000'
Mt. Rainier & Crystal Elevation
Sunday Morning Snow Level
'
(Easterly Flow *)
Sunday Mid-day Snow Level
'
(Easterly Flow *)
Sunday Afternoon Snow Level
'
(Easterly Flow *)
Sunday Night - Monday Morning Snow Level
'
Monday Afternoon - Monday Night Snow Level
'
Mt. Hood Elevation
Sunday Morning Snow Level
7000'
(Easterly Flow *)
Sunday Mid-day Snow Level
6500'
(Easterly Flow *)
Sunday Afternoon Snow Level
7000'
(Easterly Flow *)
Sunday Night - Monday Morning Snow Level
5000'
Monday Afternoon - Monday Night Snow 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

Monday Monday
Hurricane Ridge 1.00 - 2.00 LT 0.10
Mt Baker Ski Area 1.00 - 2.00 LT 0.10
Washington Pass 1.00 - 2.00 LT 0.10
Stevens Pass 1.00 - 1.50 LT 0.10
Snoqualmie Pass 1.50 - 2.00 LT 0.10
Mission Ridge 0 - 1.00 LT 0.10
Crystal Mt 0 - 2.00 LT 0.10
Paradise 0 - 3.00 LT 0.10
White Pass 1.00 - 1.50 LT 0.10
Mt Hood Meadows 0.50 - 0.75 LT 0.10
Timberline 0 - 0.75 LT 0.10

LT = less than; WE or Water equivalent is the liquid water equivalent of melted snow in hundredths of inches. As a rough approximation 1 inch of snow = about .10 inches WE, or 10 inches of snow = about 1 inch WE.

Issued: 7:38 AM PDT Sunday, March 15, 2015

Free Winds at 5000' (mph)

Hurricane Ridge Mt. Baker Stevens to Snoqualmie Pass Mt. Rainier Mt. Hood
Sunday Morning NE 5 - 15 E 5 - 15 SE 15 - 25 --- - SW 20 - 30
Sunday Afternoon NE 10 - 20 SE 5 - 15 SSW 20 - 30 --- - SW 35 - 50
Sunday Night N 10 - 20 NE 10 - 20 WSW 15 - 30 --- - W 20 - 30
Monday E 0 - 10 E 0 - 10 E 5 - 15 --- - E 5 - 15
Monday Night S 5 - 15 SE 0 - 10 SE 5 - 15 --- - SE 5 - 15
Hurricane Ridge Elevation
Sunday Morning NE 5 - 15
Sunday Afternoon NE 10 - 20
Sunday Night N 10 - 20
Monday E 0 - 10
Monday Night S 5 - 15
Mt. Baker Elevation
Sunday Morning E 5 - 15
Sunday Afternoon SE 5 - 15
Sunday Night NE 10 - 20
Monday E 0 - 10
Monday Night SE 0 - 10
Stevens and Snoqualmie Pass Elevation
Sunday Morning SE 15 - 25
Sunday Afternoon SSW 20 - 30
Sunday Night WSW 15 - 30
Monday E 5 - 15
Monday Night SE 5 - 15
Mt. Rainier Elevation
Sunday Morning --- -
Sunday Afternoon --- -
Sunday Night --- -
Monday --- -
Monday Night --- -
Mt. Hood Elevation
Sunday Morning SW 20 - 30
Sunday Afternoon SW 35 - 50
Sunday Night W 20 - 30
Monday E 5 - 15
Monday Night SE 5 - 15
Hurricane Ridge Direction - Speed
Sunday Morning NE 5 - 15
Sunday Afternoon NE 10 - 20
Sunday Night N 10 - 20
Monday E 0 - 10
Monday Night S 5 - 15
Mt. Baker Direction - Speed
Sunday Morning E 5 - 15
Sunday Afternoon SE 5 - 15
Sunday Night NE 10 - 20
Monday E 0 - 10
Monday Night SE 0 - 10
Stevens and Snoqualmie Pass Direction - Speed
Sunday Morning SE 15 - 25
Sunday Afternoon SSW 20 - 30
Sunday Night WSW 15 - 30
Monday E 5 - 15
Monday Night SE 5 - 15
Mt. Rainier Direction - Speed
Sunday Morning --- -
Sunday Afternoon --- -
Sunday Night --- -
Monday --- -
Monday Night --- -
Mt. Hood Direction - Speed
Sunday Morning SW 20 - 30
Sunday Afternoon SW 35 - 50
Sunday Night W 20 - 30
Monday E 5 - 15
Monday Night SE 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 Morning SW 10 - 20 SW 15 - 25 SW 35 - 45 --- - SW 40 - 50
Sunday Afternoon SSW 25 - 35 SSW 20 - 30 SW 60 - 70 --- - SW 60 - 70
Sunday Night VAR 5 - 15 W 5 - 15 W 35 - 50 --- - W 40 - 50
Monday Morning NW 5 - 15 NW 10 - 20 NW 25 - 35 --- - W 20 - 30
Monday Afternoon - Monday Night SW 5 - 15 WSW 5 - 15 SW 5 - 15 --- - SW 10 - 20
Mt. Baker Direction - Speed
Sunday Morning SW 10 - 20
Sunday Afternoon SSW 25 - 35
Sunday Night VAR 5 - 15
Monday Morning NW 5 - 15
Monday Afternoon - Monday Night SW 5 - 15
Washington Pass Direction - Speed
Sunday Morning SW 15 - 25
Sunday Afternoon SSW 20 - 30
Sunday Night W 5 - 15
Monday Morning NW 10 - 20
Monday Afternoon - Monday Night WSW 5 - 15
Stevens and Snoqualmie Pass Direction - Speed
Sunday Morning SW 35 - 45
Sunday Afternoon SW 60 - 70
Sunday Night W 35 - 50
Monday Morning NW 25 - 35
Monday Afternoon - Monday Night SW 5 - 15
Mt. Rainier Direction - Speed
Sunday Morning --- -
Sunday Afternoon --- -
Sunday Night --- -
Monday Morning --- -
Monday Afternoon - Monday Night --- -
Mt. Hood Direction - Speed
Sunday Morning SW 40 - 50
Sunday Afternoon SW 60 - 70
Sunday Night W 40 - 50
Monday Morning W 20 - 30
Monday Afternoon - Monday Night SW 10 - 20

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.

Issued: 7:38 AM PDT Sunday, March 15, 2015

Extended Weather Synopsis for Monday night through Monday

A weak Pacific frontal system will approach Monday night and push over the Cascades Tuesday. This front should produce only light amounts of precipitation at moderate snow levels... with very light amounts likely for the Mt. Hood area. Weak ridging will try to rebuild Tuesday night and give us a dry day on Wednesday... but another weak system should be approaching from the west during the afternoon. 

The ridge should quickly shift east Wednesday night with light rain and snow from a frontal boundary hanging up mostly over the Olympics and north Cascades on Thursday.  

Extended Weather

Olympics, Washington Cascades and Mt. Hood Area
Tuesday

Occasional light rain and snow. 

Tuesday Night - Wednesday

Partly to mostly cloudy. 

Wednesday Night - Thursday

Increasing clouds Wednesday night with light rain and snow developing Thursday, especially Olympics and north Cascades. 

Extended Snow/Freezing Levels

Mt. Baker Snoqualmie Pass Mt. Hood Easterly Flow *
Tuesday Snow Level 4500' - 5500' 5000' - 6000' 5500' - 6500'
Tuesday Night - Wednesday Freezing Level 5000' - 6000' 5000' - 6500' 6000' - 8000'
Thursday Snow Level 4500' - 5500' 5000' - 6000' 6000' - 7000'
Mt. Baker Elevation
Tuesday Snow Level
4500' - 5500'
Tuesday Night - Wednesday Freezing Level
5000' - 6000'
Thursday Snow Level
4500' - 5500'
Snoqualmie Pass Elevation
Tuesday Snow Level
5000' - 6000'
Tuesday Night - Wednesday Freezing Level
5000' - 6500'
Thursday Snow Level
5000' - 6000'
Mt. Hood Elevation
Tuesday Snow Level
5500' - 6500'
Tuesday Night - Wednesday Freezing Level
6000' - 8000'
Thursday Snow Level
6000' - 7000'

* 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 14, 2015

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