Issued: 6:58 AM PST Sunday, December 15, 2024
by Dallas Glass

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

Weather Synopsis

Our last storm is finally exiting the region this morning. Showers continue to linger mainly along the west slopes of the Cascades and Olympics. These should draw to a close as a transient high pressure ridge quickly traverses the region. Expect showers to hang on the longest near the Canadian border. 

After a rather cloudy start to the day, most location should start to see some sun breaks. Areas east of the crest and further south will have the best chance at significant sunshine. It won't last long though. High clouds should start to push in from the SW this afternoon. It could be a race between clearing low clouds and incoming high clouds for how much sunshine any specific location actually sees. 

The next storm starts to arrive overnight with precipitation pushing into the southern Olympics, Mount Saint Helens, and Hood areas in the evening. Snow will spread from S to North mainly impacting locations near and south of I-90. Showers should just start to reach the central and northern Cascades in the very early morning hours. With S-SE flow, this system will bring another shot of snow to the east side forecast zone. Most of the precipitation occurs before lunchtime on Monday, shifting to a more showery pattern in the afternoon. 

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 Snow showers mainly in the early morning, then clearing. High thin clouds in the afternoon.
Sunday Night Clouds increasing with snow starting in the evening for the southern Olympics and overnight near Hurricane Ridge. S winds becoming moderate but gusty.
Sunday Snow showers, heaviest in the morning. A few sun breaks possible in the afternoon. Light to moderate SW winds decreasing.
Sunday Night Clearing with low clouds and fog in the evening. Then increasing clouds and a few isolated showers in the early morning hours. SSE winds becoming light to moderate.
Sunday Snow showers mainly in the morning. Sun breaks possible in the afternoon with isolated showers. Light to moderate SW winds decreasing.
Sunday Night Dry in the evening with some low clouds and valley fog. Clouds increasing overnight with a few showers in the early morning hours. Winds turning SE and becoming moderate.
Sunday Cloudy to mostly cloudy with snow showers. Low clouds with sun breaks in the afternoon. High clouds increasing late in the day. Light to moderate WSW winds decreasing.
Sunday Night Clouds increasing in the evening with showers arriving near Mount Saint Helens and spreading NE overnight. SE winds becoming moderate.
Sunday Cloudy with snow showers mainly in the morning. Sun breaks with lingering low clouds in the afternoon. Westerly flow at pass level.
Sunday Night Increasing clouds in the evening, with a few showers arriving in the early morning hours. SE ridgeline winds becoming light to moderate with light to moderate east flow at pass level.
Sunday Cloudy with snow showers mainly in the morning. A few sun breaks in the afternoon with increasing high clouds. Light to moderate W ridgeline winds decreasing. Light westerly flow at pass level.
Sunday Night Cloudy with snow returning around midnight. ESE ridgeline winds becoming moderate but gusty. Light to moderate E flow at pass level.
Sunday Partly to mostly cloudy in the morning with a few isolated showers. Clearing. Light to moderate W winds decreasing.
Sunday Night Clouds increasing in the evening and overnight. A few showers mainly in the southern and eastern parts of the zone. Winds becoming SSE light to moderate.
Sunday Partly cloudy to mostly clear with a few showers near the crest in the morning. Mostly sunny with increasing high clouds in the afternoon. Moderate W winds decreasing.
Sunday Night Cloudy with snow arriving around midnight. Winds becoming SSE moderate and gusty.
Sunday Partly cloudy to mostly sunny with a few isolated showers possible near the crest in the morning. Becoming mostly sunny with high clouds increasing in the afternoon.
Sunday Night Cloudy with snow arriving overnight. Winds becoming SSW moderate and gusty.
Sunday Cloudy with snow showers mainly in the morning. Some sun breaks possible in the afternoon. Moderate to strong W winds decreasing.
Sunday Night Cloudy with snow returning in the evening. S winds becoming SW moderate to strong and gusty.

Precipitation (in)

Sunday Sunday Night Monday
4 am - 4 pm 4 pm - 4 am 4 am - 4 pm
Hurricane Ridge LT 0.10 LT 0.25 0.25
Mt Baker Ski Area LT 0.25 LT 0.10 0.50
Mt. Loop - Barlow Pass LT 0.25 LT 0.10 0.25 - 0.50
Stevens Pass LT 0.25 LT 0.10 0.25
Snoqualmie Pass LT 0.25 LT 0.25 0.25 - 0.50
Crystal Mt LT 0.10 0.25 0.25 - 0.50
Paradise LT 0.25 0.25 - 0.50 0.50
White Pass LT 0.10 0.25 0.25
Washington Pass LT 0.10 LT 0.10 LT 0.25
Mission Ridge 0 LT 0.25 0.25
Salmon la Sac - Gallagher Head LT 0.10 LT 0.25 0.25
Tieton River - Darland Mt. LT 0.10 0.25 0.25
Mt Hood Meadows 0.25 - 0.50 0.75 -1.00 0.50 - 0.75
Timberline 0.25 - 0.50 0.75 -1.00 0.75
Hurricane Ridge Precipitation (in)
Sunday LT 0.10
Sunday Night LT 0.25
Monday 0.25
Mt Baker Ski Area Precipitation (in)
Sunday LT 0.25
Sunday Night LT 0.10
Monday 0.50
Mt. Loop - Barlow Pass Precipitation (in)
Sunday LT 0.25
Sunday Night LT 0.10
Monday 0.25 - 0.50
Stevens Pass Precipitation (in)
Sunday LT 0.25
Sunday Night LT 0.10
Monday 0.25
Snoqualmie Pass Precipitation (in)
Sunday LT 0.25
Sunday Night LT 0.25
Monday 0.25 - 0.50
Crystal Mt Precipitation (in)
Sunday LT 0.10
Sunday Night 0.25
Monday 0.25 - 0.50
Paradise Precipitation (in)
Sunday LT 0.25
Sunday Night 0.25 - 0.50
Monday 0.50
White Pass Precipitation (in)
Sunday LT 0.10
Sunday Night 0.25
Monday 0.25
Washington Pass Precipitation (in)
Sunday LT 0.10
Sunday Night LT 0.10
Monday LT 0.25
Mission Ridge Precipitation (in)
Sunday 0
Sunday Night LT 0.25
Monday 0.25
Salmon la Sac - Gallagher Head Precipitation (in)
Sunday LT 0.10
Sunday Night LT 0.25
Monday 0.25
Tieton River - Darland Mt. Precipitation (in)
Sunday LT 0.10
Sunday Night 0.25
Monday 0.25
Mt Hood Meadows Precipitation (in)
Sunday 0.25 - 0.50
Sunday Night 0.75 -1.00
Monday 0.50 - 0.75
Timberline Precipitation (in)
Sunday 0.25 - 0.50
Sunday Night 0.75 -1.00
Monday 0.75

Snow Level (ft)

Sunday Morning Sunday Afternoon Sunday Evening* Sunday Night* Monday Morning* Monday Afternoon*
Olympics 2000' 2000' 2000' 2500' 3000' 3000'
West North 2000' 2000' 1500' 1500' 2000' 2500'
West Central 2000' 2000' 1500' 1500' 2000' 2500'
West South 2000' 2500' 2000' 2500' 3000' 3000'
Stevens Pass 2000' 2000' 1500' 2000' 2000' 2000'
Snoqualmie Pass 2000' 2500' 1500' 2000' 2000' 2500'
East North 1500' 2000' 1000' 1000' 1000' 1000'
East Central 1500' 2000' 1000' 1500' 1500' 2000'
East South 2000' 2500' 2500' 2500' 2500' 2500'
Mt. Hood 2500' 3000' 3000' 3500' 3500' 3500'
Olympics Elevation
Sunday Morning 2000'
Sunday Afternoon 2000'
Sunday Evening* 2000'
Sunday Night* 2500'
Monday Morning* 3000'
Monday Afternoon* 3000'
West North Elevation
Sunday Morning 2000'
Sunday Afternoon 2000'
Sunday Evening* 1500'
Sunday Night* 1500'
Monday Morning* 2000'
Monday Afternoon* 2500'
West Central Elevation
Sunday Morning 2000'
Sunday Afternoon 2000'
Sunday Evening* 1500'
Sunday Night* 1500'
Monday Morning* 2000'
Monday Afternoon* 2500'
West South Elevation
Sunday Morning 2000'
Sunday Afternoon 2500'
Sunday Evening* 2000'
Sunday Night* 2500'
Monday Morning* 3000'
Monday Afternoon* 3000'
Stevens Pass Elevation
Sunday Morning 2000'
Sunday Afternoon 2000'
Sunday Evening* 1500'
Sunday Night* 2000'
Monday Morning* 2000'
Monday Afternoon* 2000'
Snoqualmie Pass Elevation
Sunday Morning 2000'
Sunday Afternoon 2500'
Sunday Evening* 1500'
Sunday Night* 2000'
Monday Morning* 2000'
Monday Afternoon* 2500'
East North Elevation
Sunday Morning 1500'
Sunday Afternoon 2000'
Sunday Evening* 1000'
Sunday Night* 1000'
Monday Morning* 1000'
Monday Afternoon* 1000'
East Central Elevation
Sunday Morning 1500'
Sunday Afternoon 2000'
Sunday Evening* 1000'
Sunday Night* 1500'
Monday Morning* 1500'
Monday Afternoon* 2000'
East South Elevation
Sunday Morning 2000'
Sunday Afternoon 2500'
Sunday Evening* 2500'
Sunday Night* 2500'
Monday Morning* 2500'
Monday Afternoon* 2500'
Mt. Hood Elevation
Sunday Morning 2500'
Sunday Afternoon 3000'
Sunday Evening* 3000'
Sunday Night* 3500'
Monday Morning* 3500'
Monday Afternoon* 3500'

5000' Temperatures (°F)

Sunday Sunday Night
Max / Min Max / Min
Olympics 27 / 22 27 / 20
West North 26 / 22 27 / 20
West Central 28 / 23 28 / 20
West South 27 / 22 27 / 19
Stevens Pass 27 / 23 25 / 19
Snoqualmie Pass 26 / 23 26 / 20
East North 24 / 16 20 / 14
East Central 27 / 22 25 / 19
East South 27 / 23 25 / 19
Mt. Hood 28 / 24 29 / 26
Olympics 5000' Temperature Forecast
(Max / Min)
Sunday 27 / 22
Sunday Night 27 / 20
West North 5000' Temperature Forecast
(Max / Min)
Sunday 26 / 22
Sunday Night 27 / 20
West Central 5000' Temperature Forecast
(Max / Min)
Sunday 28 / 23
Sunday Night 28 / 20
West South 5000' Temperature Forecast
(Max / Min)
Sunday 27 / 22
Sunday Night 27 / 19
Stevens Pass 5000' Temperature Forecast
(Max / Min)
Sunday 27 / 23
Sunday Night 25 / 19
Snoqualmie Pass 5000' Temperature Forecast
(Max / Min)
Sunday 26 / 23
Sunday Night 26 / 20
East North 5000' Temperature Forecast
(Max / Min)
Sunday 24 / 16
Sunday Night 20 / 14
East Central 5000' Temperature Forecast
(Max / Min)
Sunday 27 / 22
Sunday Night 25 / 19
East South 5000' Temperature Forecast
(Max / Min)
Sunday 27 / 23
Sunday Night 25 / 19
Mt. Hood 5000' Temperature Forecast
(Max / Min)
Sunday 28 / 24
Sunday Night 29 / 26

Ridgeline Winds (mph)

Sunday Morning Sunday Afternoon Sunday Evening Sunday Night
Olympics SW 5-15 SSW 5-15 S 10-20 S 15-25
West North SW 10-20 SSW 5-15 SSE 5-15 SSE 10-20
West Central SW 10-20 SW 5-15 SSE 5-15 SE 15-25
West South WSW 10-20 SW 5-15 SSE 10-20 SE 15-25
Stevens Pass W 5-15 W 5-15 SE 5-15 SE 10-20
Snoqualmie Pass W 10-20 W 5-15 SE 10-20 SE 15-25
East North W 10-20 W 5-15 S 5-15 SSE 10-20
East Central W 15-25 W 10-20 S 10-20 SSE 15-25
East South W 10-20 W 5-15 S 10-20 SSE 15-25
Mt. Hood W 20-30 SW 10-20 S 10-20 SW 20-30
Olympics Ridgeline Winds (mph)
Sunday Morning SW 5-15
Sunday Afternoon SSW 5-15
Sunday Evening S 10-20
Sunday Night S 15-25
West North Ridgeline Winds (mph)
Sunday Morning SW 10-20
Sunday Afternoon SSW 5-15
Sunday Evening SSE 5-15
Sunday Night SSE 10-20
West Central Ridgeline Winds (mph)
Sunday Morning SW 10-20
Sunday Afternoon SW 5-15
Sunday Evening SSE 5-15
Sunday Night SE 15-25
West South Ridgeline Winds (mph)
Sunday Morning WSW 10-20
Sunday Afternoon SW 5-15
Sunday Evening SSE 10-20
Sunday Night SE 15-25
Stevens Pass Ridgeline Winds (mph)
Sunday Morning W 5-15
Sunday Afternoon W 5-15
Sunday Evening SE 5-15
Sunday Night SE 10-20
Snoqualmie Pass Ridgeline Winds (mph)
Sunday Morning W 10-20
Sunday Afternoon W 5-15
Sunday Evening SE 10-20
Sunday Night SE 15-25
East North Ridgeline Winds (mph)
Sunday Morning W 10-20
Sunday Afternoon W 5-15
Sunday Evening S 5-15
Sunday Night SSE 10-20
East Central Ridgeline Winds (mph)
Sunday Morning W 15-25
Sunday Afternoon W 10-20
Sunday Evening S 10-20
Sunday Night SSE 15-25
East South Ridgeline Winds (mph)
Sunday Morning W 10-20
Sunday Afternoon W 5-15
Sunday Evening S 10-20
Sunday Night SSE 15-25
Mt. Hood Ridgeline Winds (mph)
Sunday Morning W 20-30
Sunday Afternoon SW 10-20
Sunday Evening S 10-20
Sunday Night SW 20-30

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

Previous forecast from Dec 14, 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’.