Issued: 2:07 PM PST Wednesday, November 20, 2024
by Dennis D'Amico

Jump to: Weather Forecast I Precipitation I Snow Level I 5000' Temps I Ridgeline Winds I Extended Weather

Weather Synopsis

The "big blow" relented this morning but the same deep low pressure system that brought strong winds E-SE (especially to the western Cascade foothills) and light to moderate mountain snow continues to spin off of Vancouver Island this afternoon. The low continues to rotate light to moderate showers over the Olympic peninsula and a mix of cloud cover and light showers elsewhere. This pattern will continue through Thursday with the most notable weather feature being the slight uptick in snow levels by Thursday afternoon into the 3500-4500' range across the region.

Another low pressure system will deepen rapidly off the Oregon coast Thursday night.  Warm frontal precipitation will spread from south to north over the area and feature a similar pattern to Tuesday night's storm.  We can expect the southern Cascades, the east slopes of the Cascades in general, and Mt Hood to pull down some moderate precipitation amounts Thursday night and Friday.  E-SE offshore winds will pick up Thursday night into Friday morning and become strong but should be a notch lower than Tuesday's peak winds. Cold air pooled along the east slopes of the Cascades and flowing through the Cascade passes will help keep snow levels lower relative to the west side where rain will mix in earlier at lower elevation trailheads. That said all areas will see a slow but steady warming trend with snow levels settling into the 4000-5000' over the Cascades by Friday afternoon as the precipitation tapers off.  There could some localized areas of freezing rain near Snoqualmie Pass for areas due east, but it won't be a main feature of the storm.  Mt Hood will bear the brunt of the warming with snow levels shooting up to 7000-8000' on Friday. 

Weather Forecast

Olympics
West North
West Central
West South
Stevens Pass
Snoqualmie Pass
East North
East Central
East South
Mt. Hood
Use dropdown to select your zone
Wednesday Night Mostly cloudy with light to occasionally moderate rain and snow showers, especially south slopes of the Olympics.
Thursday Mostly cloudy with light rain and snow showers, especially south slopes of the Olympics.
Wednesday Night Mostly cloudy with scattered light rain or snow showers.
Thursday Mostly cloudy with scattered light rain or snow showers.
Wednesday Night Mostly cloudy with scattered light rain or snow showers.
Thursday Mostly cloudy with scattered light rain or snow showers.
Wednesday Night Mostly cloudy with scattered light rain or snow showers. Light to occasionally moderate E winds at Pass level.
Thursday Mostly cloudy with scattered light rain or snow showers. Light to occasionally moderate E winds at Pass level.
Wednesday Night Mostly cloudy with scattered light snow showers. Light to occasionally moderate E winds at Pass level.
Thursday Mostly cloudy with scattered light snow showers. Light to occasionally moderate E winds at Pass level.
Wednesday Night Mostly cloudy with scattered light rain or snow showers.
Thursday Mostly cloudy with scattered light rain or snow showers.
Wednesday Night Mostly cloudy with scattered light snow showers.
Thursday Mostly cloudy with scattered light snow showers.
Wednesday Night Mostly cloudy with scattered light snow showers.
Thursday Mostly cloudy with scattered light snow showers.
Wednesday Night Mostly cloudy with scattered light snow showers.
Thursday Mostly cloudy with scattered light snow showers.
Wednesday Night Cloudy with occasional light rain or snow showers.
Thursday Cloudy with occasional light rain or snow showers.

Issued: 2:07 PM PST Wednesday, November 20, 2024

Precipitation (in)

Wednesday Night Thursday Thursday Night Friday
4 pm - 4 am 4 am - 4 pm 4 pm - 4 am 4 am - 4 pm
Hurricane Ridge 0.25 LT 0.25 LT 0.10 LT 0.25
Mt Baker Ski Area LT 0.25 LT 0.10 LT 0.25 0.25 - 0.50
Mt. Loop - Barlow Pass LT 0.10 LT 0.10 LT 0.25 0.25 - 0.50
Stevens Pass LT 0.10 LT 0.10 LT 0.25 0.25 - 0.50
Snoqualmie Pass LT 0.10 LT 0.10 0.25 0.25 - 0.50
Crystal Mt LT 0.10 LT 0.10 0.25 - 0.50 0.25 - 0.50
Paradise LT 0.25 LT 0.10 0.25 - 0.50 0.50
White Pass LT 0.10 LT 0.10 0.25 - 0.50 0.25 - 0.50
Washington Pass LT 0.10 LT 0.10 LT 0.25 0.25 - 0.50
Mission Ridge LT 0.10 LT 0.10 0.25 - 0.50 0.25 - 0.50
Salmon la Sac - Gallagher Head LT 0.10 LT 0.10 0.25 0.25 - 0.50
Tieton River - Darland Mt. LT 0.10 LT 0.10 0.50 0.25 - 0.50
Mt Hood Meadows LT 0.25 LT 0.10 0.50 - 0.75 0.50
Timberline 0.25 LT 0.25 0.50 - 0.75 0.50
Hurricane Ridge Precipitation (in)
Wednesday Night 0.25
Thursday LT 0.25
Thursday Night LT 0.10
Friday LT 0.25
Mt Baker Ski Area Precipitation (in)
Wednesday Night LT 0.25
Thursday LT 0.10
Thursday Night LT 0.25
Friday 0.25 - 0.50
Mt. Loop - Barlow Pass Precipitation (in)
Wednesday Night LT 0.10
Thursday LT 0.10
Thursday Night LT 0.25
Friday 0.25 - 0.50
Stevens Pass Precipitation (in)
Wednesday Night LT 0.10
Thursday LT 0.10
Thursday Night LT 0.25
Friday 0.25 - 0.50
Snoqualmie Pass Precipitation (in)
Wednesday Night LT 0.10
Thursday LT 0.10
Thursday Night 0.25
Friday 0.25 - 0.50
Crystal Mt Precipitation (in)
Wednesday Night LT 0.10
Thursday LT 0.10
Thursday Night 0.25 - 0.50
Friday 0.25 - 0.50
Paradise Precipitation (in)
Wednesday Night LT 0.25
Thursday LT 0.10
Thursday Night 0.25 - 0.50
Friday 0.50
White Pass Precipitation (in)
Wednesday Night LT 0.10
Thursday LT 0.10
Thursday Night 0.25 - 0.50
Friday 0.25 - 0.50
Washington Pass Precipitation (in)
Wednesday Night LT 0.10
Thursday LT 0.10
Thursday Night LT 0.25
Friday 0.25 - 0.50
Mission Ridge Precipitation (in)
Wednesday Night LT 0.10
Thursday LT 0.10
Thursday Night 0.25 - 0.50
Friday 0.25 - 0.50
Salmon la Sac - Gallagher Head Precipitation (in)
Wednesday Night LT 0.10
Thursday LT 0.10
Thursday Night 0.25
Friday 0.25 - 0.50
Tieton River - Darland Mt. Precipitation (in)
Wednesday Night LT 0.10
Thursday LT 0.10
Thursday Night 0.50
Friday 0.25 - 0.50
Mt Hood Meadows Precipitation (in)
Wednesday Night LT 0.25
Thursday LT 0.10
Thursday Night 0.50 - 0.75
Friday 0.50
Timberline Precipitation (in)
Wednesday Night 0.25
Thursday LT 0.25
Thursday Night 0.50 - 0.75
Friday 0.50

Issued: 2:07 PM PST Wednesday, November 20, 2024

Snow Level (ft)

Wednesday Evening* Wednesday Night* Thursday Morning* Thursday Afternoon* Thursday Evening* Thursday Night* Friday Morning* Friday Afternoon*
Olympics 3500' 4000' 4500' 4500' 4000' 4000' 5000' 4500'
West North 3000' 3000' 3500' 4000' 3500' 3500' 3500' 4500'
West Central 3000' 3500' 3500' 4000' 3500' 3500' 3500' 4500'
West South 3000' 3000' 4000' 4500' 3500' 3500' 4000' 5000'
Stevens Pass 2500' 2000' 3000' 3500' 3000' 2000' 3000' 4500'
Snoqualmie Pass 3000' 3000' 3500' 4000' 3000' 3000' 3500' 4500'
East North 2000' 1500' 2000' 3500' 3000' 1500' 3500' 4000'
East Central 2500' 2000' 2500' 3500' 2500' 2000' 3500' 4000'
East South 3000' 2500' 3000' 4000' 3500' 3000' 4000' 5000'
Mt. Hood 4000' 4000' 4000' 4500' 5000' 7500' 7500' 5000'
Olympics Elevation
Wednesday Evening* 3500'
Wednesday Night* 4000'
Thursday Morning* 4500'
Thursday Afternoon* 4500'
Thursday Evening* 4000'
Thursday Night* 4000'
Friday Morning* 5000'
Friday Afternoon* 4500'
West North Elevation
Wednesday Evening* 3000'
Wednesday Night* 3000'
Thursday Morning* 3500'
Thursday Afternoon* 4000'
Thursday Evening* 3500'
Thursday Night* 3500'
Friday Morning* 3500'
Friday Afternoon* 4500'
West Central Elevation
Wednesday Evening* 3000'
Wednesday Night* 3500'
Thursday Morning* 3500'
Thursday Afternoon* 4000'
Thursday Evening* 3500'
Thursday Night* 3500'
Friday Morning* 3500'
Friday Afternoon* 4500'
West South Elevation
Wednesday Evening* 3000'
Wednesday Night* 3000'
Thursday Morning* 4000'
Thursday Afternoon* 4500'
Thursday Evening* 3500'
Thursday Night* 3500'
Friday Morning* 4000'
Friday Afternoon* 5000'
Stevens Pass Elevation
Wednesday Evening* 2500'
Wednesday Night* 2000'
Thursday Morning* 3000'
Thursday Afternoon* 3500'
Thursday Evening* 3000'
Thursday Night* 2000'
Friday Morning* 3000'
Friday Afternoon* 4500'
Snoqualmie Pass Elevation
Wednesday Evening* 3000'
Wednesday Night* 3000'
Thursday Morning* 3500'
Thursday Afternoon* 4000'
Thursday Evening* 3000'
Thursday Night* 3000'
Friday Morning* 3500'
Friday Afternoon* 4500'
East North Elevation
Wednesday Evening* 2000'
Wednesday Night* 1500'
Thursday Morning* 2000'
Thursday Afternoon* 3500'
Thursday Evening* 3000'
Thursday Night* 1500'
Friday Morning* 3500'
Friday Afternoon* 4000'
East Central Elevation
Wednesday Evening* 2500'
Wednesday Night* 2000'
Thursday Morning* 2500'
Thursday Afternoon* 3500'
Thursday Evening* 2500'
Thursday Night* 2000'
Friday Morning* 3500'
Friday Afternoon* 4000'
East South Elevation
Wednesday Evening* 3000'
Wednesday Night* 2500'
Thursday Morning* 3000'
Thursday Afternoon* 4000'
Thursday Evening* 3500'
Thursday Night* 3000'
Friday Morning* 4000'
Friday Afternoon* 5000'
Mt. Hood Elevation
Wednesday Evening* 4000'
Wednesday Night* 4000'
Thursday Morning* 4000'
Thursday Afternoon* 4500'
Thursday Evening* 5000'
Thursday Night* 7500'
Friday Morning* 7500'
Friday Afternoon* 5000'

Issued: 2:07 PM PST Wednesday, November 20, 2024

5000' Temperatures (°F)

Wednesday Night Thursday
Max / Min Max / Min
Olympics 27 / 24 31 / 23
West North 26 / 22 31 / 21
West Central 25 / 20 30 / 22
West South 27 / 22 33 / 22
Stevens Pass 25 / 21 30 / 22
Snoqualmie Pass 26 / 24 29 / 24
East North 24 / 19 28 / 20
East Central 27 / 23 29 / 21
East South 27 / 24 32 / 26
Mt. Hood 29 / 26 35 / 29
Olympics 5000' Temperature Forecast
(Max / Min)
Wednesday Night 27 / 24
Thursday 31 / 23
West North 5000' Temperature Forecast
(Max / Min)
Wednesday Night 26 / 22
Thursday 31 / 21
West Central 5000' Temperature Forecast
(Max / Min)
Wednesday Night 25 / 20
Thursday 30 / 22
West South 5000' Temperature Forecast
(Max / Min)
Wednesday Night 27 / 22
Thursday 33 / 22
Stevens Pass 5000' Temperature Forecast
(Max / Min)
Wednesday Night 25 / 21
Thursday 30 / 22
Snoqualmie Pass 5000' Temperature Forecast
(Max / Min)
Wednesday Night 26 / 24
Thursday 29 / 24
East North 5000' Temperature Forecast
(Max / Min)
Wednesday Night 24 / 19
Thursday 28 / 20
East Central 5000' Temperature Forecast
(Max / Min)
Wednesday Night 27 / 23
Thursday 29 / 21
East South 5000' Temperature Forecast
(Max / Min)
Wednesday Night 27 / 24
Thursday 32 / 26
Mt. Hood 5000' Temperature Forecast
(Max / Min)
Wednesday Night 29 / 26
Thursday 35 / 29

Issued: 2:07 PM PST Wednesday, November 20, 2024

Ridgeline Winds (mph)

Wednesday Evening Wednesday Night Thursday Morning Thursday Afternoon
Olympics SSW 10-20 S 5-15 SE 5-15 SSE 5-15
West North SSE 5-15 S 5-15 ESE 0-10 SE 5-15
West Central SE 5-15 SE 5-15 ESE 10-20 SE 5-15
West South S 5-15 SSE 5-15 ESE 5-15 SSE 10-20
Stevens Pass SSE 0-10 SSE 5-15 ESE 5-15 ESE 5-15
Snoqualmie Pass ESE 5-15 ESE 5-15 ESE 10-20 ESE 10-20
East North SSE 5-15 SSE 0-10 ESE 5-15 ESE 5-15
East Central S 5-15 SSE 5-15 SE 10-20 SE 10-20
East South SSW 5-15 SSE 0-10 SE 5-15 SSE 5-15
Mt. Hood SSW 5-15 SSW 5-15 SSE 10-20 SW 15-25
Olympics Ridgeline Winds (mph)
Wednesday Evening SSW 10-20
Wednesday Night S 5-15
Thursday Morning SE 5-15
Thursday Afternoon SSE 5-15
West North Ridgeline Winds (mph)
Wednesday Evening SSE 5-15
Wednesday Night S 5-15
Thursday Morning ESE 0-10
Thursday Afternoon SE 5-15
West Central Ridgeline Winds (mph)
Wednesday Evening SE 5-15
Wednesday Night SE 5-15
Thursday Morning ESE 10-20
Thursday Afternoon SE 5-15
West South Ridgeline Winds (mph)
Wednesday Evening S 5-15
Wednesday Night SSE 5-15
Thursday Morning ESE 5-15
Thursday Afternoon SSE 10-20
Stevens Pass Ridgeline Winds (mph)
Wednesday Evening SSE 0-10
Wednesday Night SSE 5-15
Thursday Morning ESE 5-15
Thursday Afternoon ESE 5-15
Snoqualmie Pass Ridgeline Winds (mph)
Wednesday Evening ESE 5-15
Wednesday Night ESE 5-15
Thursday Morning ESE 10-20
Thursday Afternoon ESE 10-20
East North Ridgeline Winds (mph)
Wednesday Evening SSE 5-15
Wednesday Night SSE 0-10
Thursday Morning ESE 5-15
Thursday Afternoon ESE 5-15
East Central Ridgeline Winds (mph)
Wednesday Evening S 5-15
Wednesday Night SSE 5-15
Thursday Morning SE 10-20
Thursday Afternoon SE 10-20
East South Ridgeline Winds (mph)
Wednesday Evening SSW 5-15
Wednesday Night SSE 0-10
Thursday Morning SE 5-15
Thursday Afternoon SSE 5-15
Mt. Hood Ridgeline Winds (mph)
Wednesday Evening SSW 5-15
Wednesday Night SSW 5-15
Thursday Morning SSE 10-20
Thursday Afternoon SW 15-25

Issued: 2:07 PM PST Wednesday, November 20, 2024

Extended Weather Synopsis

A rather ho-hum pattern will take hold over the weekend with an upper trough offshore spinning a few showers and over the area.  Showers will be more frequent and intense over the Olympic peninsula. Snow levels will remain between 2500-3500' over the weekend. 

 

 

Extended Snow Level (ft)

Friday Night* Saturday * Saturday Night* Sunday *
West North 3000' 3000' 2500' 3000'
Snoqualmie Pass 3500' 3500' 3000' 3000'
Mt. Hood 3500' 3500' 3500' 3500'
West North Elevation
Friday Night* 3000'
Saturday * 3000'
Saturday Night* 2500'
Sunday * 3000'
Snoqualmie Pass Elevation
Friday Night* 3500'
Saturday * 3500'
Saturday Night* 3000'
Sunday * 3000'
Mt. Hood Elevation
Friday Night* 3500'
Saturday * 3500'
Saturday Night* 3500'
Sunday * 3500'

Jump to: Weather Forecast I Precipitation I Snow Level I 5000' Temps I Ridgeline Winds I Extended Weather

Previous forecast from Nov 19, 2024

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.

The 5000’ temperature forecast does not imply a trend over the 12 hr period and only represents the max and min temperatures within a 12 hr period in the zone. The 6-hr snow level forecast, the forecast discussion, and weather forecast sections may add detail regarding temperature trends.

The snow level forecast represents the general snow level over a 6 hr time period. Freezing levels are forecast when precipitation is not expected.

*Easterly or offshore flow is highlighted with an asterisk when we expect relatively cool east winds in the major Cascade Passes. Easterly flow will often lead to temperature inversions and is a key variable for forecasting precipitation type in the Cascade Passes. Strong easterly flow events can affect terrain on a more regional scale.

Ridgeline winds are the average wind speed and direction over a 6 hr time period.

The wind forecast represents an elevation range instead of a single elevation slice. The elevation range overlaps with the near and above treeline elevation bands in the avalanche forecast and differs per zone.

Wind direction indicates the direction the wind originates or comes from on the 16-point compass rose.

Water Equivalent (WE) is the liquid water equivalent of all precipitation types; rain, snow, ice pellets, etc., forecast to the hundredth of an inch at specific locations. To use WE as a proxy for snowfall amounts, start with a snow to water ratio of 10:1 (10 inches of snow = 1 inch WE). Temperatures at or near freezing will generally have a lower ratio (heavy wet snow) and very cold temperatures can have a much higher ratio (dry fluffy snow).

The label LT, is shorthand for ‘less than’.