Issued: 2:03 PM PST Saturday, December 30, 2023
by Dennis D'Amico

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

Weather Synopsis

A weakening frontal system is slowly marching inland this afternoon with showers rotating from south to north across the area. As has happened a few times this season, the southerly flow produced more rain and high elevation snow than expected to the northwest Cascades with lighter amounts elsewhere. We'll see this pattern continue through the evening as snow levels slowly lower to 5000' this afternoon and drop to 3500-4000' overnight. 

The upper level trough behind this frontal system will lift NE on Sunday morning. This should keep a few showers in the area mainly for the north Cascades. We'll see a drying and clearing trend on Sunday with more sunshine for the south Washington Cascades, Olympics and Mt Hood and a later or partial breakout further north. Freezing levels will be cooler than they have been but not cold for the last day of December, settling into the 4000-5000' range under light winds.

We may see some cloud cover NYE as a dry upper level trough swinds north of the area overnight. On New Year's Day, a ridge of high pressure will usher in 2024 with a dry forecast. Cool easterly flow will start to pick up on Monday. This should bring some low clouds along the east slopes of the Cascades and through the Cascade Passes with clearer and milder conditions further west of the Cascade crest. 

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 Mostly cloudy with scattered light rain and snow showers becoming isolated after midnight.
Sunday Partly cloudy in the morning becoming mostly sunny mid-day.
Saturday Night Light to moderate rain and snow showers in the evening, then cloudy with scattered light showers after midnight. Moderate ridgeline winds in the evening easing overnight.
Sunday Mostly cloudy in the morning with scattered light rain or snow showers, then becoming partly sunny in the afternoon.
Saturday Night Light to occasionally moderate rain and snow showers in the evening, then cloudy with scattered light showers after midnight. Moderate ridgeline winds in the evening easing overnight.
Sunday Mostly cloudy in the morning with scattered light rain or snow showers, then becoming partly sunny in the afternoon.
Saturday Night Light to occasionally moderate rain and snow showers in the evening, then cloudy with scattered light showers after midnight.
Sunday Mostly cloudy in the morning with a chance of light rain or snow showers, then becoming partly to mostly sunny mid-day.
Saturday Night Light to occasionally moderate rain and snow showers in the evening, then cloudy with scattered light showers after midnight. Light to moderate W winds at Pass level and along ridgelines.
Sunday Mostly cloudy in the morning with a chance of light rain or snow showers, then becoming partly to mostly sunny mid-day. Light W winds at Pass level and along ridgelines.
Saturday Night Light to occasionally moderate rain and snow showers in the evening, then cloudy with scattered light showers after midnight. Moderate W winds at Pass level and along ridgelines.
Sunday Mostly cloudy in the morning with a chance of light rain or snow showers, then becoming partly to mostly sunny mid-day. Light W winds at Pass level and along ridgelines.
Saturday Night Light rain and snow showers in the evening, then cloudy with scattered light showers after midnight.
Sunday Mostly cloudy in the morning with a slight chance of light rain or snow showers, then becoming partly to mostly sunny mid-day.
Saturday Night Light rain and snow showers in the evening, then cloudy with scattered light showers after midnight. Periods of moderate ridgeline winds.
Sunday Partly cloudy in the morning becoming mostly sunny mid-day.
Saturday Night Light rain and snow showers in the evening, then cloudy with scattered light showers after midnight. Periods of moderate ridgeline winds.
Sunday Partly cloudy in the morning becoming mostly sunny mid-day.
Saturday Night Light to occasionally moderate rain and snow showers in the evening, then cloudy with scattered light showers after midnight. Periods of moderate ridgeline winds.
Sunday Partly cloudy in the morning becoming mostly sunny mid-day.

Issued: 2:03 PM PST Saturday, December 30, 2023

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

Issued: 2:03 PM PST Saturday, December 30, 2023

Snow Level (ft)

Saturday Evening Saturday Night Sunday Morning Sunday Afternoon Sunday Evening Sunday Night* Monday Morning* Monday Afternoon*
Olympics 4500' 3500' 3500' 4500' 4000' 4000' 4500' 5000'
West North 4500' 3500' 3500' 4500' 3500' 3000' 4000' 4500'
West Central 4500' 3500' 3500' 4500' 3500' 3000' 4000' 4500'
West South 4500' 3500' 3500' 4500' 3500' 3000' 4000' 5000'
Stevens Pass 4500' 3500' 3500' 4500' 3500' 2500' 3000' 3500'
Snoqualmie Pass 4000' 3500' 4000' 4500' 3500' 3000' 3000' 4000'
East North 5000' 3500' 3500' 5000' 2500' 1500' 2000' 3000'
East Central 5000' 4000' 3500' 4500' 3000' 2000' 2500' 3000'
East South 5000' 4000' 4000' 5000' 3000' 2000' 2500' 3500'
Mt. Hood 5000' 4500' 4500' 5000' 5000' 5000' 5500' 6000'
Olympics Elevation
Saturday Evening 4500'
Saturday Night 3500'
Sunday Morning 3500'
Sunday Afternoon 4500'
Sunday Evening 4000'
Sunday Night* 4000'
Monday Morning* 4500'
Monday Afternoon* 5000'
West North Elevation
Saturday Evening 4500'
Saturday Night 3500'
Sunday Morning 3500'
Sunday Afternoon 4500'
Sunday Evening 3500'
Sunday Night* 3000'
Monday Morning* 4000'
Monday Afternoon* 4500'
West Central Elevation
Saturday Evening 4500'
Saturday Night 3500'
Sunday Morning 3500'
Sunday Afternoon 4500'
Sunday Evening 3500'
Sunday Night* 3000'
Monday Morning* 4000'
Monday Afternoon* 4500'
West South Elevation
Saturday Evening 4500'
Saturday Night 3500'
Sunday Morning 3500'
Sunday Afternoon 4500'
Sunday Evening 3500'
Sunday Night* 3000'
Monday Morning* 4000'
Monday Afternoon* 5000'
Stevens Pass Elevation
Saturday Evening 4500'
Saturday Night 3500'
Sunday Morning 3500'
Sunday Afternoon 4500'
Sunday Evening 3500'
Sunday Night* 2500'
Monday Morning* 3000'
Monday Afternoon* 3500'
Snoqualmie Pass Elevation
Saturday Evening 4000'
Saturday Night 3500'
Sunday Morning 4000'
Sunday Afternoon 4500'
Sunday Evening 3500'
Sunday Night* 3000'
Monday Morning* 3000'
Monday Afternoon* 4000'
East North Elevation
Saturday Evening 5000'
Saturday Night 3500'
Sunday Morning 3500'
Sunday Afternoon 5000'
Sunday Evening 2500'
Sunday Night* 1500'
Monday Morning* 2000'
Monday Afternoon* 3000'
East Central Elevation
Saturday Evening 5000'
Saturday Night 4000'
Sunday Morning 3500'
Sunday Afternoon 4500'
Sunday Evening 3000'
Sunday Night* 2000'
Monday Morning* 2500'
Monday Afternoon* 3000'
East South Elevation
Saturday Evening 5000'
Saturday Night 4000'
Sunday Morning 4000'
Sunday Afternoon 5000'
Sunday Evening 3000'
Sunday Night* 2000'
Monday Morning* 2500'
Monday Afternoon* 3500'
Mt. Hood Elevation
Saturday Evening 5000'
Saturday Night 4500'
Sunday Morning 4500'
Sunday Afternoon 5000'
Sunday Evening 5000'
Sunday Night* 5000'
Monday Morning* 5500'
Monday Afternoon* 6000'

Issued: 2:03 PM PST Saturday, December 30, 2023

5000' Temperatures (°F)

Saturday Night Sunday
Max / Min Max / Min
Olympics 31 / 27 30 / 27
West North 33 / 27 30 / 27
West Central 32 / 27 30 / 27
West South 32 / 27 30 / 27
Stevens Pass 32 / 28 30 / 27
Snoqualmie Pass 32 / 27 29 / 27
East North 32 / 26 29 / 26
East Central 32 / 27 30 / 27
East South 32 / 27 32 / 27
Mt. Hood 33 / 30 33 / 30
Olympics 5000' Temperature Forecast
(Max / Min)
Saturday Night 31 / 27
Sunday 30 / 27
West North 5000' Temperature Forecast
(Max / Min)
Saturday Night 33 / 27
Sunday 30 / 27
West Central 5000' Temperature Forecast
(Max / Min)
Saturday Night 32 / 27
Sunday 30 / 27
West South 5000' Temperature Forecast
(Max / Min)
Saturday Night 32 / 27
Sunday 30 / 27
Stevens Pass 5000' Temperature Forecast
(Max / Min)
Saturday Night 32 / 28
Sunday 30 / 27
Snoqualmie Pass 5000' Temperature Forecast
(Max / Min)
Saturday Night 32 / 27
Sunday 29 / 27
East North 5000' Temperature Forecast
(Max / Min)
Saturday Night 32 / 26
Sunday 29 / 26
East Central 5000' Temperature Forecast
(Max / Min)
Saturday Night 32 / 27
Sunday 30 / 27
East South 5000' Temperature Forecast
(Max / Min)
Saturday Night 32 / 27
Sunday 32 / 27
Mt. Hood 5000' Temperature Forecast
(Max / Min)
Saturday Night 33 / 30
Sunday 33 / 30

Issued: 2:03 PM PST Saturday, December 30, 2023

Ridgeline Winds (mph)

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

Issued: 2:03 PM PST Saturday, December 30, 2023

Extended Weather Synopsis

A familiar pattern will ensue with a splitting and weak weather system approaching the area Monday night through Wednesday.  This will likely bring increased cloud cover, cool E-SE winds to the Cascades, with the best chance of light rain or high elevation snow for the Olymipcs. The longer range forecast hints at a cooler storm or storms toward the end of next week...stay tuned! 

Extended Snow Level (ft)

Monday Night* Tuesday * Tuesday Night* Wednesday *
West North 5000' 5500' 4500' 5000'
Snoqualmie Pass 3000' 3000' 3000' 4500'
Mt. Hood 6000' 5500' 3500' 4000'
West North Elevation
Monday Night* 5000'
Tuesday * 5500'
Tuesday Night* 4500'
Wednesday * 5000'
Snoqualmie Pass Elevation
Monday Night* 3000'
Tuesday * 3000'
Tuesday Night* 3000'
Wednesday * 4500'
Mt. Hood Elevation
Monday Night* 6000'
Tuesday * 5500'
Tuesday Night* 3500'
Wednesday * 4000'

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

Previous forecast from Dec 30, 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’.