Issued: 2:40 PM PST Saturday, December 28, 2024
by Robert Hahn

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

Weather Synopsis

An active weather pattern continues through the weekend, but the focus of the storm track shifts away from our region Sunday night and Monday.

Rain and snow showers taper across the Cascades west slopes and passes Saturday evening as a weakening low pressure center moves across southern British Columbia. A well-defined convergence band should target the Skagit Valley area with some spillover to Washington Pass. These areas could pick up a quick 2-5" of snow. Temperatures gradually cool overnight, but don't expect much clearing as clouds are already spreading into the region ahead of the next system Saturday afternoon.

This system involves the formation of a surface low-pressure center off the Oregon coast overnight. A warm front lifts a band of moderate to heavy snowfall into Mt Hood and the southern Cascade Volcanoes with lighter precipitation extending into the central Cascades after midnight. The surface low moves over NW Oregon by mid-morning on Monday. The warm front continues to gradually lift northward, but the moderate to heavy precipitation likely remains south of I-90 in the morning and south of the mountain loop in the afternoon. The most impactful weather may involve a strong push of W winds targeting Mt Hood and the southern Washington volcanoes late in the day along with heavy mountain-induced precipitation.

An incoming trough brings cooler air into the region and kicks the frontal system eastward. Moderate to heavy precipitation and moderate to strong winds lift northward Sunday night with precipitation mostly targeting the west slopes of the Cascades. Increasingly light snow showers continue on Monday with decreasing moderate winds for ridgelines near and east of the mountain gaps.

 

 

 

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
Saturday Night Light rain and snow showers decrease or end overnight.
Sunday Light rain and snow develop in the morning and become moderate in the afternoon.
Saturday Night Mostly light rain and snow showers (moderate in convergence over the Skagit) decrease and end overnight.
Sunday Periods of light snow spread into the area from late morning onwards.
Saturday Night Mostly light rain and snow showers (moderate in convergence over the Skagit) decrease and end overnight. Moderate ridgeline winds quickly taper in the evening hours.
Sunday Light to moderate snow develops in the morning, spreading as it intensifies from south to north.
Saturday Night Decreasing light rain and snow showers in the evening. Then light snow develops overnight, potentially becoming moderate for Mt St Helens and Mt Adams.
Sunday Moderate to heavy rain and snow. Moderate ridgeline winds develop in the afternoon.
Saturday Night Decreasing light rain and snow showers. Rapidly decreasing moderate ridgeline winds become light. Mostly light W wind switches E overnight.
Sunday Increasing light snow may become moderate in the afternoon. Light ridgeline and E wind at the Pass.
Saturday Night Decreasing light rain and snow showers. Moderate ridgeline winds become light. Rapidly decreasing moderate ridgeline winds become light. Mostly light W wind switches E overnight.
Sunday Increasing light snow becomes moderate from late morning onward. Light ridgeline and E wind at the Pass.
Saturday Night Decreasing light rain and snow showers mainly near the Cascade Crest. Decreasing moderate ridgeline winds become light.
Sunday Cloudy with increasing light snow from mid-morning onward.
Saturday Night Decreasing light rain and snow showers mainly near the Cascade Crest. Decreasing moderate ridgeline winds become light.
Sunday Increasing light to moderate rain and snow.
Saturday Night Decreasing light rain and snow showers mainly near the Cascade Crest in the evening, then light snow develops overnight. Decreasing moderate ridgeline winds become light.
Sunday Increasing light to moderate rain and snow. Moderate ridgeline winds develop in the afternoon.
Saturday Night Light snow showers early, then light to moderate rain and snow develop overnight. Moderate ridgeline winds become light.
Sunday Heavy rain and snow. Moderate ridgeline winds become strong, and possibly extreme late in the day.

Issued: 2:40 PM PST Saturday, December 28, 2024

Precipitation (in)

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

Issued: 2:40 PM PST Saturday, December 28, 2024

Snow Level (ft)

Saturday Evening Saturday Night* Sunday Morning* Sunday Afternoon* Sunday Evening Sunday Night Monday Morning Monday Afternoon
Olympics 3500' 3000' 3000' 3000' 2500' 2000' 2000' 2500'
West North 3500' 3000' 2500' 3000' 2500' 2000' 2000' 2000'
West Central 3500' 3000' 2500' 3000' 2500' 2000' 2500' 2500'
West South 4000' 3000' 3000' 3500' 2500' 2000' 2500' 2500'
Stevens Pass 3500' 3000' 2500' 3000' 2500' 2000' 2500' 2500'
Snoqualmie Pass 3500' 3000' 2500' 3000' 2500' 2000' 2500' 2500'
East North 3000' 2500' 2000' 3000' 2500' 2000' 2000' 2500'
East Central 3500' 3000' 2500' 3000' 2500' 2000' 2500' 2500'
East South 4000' 3500' 3000' 3500' 2500' 2000' 2500' 2500'
Mt. Hood 4000' 4000' 4000' 3500' 2500' 2500' 2500' 2500'
Olympics Elevation
Saturday Evening 3500'
Saturday Night* 3000'
Sunday Morning* 3000'
Sunday Afternoon* 3000'
Sunday Evening 2500'
Sunday Night 2000'
Monday Morning 2000'
Monday Afternoon 2500'
West North Elevation
Saturday Evening 3500'
Saturday Night* 3000'
Sunday Morning* 2500'
Sunday Afternoon* 3000'
Sunday Evening 2500'
Sunday Night 2000'
Monday Morning 2000'
Monday Afternoon 2000'
West Central Elevation
Saturday Evening 3500'
Saturday Night* 3000'
Sunday Morning* 2500'
Sunday Afternoon* 3000'
Sunday Evening 2500'
Sunday Night 2000'
Monday Morning 2500'
Monday Afternoon 2500'
West South Elevation
Saturday Evening 4000'
Saturday Night* 3000'
Sunday Morning* 3000'
Sunday Afternoon* 3500'
Sunday Evening 2500'
Sunday Night 2000'
Monday Morning 2500'
Monday Afternoon 2500'
Stevens Pass Elevation
Saturday Evening 3500'
Saturday Night* 3000'
Sunday Morning* 2500'
Sunday Afternoon* 3000'
Sunday Evening 2500'
Sunday Night 2000'
Monday Morning 2500'
Monday Afternoon 2500'
Snoqualmie Pass Elevation
Saturday Evening 3500'
Saturday Night* 3000'
Sunday Morning* 2500'
Sunday Afternoon* 3000'
Sunday Evening 2500'
Sunday Night 2000'
Monday Morning 2500'
Monday Afternoon 2500'
East North Elevation
Saturday Evening 3000'
Saturday Night* 2500'
Sunday Morning* 2000'
Sunday Afternoon* 3000'
Sunday Evening 2500'
Sunday Night 2000'
Monday Morning 2000'
Monday Afternoon 2500'
East Central Elevation
Saturday Evening 3500'
Saturday Night* 3000'
Sunday Morning* 2500'
Sunday Afternoon* 3000'
Sunday Evening 2500'
Sunday Night 2000'
Monday Morning 2500'
Monday Afternoon 2500'
East South Elevation
Saturday Evening 4000'
Saturday Night* 3500'
Sunday Morning* 3000'
Sunday Afternoon* 3500'
Sunday Evening 2500'
Sunday Night 2000'
Monday Morning 2500'
Monday Afternoon 2500'
Mt. Hood Elevation
Saturday Evening 4000'
Saturday Night* 4000'
Sunday Morning* 4000'
Sunday Afternoon* 3500'
Sunday Evening 2500'
Sunday Night 2500'
Monday Morning 2500'
Monday Afternoon 2500'

Issued: 2:40 PM PST Saturday, December 28, 2024

5000' Temperatures (°F)

Saturday Night Sunday
Max / Min Max / Min
Olympics 29 / 26 28 / 26
West North 29 / 26 28 / 26
West Central 29 / 26 28 / 26
West South 30 / 27 29 / 26
Stevens Pass 29 / 27 29 / 26
Snoqualmie Pass 29 / 27 29 / 26
East North 28 / 23 27 / 22
East Central 29 / 26 29 / 27
East South 29 / 26 29 / 27
Mt. Hood 31 / 28 30 / 27
Olympics 5000' Temperature Forecast
(Max / Min)
Saturday Night 29 / 26
Sunday 28 / 26
West North 5000' Temperature Forecast
(Max / Min)
Saturday Night 29 / 26
Sunday 28 / 26
West Central 5000' Temperature Forecast
(Max / Min)
Saturday Night 29 / 26
Sunday 28 / 26
West South 5000' Temperature Forecast
(Max / Min)
Saturday Night 30 / 27
Sunday 29 / 26
Stevens Pass 5000' Temperature Forecast
(Max / Min)
Saturday Night 29 / 27
Sunday 29 / 26
Snoqualmie Pass 5000' Temperature Forecast
(Max / Min)
Saturday Night 29 / 27
Sunday 29 / 26
East North 5000' Temperature Forecast
(Max / Min)
Saturday Night 28 / 23
Sunday 27 / 22
East Central 5000' Temperature Forecast
(Max / Min)
Saturday Night 29 / 26
Sunday 29 / 27
East South 5000' Temperature Forecast
(Max / Min)
Saturday Night 29 / 26
Sunday 29 / 27
Mt. Hood 5000' Temperature Forecast
(Max / Min)
Saturday Night 31 / 28
Sunday 30 / 27

Issued: 2:40 PM PST Saturday, December 28, 2024

Ridgeline Winds (mph)

Saturday Evening Saturday Night Sunday Morning Sunday Afternoon
Olympics WSW 5-15 SSE 0-10 E 5-15 ESE 5-15
West North WSW 10-20 VAR 0-10 E 0-10 E 5-15
West Central WSW 10-20 VAR 0-10 E 5-15 ESE 5-15
West South W 15-25 SE 0-10 ESE 5-15 SSW 15-25
Stevens Pass WSW 15-25 ESE 0-10 E 5-15 ESE 10-20
Snoqualmie Pass W 15-25 SSE 5-15 E 5-15 ESE 10-20
East North WSW 15-25 VAR 0-10 E 5-15 E 5-15
East Central W 20-30 VAR 0-10 E 5-15 ESE 5-15
East South W 15-25 SSE 0-10 E 5-15 SW 15-25
Mt. Hood WSW 15-25 SE 5-15 WSW 10-20 WSW 25-35
Olympics Ridgeline Winds (mph)
Saturday Evening WSW 5-15
Saturday Night SSE 0-10
Sunday Morning E 5-15
Sunday Afternoon ESE 5-15
West North Ridgeline Winds (mph)
Saturday Evening WSW 10-20
Saturday Night VAR 0-10
Sunday Morning E 0-10
Sunday Afternoon E 5-15
West Central Ridgeline Winds (mph)
Saturday Evening WSW 10-20
Saturday Night VAR 0-10
Sunday Morning E 5-15
Sunday Afternoon ESE 5-15
West South Ridgeline Winds (mph)
Saturday Evening W 15-25
Saturday Night SE 0-10
Sunday Morning ESE 5-15
Sunday Afternoon SSW 15-25
Stevens Pass Ridgeline Winds (mph)
Saturday Evening WSW 15-25
Saturday Night ESE 0-10
Sunday Morning E 5-15
Sunday Afternoon ESE 10-20
Snoqualmie Pass Ridgeline Winds (mph)
Saturday Evening W 15-25
Saturday Night SSE 5-15
Sunday Morning E 5-15
Sunday Afternoon ESE 10-20
East North Ridgeline Winds (mph)
Saturday Evening WSW 15-25
Saturday Night VAR 0-10
Sunday Morning E 5-15
Sunday Afternoon E 5-15
East Central Ridgeline Winds (mph)
Saturday Evening W 20-30
Saturday Night VAR 0-10
Sunday Morning E 5-15
Sunday Afternoon ESE 5-15
East South Ridgeline Winds (mph)
Saturday Evening W 15-25
Saturday Night SSE 0-10
Sunday Morning E 5-15
Sunday Afternoon SW 15-25
Mt. Hood Ridgeline Winds (mph)
Saturday Evening WSW 15-25
Saturday Night SE 5-15
Sunday Morning WSW 10-20
Sunday Afternoon WSW 25-35

Issued: 2:40 PM PST Saturday, December 28, 2024

Extended Weather Synopsis

A shortwave ridge replaces a weak trough Monday night, limiting any very light snow showers to areas near the Canadian border. The ridge shifts eastward on Tuesday for a mostly dry day. A well-developed frontal system approaches Tuesday night and brings stormy weather on Wednesday with a period of strong S winds before the frontal passage. With cold air in place, this system should be mostly snow for the mountains.

Extended Snow Level (ft)

Monday Night Tuesday * Tuesday Night* Wednesday *
West North 2000' 1500' 1500' 2000'
Snoqualmie Pass 2500' 2000' 1500' 2000'
Mt. Hood 2500' 3000' 2500' 3000'
West North Elevation
Monday Night 2000'
Tuesday * 1500'
Tuesday Night* 1500'
Wednesday * 2000'
Snoqualmie Pass Elevation
Monday Night 2500'
Tuesday * 2000'
Tuesday Night* 1500'
Wednesday * 2000'
Mt. Hood Elevation
Monday Night 2500'
Tuesday * 3000'
Tuesday Night* 2500'
Wednesday * 3000'

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

Previous forecast from Dec 28, 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’.