Jump to: Weather Forecast I Snow/Freezing Level I Precipitation I Free Winds 5k I Free Winds 9k I Extended Weather
Weather Synopsis for Saturday & Thursday
Another 10-15 inches of generally lower density snow accumulated along the west slopes of the Cascades including the Cascades Passes and in the Olympics for the 24 hours ending 4 am Saturday morning.
A strong westerly jet will remained aimed into Oregon over the weekend leaving the PNW on the cold side of the jet. That said, cool marine air continues to slowly dislodge a colder arctic air mass in place over the east slopes of the Cascades, with a slow warming trend for the Cascade Passes and east slopes today and tonight although snow levels will remain below Pass levels.
A surface trough rotating out of a weak surface low off of Vancouver Island has already begun to increase shower activity this afternoon after a relative break in the action this morning. Light to moderate showers will continue through Sunday before shower activity begins to wane Sunday night. The timing and location of the heaviest shower activity on Sunday is still difficult to pin down but it's safe to say the west slopes of the Cascades and Mt. Hood should continue to pick up moderate amounts of new snow Saturday night and Sunday thanks to good westerly flow and another surface trough swinging through late Sunday morning. A fresh 12-18 inches of snow through Sunday afternoon looks likeliest for Stevens Pass down to Mt. Rainier with Crystal likely being blocked a bit and with higher possible totals down at Mt. Hood.
Weather Forecast
Olympics
| Saturday Mid-day - Saturday Afternoon |
Increasing light to moderate snow showers. |
| Saturday Night - Sunday |
Cloudy with light to occasionally moderate rain and snow showers. |
| Sunday Night |
Mostly cloudy with scattered light snow showers decreasing overnight. |
Washington Cascades near and west of the crest including Stevens, Snoqualmie, and White Passes
| Saturday Afternoon |
Increasing clouds with light to moderate snow showers north part spreading south. Slow warming trend for the Cascade Passes. |
| Saturday Night - Sunday |
Cloudy with light to moderate rain and snow showers, heaviest Stevens and Snoqualmie Passes and Mt. Rainier. |
| Sunday Night |
Mostly cloudy with scattered light snow showers decreasing overnight. |
East slopes of the Washington Cascades
| Saturday Afternoon |
Increasing clouds with light to moderate snow showers developing. Slow warming trend. |
| Saturday Night - Sunday |
Cloudy with light to occasionally moderate rain and snow showers. |
| Sunday Night |
Mostly cloudy with scattered light snow showers decreasing overnight. |
Mt. Hood Area
| Saturday Afternoon - Saturday Night |
Increasing clouds with light to moderate snow showers developing. |
| Sunday |
Moderate to occasionally heavy rain and snow showers. |
| Sunday Night |
Mostly cloudy with scattered light snow showers decreasing overnight. |
Issued: 2:11 PM PST Saturday, December 10, 2016
Snow/Freezing Level (ft)
| Hurricane Ridge | Mt. Baker | Washington Pass | Leavenworth | Stevens Pass | Snoqualmie Pass | Mt. Rainier, Crystal & White Pass | Mt. Hood | ||
|---|---|---|---|---|---|---|---|---|---|
| Saturday Afternoon - Saturday Night | Snow Level | 2500' | 1500' | 1000' | ' | ' | 2000' | ' | 3000' |
| Sunday | Snow Level | 2000' | 1000' | 1000' | ' | ' | 2000' | ' | 2500' |
| Sunday Night | Snow Level | 1000' | 0' | 0' | ' | ' | 1500' | ' | 2000' |
| Hurricane Ridge | Elevation |
|---|---|
| Saturday Afternoon - Saturday Night |
Snow Level 2500' |
| Sunday |
Snow Level 2000' |
| Sunday Night |
Snow Level 1000' |
| Mt. Baker | Elevation |
|---|---|
| Saturday Afternoon - Saturday Night |
Snow Level 1500' |
| Sunday |
Snow Level 1000' |
| Sunday Night |
Snow Level 0' |
| Washington Pass | Elevation |
|---|---|
| Saturday Afternoon - Saturday Night |
Snow Level 1000' |
| Sunday |
Snow Level 1000' |
| Sunday Night |
Snow Level 0' |
| Leavenworth | Elevation |
|---|---|
| Saturday Afternoon - Saturday Night |
Snow Level ' |
| Sunday |
Snow Level ' |
| Sunday Night |
Snow Level ' |
| Stevens Pass | Elevation |
|---|---|
| Saturday Afternoon - Saturday Night |
Snow Level ' |
| Sunday |
Snow Level ' |
| Sunday Night |
Snow Level ' |
| Snoqualmie Pass | Elevation |
|---|---|
| Saturday Afternoon - Saturday Night |
Snow Level 2000' |
| Sunday |
Snow Level 2000' |
| Sunday Night |
Snow Level 1500' |
| Mt. Rainier & Crystal | Elevation |
|---|---|
| Saturday Afternoon - Saturday Night |
Snow Level ' |
| Sunday |
Snow Level ' |
| Sunday Night |
Snow Level ' |
| Mt. Hood | Elevation |
|---|---|
| Saturday Afternoon - Saturday Night |
Snow Level 3000' |
| Sunday |
Snow Level 2500' |
| Sunday Night |
Snow Level 2000' |
* 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
| Thursday | Thursday | |
|---|---|---|
| Hurricane Ridge | 0.50 - 0.75 | 0 - 0.50 |
| Mt Baker Ski Area | 0 - 0.75 | 0.50 - 0.75 |
| Washington Pass | 0.50 - 0.75 | 0.25 - 0.50 |
| Stevens Pass | 0 - 1.00 | 0 - 1.00 |
| Snoqualmie Pass | 0 - 1.00 | 1.00 - 1.50 |
| Mission Ridge | LT 0.25 | LT 0.25 |
| Crystal Mt | 0 - 0.50 | 0 - 0.75 |
| Paradise | 1.00 - 1.50 | 1.50 - 2.00 |
| White Pass | 0 - 0.50 | 0 - 1.00 |
| Mt Hood Meadows | 0.75 - 1.00 | 0 - 1.50 |
| Timberline | 0 - 1.00 | 0 - 2.00 |
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: 2:11 PM PST Saturday, December 10, 2016
Free Winds at 5000' (mph)
| Hurricane Ridge | Mt. Baker | Stevens to Snoqualmie Pass | Mt. Rainier | Mt. Hood | |
|---|---|---|---|---|---|
| Saturday Afternoon | WSW 15 - 25 | S 10 - 20 | SW 20 - 30 | --- - | SW 20 - 30 |
| Saturday Night - Sunday Morning | WSW 15 - 25 | SW 10 - 20 | SW 20 - 35 | --- - | WSW 20 - 35 |
| Sunday Afternoon | W 5 - 15 | W 0 - 10 | WSW 15 - 25 | --- - | W 25 - 35 |
| Sunday Night | N 0 - 10 | NE 5 - 15 | W 5 - 15 | --- - | WNW 15 - 25 |
| Hurricane Ridge | Elevation |
|---|---|
| Saturday Afternoon | WSW 15 - 25 |
| Saturday Night - Sunday Morning | WSW 15 - 25 |
| Sunday Afternoon | W 5 - 15 |
| Sunday Night | N 0 - 10 |
| Mt. Baker | Elevation |
|---|---|
| Saturday Afternoon | S 10 - 20 |
| Saturday Night - Sunday Morning | SW 10 - 20 |
| Sunday Afternoon | W 0 - 10 |
| Sunday Night | NE 5 - 15 |
| Stevens and Snoqualmie Pass | Elevation |
|---|---|
| Saturday Afternoon | SW 20 - 30 |
| Saturday Night - Sunday Morning | SW 20 - 35 |
| Sunday Afternoon | WSW 15 - 25 |
| Sunday Night | W 5 - 15 |
| Mt. Rainier | Elevation |
|---|---|
| Saturday Afternoon | --- - |
| Saturday Night - Sunday Morning | --- - |
| Sunday Afternoon | --- - |
| Sunday Night | --- - |
| Mt. Hood | Elevation |
|---|---|
| Saturday Afternoon | SW 20 - 30 |
| Saturday Night - Sunday Morning | WSW 20 - 35 |
| Sunday Afternoon | W 25 - 35 |
| Sunday Night | WNW 15 - 25 |
| Hurricane Ridge | Direction - Speed |
|---|---|
| Saturday Afternoon | WSW 15 - 25 |
| Saturday Night - Sunday Morning | WSW 15 - 25 |
| Sunday Afternoon | W 5 - 15 |
| Sunday Night | N 0 - 10 |
| Mt. Baker | Direction - Speed |
|---|---|
| Saturday Afternoon | S 10 - 20 |
| Saturday Night - Sunday Morning | SW 10 - 20 |
| Sunday Afternoon | W 0 - 10 |
| Sunday Night | NE 5 - 15 |
| Stevens and Snoqualmie Pass | Direction - Speed |
|---|---|
| Saturday Afternoon | SW 20 - 30 |
| Saturday Night - Sunday Morning | SW 20 - 35 |
| Sunday Afternoon | WSW 15 - 25 |
| Sunday Night | W 5 - 15 |
| Mt. Rainier | Direction - Speed |
|---|---|
| Saturday Afternoon | --- - |
| Saturday Night - Sunday Morning | --- - |
| Sunday Afternoon | --- - |
| Sunday Night | --- - |
| Mt. Hood | Direction - Speed |
|---|---|
| Saturday Afternoon | SW 20 - 30 |
| Saturday Night - Sunday Morning | WSW 20 - 35 |
| Sunday Afternoon | W 25 - 35 |
| Sunday Night | WNW 15 - 25 |
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 | |
|---|---|---|---|---|---|
| Saturday Afternoon | SW 20 - 30 | SW 15 - 25 | W 20 - 30 | --- - | W 25 - 35 |
| Saturday Night - Sunday Morning | SW 25 - 40 | WSW 15 - 25 | WSW 35 - 50 | --- - | W 35 - 50 |
| Sunday Afternoon | W 10 - 20 | W 10 - 20 | W 20 - 30 | --- - | W 40 - 50 |
| Sunday Night | W 10 - 20 | WNW 15 - 25 | W 25 - 35 | --- - | WNW 30 - 40 |
| Mt. Baker | Direction - Speed |
|---|---|
| Saturday Afternoon | SW 20 - 30 |
| Saturday Night - Sunday Morning | SW 25 - 40 |
| Sunday Afternoon | W 10 - 20 |
| Sunday Night | W 10 - 20 |
| Washington Pass | Direction - Speed |
|---|---|
| Saturday Afternoon | SW 15 - 25 |
| Saturday Night - Sunday Morning | WSW 15 - 25 |
| Sunday Afternoon | W 10 - 20 |
| Sunday Night | WNW 15 - 25 |
| Stevens and Snoqualmie Pass | Direction - Speed |
|---|---|
| Saturday Afternoon | W 20 - 30 |
| Saturday Night - Sunday Morning | WSW 35 - 50 |
| Sunday Afternoon | W 20 - 30 |
| Sunday Night | W 25 - 35 |
| Mt. Rainier | Direction - Speed |
|---|---|
| Saturday Afternoon | --- - |
| Saturday Night - Sunday Morning | --- - |
| Sunday Afternoon | --- - |
| Sunday Night | --- - |
| Mt. Hood | Direction - Speed |
|---|---|
| Saturday Afternoon | W 25 - 35 |
| Saturday Night - Sunday Morning | W 35 - 50 |
| Sunday Afternoon | W 40 - 50 |
| Sunday Night | WNW 30 - 40 |
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: 2:11 PM PST Saturday, December 10, 2016
Extended Weather Synopsis for Thursday night through Thursday
Weak upper level ridging will build along the coast Monday but not before a weak surface low passes through the Cascades midday perhaps leading to another round of light snow for the central/south Cascades and even along the east slopes.
With the jet stream to our south and surface high pressure over the Canadian interior, cold and fair weather should begin to settle into our region Monday night and may stick around for awhile. Forecast models indicate easterly flow will increase on Tuesday, so we may get another round of cold easterly flow for the central and south Cascades through midweek. Systems passing through California and Oregon may clip Mt. Hood and the south Washington Cascades with increased cloud cover Tuesday and Wednesday.
Extended Weather
Olympics, Washington Cascades and Mt. Hood area
Mostly clear and cold north and central Cascades, mostly to partly cloudy south Washington Cascades and Mt. Hood. Moderate easterly Pass winds and ridgetop winds south Washington Cascades to Mt. Hood.
Mostly cloudy with periods of light snow possible central and south Washington Cascades.
Partly to mostly cloudy with light showers ending.
Extended Snow/Freezing Levels
| Mt. Baker | Snoqualmie Pass | Mt. Hood | Easterly Flow * | ||
|---|---|---|---|---|---|
| Monday - Monday Night | Snow Level | 0' - 1000' | 500' - 1500' | 1500' - 2500' | |
| Tuesday - Wednesday | Freezing Level | 0' - 1000' | 0' - 1000' | 0' - 1000' | * |
| Mt. Baker | Elevation |
|---|---|
| Monday - Monday Night |
Snow Level 0' - 1000' |
| Tuesday - Wednesday |
Freezing Level 0' - 1000' (Easterly Flow *) |
| Snoqualmie Pass | Elevation |
|---|---|
| Monday - Monday Night |
Snow Level 500' - 1500' |
| Tuesday - Wednesday |
Freezing Level 0' - 1000' (Easterly Flow *) |
| Mt. Hood | Elevation |
|---|---|
| Monday - Monday Night |
Snow Level 1500' - 2500' |
| Tuesday - Wednesday |
Freezing Level 0' - 1000' (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.
Jump to: Weather Forecast I Snow/Freezing Level I Precipitation I Free Winds 5k I Free Winds 9k I Extended Weather
Previous forecast from Dec 10, 2016
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