Issued: 7:03 AM PST Sunday, December 10, 2023
by Robert Hahn

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

Weather Synopsis

The last in a series of atmospheric river events is in its final stages. A frontal band lingers over Oregon on Sunday as heavy rain and high-elevation snow continue for Mt Hood and the southernmost Washington Cascade volcanoes, gradually decreasing during the day. Further north, much of the precipitation for the 4 AM to 4 PM block has already fallen, but mostly light showers should continue particularly near and west of the Cascade Crest. Snow levels peak in the 5000-7000 ft range this morning in most areas, but Washington Pass and areas around Leavenworth continue to warm up as milder air from west of the Cascades continues to trickle in. Widespread freezing rain in the Cascades Passes should come to an end by 10 AM with freezing rain becoming increasingly isolated in areas further east as well.

A weak trough maintains the chances for very light showers near and west of the Cascade Crest Sunday night with partly cloudy skies further east. Snow levels lower to around 4000-4500 ft.

Expect mostly cloudy skies to continue Monday morning with isolated showers, but a developing offshore ridge dries us out in the afternoon with partly cloudy conditions across the region.

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
Sunday Light rain and high-elevation snow showers in the morning, decreasing or ending in the afternoon.
Sunday Night Mostly cloudy with an isolated rain or snow shower possible.
Sunday Light to moderate rain and snow showers becoming light by late morning.
Sunday Night Mostly cloudy with isolated rain and snow showers.
Sunday Light to moderate rain and snow showers becoming light by late morning.
Sunday Night Mostly cloudy with isolated rain and snow showers.
Sunday Moderate to heavy rain and high-elevation snow quickly taper to light to occasionally moderate rain and snow showers. Gradually decreasing moderate ridgeline winds.
Sunday Night Mostly cloudy with isolated rain and snow showers.
Sunday Decreasing light to moderate rain and high elevation snow showers with freezing rain possible through the morning hours at the Pass. Light ridgeline and E wind switching W at the Pass during the afternoon.
Sunday Night Mostly cloudy with isolated rain and snow showers. Light ridgeline and light W or variable winds at the Pass.
Sunday Decreasing moderate rain and high elevation snow showers with freezing rain possible early in the morning at the Pass. Moderate ridgeline winds. Moderate E winds decreasing and switching W at the Pass during the afternoon.
Sunday Night Mostly cloudy with isolated rain and snow showers. Light ridgeline and light W or variable winds at the Pass.
Sunday Light rain and snow showers. Gradually rising snow levels.
Sunday Night Partly cloudy with isolated rain and snow showers.
Sunday Decreasing light to moderate rain and snow showers near the Cascade Crest with lighter amounts further east. Freezing rain may continue but becomes limited to more isolated valley locations as the day progresses.
Sunday Night Partly cloudy with isolated rain and snow showers.
Sunday Light rain and snow showers, heaviest near the Cascade Crest.
Sunday Night Partly cloudy with isolated rain and snow showers.
Sunday Heavy rain and high-elevation snow decreasing in the afternoon. Moderate ridgeline winds.
Sunday Night Decreasing light to moderate rain and snow showers. Ridgeline winds becoming light.

Issued: 7:03 AM PST Sunday, December 10, 2023

Precipitation (in)

Sunday Sunday Night Monday
4 am - 4 pm 4 pm - 4 am 4 am - 4 pm
Hurricane Ridge LT 0.10 0 0
Mt Baker Ski Area 0.50 LT 0.10 LT 0.10
Mt. Loop - Barlow Pass LT 0.25 LT 0.10 LT 0.10
Stevens Pass 0.25 - 0.50 LT 0.10 LT 0.10
Snoqualmie Pass 0.50 - 0.75 LT 0.10 LT 0.10
Crystal Mt LT 0.25 LT 0.10 0
Paradise 0.75 LT 0.10 LT 0.10
White Pass 0.25 LT 0.10 LT 0.10
Washington Pass LT 0.10 LT 0.10 0
Mission Ridge LT 0.25 LT 0.10 0
Salmon la Sac - Gallagher Head 0.25 - 0.50 LT 0.10 0
Tieton River - Darland Mt. LT 0.25 LT 0.10 0
Mt Hood Meadows 1.50 0.25 LT 0.10
Timberline 1.50 0.25 LT 0.10
Hurricane Ridge Precipitation (in)
Sunday LT 0.10
Sunday Night 0
Monday 0
Mt Baker Ski Area Precipitation (in)
Sunday 0.50
Sunday Night LT 0.10
Monday LT 0.10
Mt. Loop - Barlow Pass Precipitation (in)
Sunday LT 0.25
Sunday Night LT 0.10
Monday LT 0.10
Stevens Pass Precipitation (in)
Sunday 0.25 - 0.50
Sunday Night LT 0.10
Monday LT 0.10
Snoqualmie Pass Precipitation (in)
Sunday 0.50 - 0.75
Sunday Night LT 0.10
Monday LT 0.10
Crystal Mt Precipitation (in)
Sunday LT 0.25
Sunday Night LT 0.10
Monday 0
Paradise Precipitation (in)
Sunday 0.75
Sunday Night LT 0.10
Monday LT 0.10
White Pass Precipitation (in)
Sunday 0.25
Sunday Night LT 0.10
Monday LT 0.10
Washington Pass Precipitation (in)
Sunday LT 0.10
Sunday Night LT 0.10
Monday 0
Mission Ridge Precipitation (in)
Sunday LT 0.25
Sunday Night LT 0.10
Monday 0
Salmon la Sac - Gallagher Head Precipitation (in)
Sunday 0.25 - 0.50
Sunday Night LT 0.10
Monday 0
Tieton River - Darland Mt. Precipitation (in)
Sunday LT 0.25
Sunday Night LT 0.10
Monday 0
Mt Hood Meadows Precipitation (in)
Sunday 1.50
Sunday Night 0.25
Monday LT 0.10
Timberline Precipitation (in)
Sunday 1.50
Sunday Night 0.25
Monday LT 0.10

Issued: 7:03 AM PST Sunday, December 10, 2023

Snow Level (ft)

Sunday Morning* Sunday Afternoon Sunday Evening Sunday Night Monday Morning Monday Afternoon*
Olympics 6500' 6000' 5000' 4000' 4000' 4500'
West North 5000' 5000' 5000' 4500' 4000' 500'
West Central 5500' 5500' 5000' 4500' 4000' 5000'
West South 6000' 6000' 5500' 5000' 4000' 5000'
Stevens Pass 5500' 5500' 5000' 4500' 4000' 4500'
Snoqualmie Pass 6000' 5500' 5500' 4500' 4000' 5000'
East North 3500' 4500' 4500' 4500' 4000' 4500'
East Central 4500' 5000' 5500' 4500' 4000' 4500'
East South 6000' 6000' 6000' 5000' 4000' 5000'
Mt. Hood 7000' 7000' 6500' 6000' 5500' 6000'
Olympics Elevation
Sunday Morning* 6500'
Sunday Afternoon 6000'
Sunday Evening 5000'
Sunday Night 4000'
Monday Morning 4000'
Monday Afternoon* 4500'
West North Elevation
Sunday Morning* 5000'
Sunday Afternoon 5000'
Sunday Evening 5000'
Sunday Night 4500'
Monday Morning 4000'
Monday Afternoon* 500'
West Central Elevation
Sunday Morning* 5500'
Sunday Afternoon 5500'
Sunday Evening 5000'
Sunday Night 4500'
Monday Morning 4000'
Monday Afternoon* 5000'
West South Elevation
Sunday Morning* 6000'
Sunday Afternoon 6000'
Sunday Evening 5500'
Sunday Night 5000'
Monday Morning 4000'
Monday Afternoon* 5000'
Stevens Pass Elevation
Sunday Morning* 5500'
Sunday Afternoon 5500'
Sunday Evening 5000'
Sunday Night 4500'
Monday Morning 4000'
Monday Afternoon* 4500'
Snoqualmie Pass Elevation
Sunday Morning* 6000'
Sunday Afternoon 5500'
Sunday Evening 5500'
Sunday Night 4500'
Monday Morning 4000'
Monday Afternoon* 5000'
East North Elevation
Sunday Morning* 3500'
Sunday Afternoon 4500'
Sunday Evening 4500'
Sunday Night 4500'
Monday Morning 4000'
Monday Afternoon* 4500'
East Central Elevation
Sunday Morning* 4500'
Sunday Afternoon 5000'
Sunday Evening 5500'
Sunday Night 4500'
Monday Morning 4000'
Monday Afternoon* 4500'
East South Elevation
Sunday Morning* 6000'
Sunday Afternoon 6000'
Sunday Evening 6000'
Sunday Night 5000'
Monday Morning 4000'
Monday Afternoon* 5000'
Mt. Hood Elevation
Sunday Morning* 7000'
Sunday Afternoon 7000'
Sunday Evening 6500'
Sunday Night 6000'
Monday Morning 5500'
Monday Afternoon* 6000'

Issued: 7:03 AM PST Sunday, December 10, 2023

5000' Temperatures (°F)

Sunday Sunday Night
Max / Min Max / Min
Olympics 38 / 32 30 / 25
West North 35 / 33 34 / 29
West Central 36 / 35 35 / 29
West South 37 / 33 34 / 28
Stevens Pass 36 / 35 35 / 30
Snoqualmie Pass 36 / 34 35 / 27
East North 34 / 28 33 / 29
East Central 36 / 33 34 / 28
East South 37 / 34 34 / 28
Mt. Hood 39 / 36 37 / 34
Olympics 5000' Temperature Forecast
(Max / Min)
Sunday 38 / 32
Sunday Night 30 / 25
West North 5000' Temperature Forecast
(Max / Min)
Sunday 35 / 33
Sunday Night 34 / 29
West Central 5000' Temperature Forecast
(Max / Min)
Sunday 36 / 35
Sunday Night 35 / 29
West South 5000' Temperature Forecast
(Max / Min)
Sunday 37 / 33
Sunday Night 34 / 28
Stevens Pass 5000' Temperature Forecast
(Max / Min)
Sunday 36 / 35
Sunday Night 35 / 30
Snoqualmie Pass 5000' Temperature Forecast
(Max / Min)
Sunday 36 / 34
Sunday Night 35 / 27
East North 5000' Temperature Forecast
(Max / Min)
Sunday 34 / 28
Sunday Night 33 / 29
East Central 5000' Temperature Forecast
(Max / Min)
Sunday 36 / 33
Sunday Night 34 / 28
East South 5000' Temperature Forecast
(Max / Min)
Sunday 37 / 34
Sunday Night 34 / 28
Mt. Hood 5000' Temperature Forecast
(Max / Min)
Sunday 39 / 36
Sunday Night 37 / 34

Issued: 7:03 AM PST Sunday, December 10, 2023

Ridgeline Winds (mph)

Sunday Morning Sunday Afternoon Sunday Evening Sunday Night
Olympics WSW 10-20 SW 5-15 SW 0-10 S 0-10
West North SW 5-15 SW 5-15 WSW 5-15 SW 0-10
West Central SW 10-20 SW 10-20 WSW 10-20 WSW 0-10
West South WSW 10-20 WSW 5-15 WSW 0-10 W 0-10
Stevens Pass WSW 5-15 WSW 10-20 W 5-15 W 0-10
Snoqualmie Pass W 10-20 W 10-20 W 5-15 W 5-15
East North WSW 10-20 WSW 10-20 WSW 10-20 WNW 5-15
East Central W 15-25 W 15-25 W 10-20 WNW 5-15
East South WSW 10-20 W 10-20 W 5-15 WNW 5-15
Mt. Hood WSW 15-25 WSW 15-25 WSW 10-20 WSW 10-20
Olympics Ridgeline Winds (mph)
Sunday Morning WSW 10-20
Sunday Afternoon SW 5-15
Sunday Evening SW 0-10
Sunday Night S 0-10
West North Ridgeline Winds (mph)
Sunday Morning SW 5-15
Sunday Afternoon SW 5-15
Sunday Evening WSW 5-15
Sunday Night SW 0-10
West Central Ridgeline Winds (mph)
Sunday Morning SW 10-20
Sunday Afternoon SW 10-20
Sunday Evening WSW 10-20
Sunday Night WSW 0-10
West South Ridgeline Winds (mph)
Sunday Morning WSW 10-20
Sunday Afternoon WSW 5-15
Sunday Evening WSW 0-10
Sunday Night W 0-10
Stevens Pass Ridgeline Winds (mph)
Sunday Morning WSW 5-15
Sunday Afternoon WSW 10-20
Sunday Evening W 5-15
Sunday Night W 0-10
Snoqualmie Pass Ridgeline Winds (mph)
Sunday Morning W 10-20
Sunday Afternoon W 10-20
Sunday Evening W 5-15
Sunday Night W 5-15
East North Ridgeline Winds (mph)
Sunday Morning WSW 10-20
Sunday Afternoon WSW 10-20
Sunday Evening WSW 10-20
Sunday Night WNW 5-15
East Central Ridgeline Winds (mph)
Sunday Morning W 15-25
Sunday Afternoon W 15-25
Sunday Evening W 10-20
Sunday Night WNW 5-15
East South Ridgeline Winds (mph)
Sunday Morning WSW 10-20
Sunday Afternoon W 10-20
Sunday Evening W 5-15
Sunday Night WNW 5-15
Mt. Hood Ridgeline Winds (mph)
Sunday Morning WSW 15-25
Sunday Afternoon WSW 15-25
Sunday Evening WSW 10-20
Sunday Night WSW 10-20

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

Previous forecast from Dec 9, 2023

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’.