Issued: 2:02 PM PST Saturday, December 23, 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

Saturday hit all the right notes with mostly sunny skies, generally light winds, and mountain temperatures rising into the 20s and 30s in the afternoon. The ridge of high pressure currently over the area will slide east tonight opening the door to increasing high and eventually mid-level clouds to spread over the region. A weak weather system will pass through the area on Sunday with periods of light snowfall in the afternoon. The bigger story will be the wind Saturday night into Sunday. Offshore flow will crank up as the front approaches with moderate to locally strong S through SE winds through Sunday. There may be a few leftover light showers as the trough exits stage right Sunday night.

There's an interesting, impactful forecast shaping up for Christmas Day and night.  Warm frontal precipitation from a strong frontal system will move onshore Monday. The bulk of this atmospheric river will directed into southern British Columbia as upper level ridging shunts the moisture tap north. The northwest Cascades and Olympics will likely see increasing precipitation rates, winds, and rising snow levels during the day. Other areas will see precipitation and winds increase on Monday as well, albeit relatively lighter. Cool easterly flow cranks up another notch with this system and should help keep a warm-up at bay during the daylight hours. However, whenever we have milder air trying to overrun sub-freezing air, we have a recipe for freezing rain. There's a range of outcomes, but the best guess at this point is the Cascade trailheads and Passes see snow on Monday, but the western approaches to the Cascade Passes and foothills (Hwy2, I-90,US12) and near the Columbia R. Gorge run a higher risk of freezing rain.  

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 clear in the evening, then becoming cloudy with increasing high clouds after midnight.
Sunday Cloudy with periods of light rain and snow beginning late morning. Moderate ridgeline winds.
Saturday Night Mostly clear in the evening, then becoming mostly cloudy with increasing high clouds after midnight.
Sunday Cloudy with periods of light rain and snow beginning late morning. Moderate ridgeline winds in the morning, potentially becoming strong in the afternoon.
Saturday Night Mostly clear in the evening, then becoming mostly cloudy with increasing high clouds after midnight.
Sunday Cloudy with periods of light rain and snow beginning around mid-day. Moderate ridgeline winds.
Saturday Night Mostly clear in the evening, then becoming mostly cloudy with increasing high clouds after midnight. Areas of low clouds likely developing near White Pass. Moderate to strong ridgeline winds developing overnight.
Sunday Cloudy with periods of light rain and snow beginning around mid-day. Moderate to strong ridgeline winds.
Saturday Night Mostly clear in the evening, then becoming mostly cloudy with increasing high clouds after midnight. Areas of low clouds likely developing. Moderate E-SE winds at Pass level and ridgelines developing overnight.
Sunday Cloudy with periods of light rain and snow beginning around mid-day. Moderate E-SE Pass level and ridgeline winds.
Saturday Night Mostly clear in the evening, then becoming mostly cloudy with increasing high clouds after midnight. Areas of low clouds likely developing. Moderate to strong E-SE winds at Pass level and ridgelines developing overnight.
Sunday Cloudy with periods of light rain and snow beginning around mid-day. Moderate to strong E-SE Pass level and ridgeline winds.
Saturday Night Mostly clear in the evening, then becoming mostly cloudy with increasing high clouds after midnight.
Sunday Cloudy with periods of light rain and snow beginning after mid-day. Moderate ridgeline winds.
Saturday Night Mostly clear in the evening, then becoming mostly cloudy with increasing high clouds after midnight. Moderate ridgeline winds developing overnight.
Sunday Cloudy with periods of light rain and snow beginning after mid-day. Moderate ridgeline winds.
Saturday Night Mostly clear in the evening, then becoming mostly cloudy with increasing high clouds after midnight. Moderate ridgeline winds developing overnight.
Sunday Cloudy with periods of light rain and snow beginning after mid-day. Moderate ridgeline winds.
Saturday Night Mostly clear in the evening, then becoming mostly cloudy with increasing high clouds after midnight. Moderate ridgeline winds developing overnight.
Sunday Cloudy with periods of light rain and snow beginning around mid-day. Moderate ridgeline winds becoming strong in the afternoon.

Issued: 2:02 PM PST Saturday, December 23, 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 0 LT 0.10 LT 0.10 0.25 - 0.50
Mt Baker Ski Area 0 LT 0.10 LT 0.10 0.75
Mt. Loop - Barlow Pass 0 LT 0.10 LT 0.10 0.25 - 0.50
Stevens Pass 0 LT 0.10 LT 0.10 0.25
Snoqualmie Pass 0 LT 0.10 LT 0.10 0.25
Crystal Mt 0 LT 0.10 LT 0.10 0.25
Paradise 0 LT 0.10 LT 0.10 0.25 - 0.50
White Pass 0 LT 0.10 LT 0.10 LT 0.25
Washington Pass 0 LT 0.10 LT 0.10 LT 0.25
Mission Ridge 0 0 0 LT 0.10
Salmon la Sac - Gallagher Head 0 LT 0.10 0 LT 0.25
Tieton River - Darland Mt. 0 LT 0.10 LT 0.10 LT 0.25
Mt Hood Meadows 0 LT 0.10 LT 0.10 0.25
Timberline 0 LT 0.10 LT 0.10 0.25
Hurricane Ridge Precipitation (in)
Saturday Night 0
Sunday LT 0.10
Sunday Night LT 0.10
Monday 0.25 - 0.50
Mt Baker Ski Area Precipitation (in)
Saturday Night 0
Sunday LT 0.10
Sunday Night LT 0.10
Monday 0.75
Mt. Loop - Barlow Pass Precipitation (in)
Saturday Night 0
Sunday LT 0.10
Sunday Night LT 0.10
Monday 0.25 - 0.50
Stevens Pass Precipitation (in)
Saturday Night 0
Sunday LT 0.10
Sunday Night LT 0.10
Monday 0.25
Snoqualmie Pass Precipitation (in)
Saturday Night 0
Sunday LT 0.10
Sunday Night LT 0.10
Monday 0.25
Crystal Mt Precipitation (in)
Saturday Night 0
Sunday LT 0.10
Sunday Night LT 0.10
Monday 0.25
Paradise Precipitation (in)
Saturday Night 0
Sunday LT 0.10
Sunday Night LT 0.10
Monday 0.25 - 0.50
White Pass Precipitation (in)
Saturday Night 0
Sunday LT 0.10
Sunday Night LT 0.10
Monday LT 0.25
Washington Pass Precipitation (in)
Saturday Night 0
Sunday LT 0.10
Sunday Night LT 0.10
Monday LT 0.25
Mission Ridge Precipitation (in)
Saturday Night 0
Sunday 0
Sunday Night 0
Monday LT 0.10
Salmon la Sac - Gallagher Head Precipitation (in)
Saturday Night 0
Sunday LT 0.10
Sunday Night 0
Monday LT 0.25
Tieton River - Darland Mt. Precipitation (in)
Saturday Night 0
Sunday LT 0.10
Sunday Night LT 0.10
Monday LT 0.25
Mt Hood Meadows Precipitation (in)
Saturday Night 0
Sunday LT 0.10
Sunday Night LT 0.10
Monday 0.25
Timberline Precipitation (in)
Saturday Night 0
Sunday LT 0.10
Sunday Night LT 0.10
Monday 0.25

Issued: 2:02 PM PST Saturday, December 23, 2023

Snow Level (ft)

Saturday Evening* Saturday Night* Sunday Morning* Sunday Afternoon* Sunday Evening* Sunday Night* Monday Morning* Monday Afternoon*
Olympics 3500' 6000' 5000' 3500' 3500' 4000' 5500' 7000'
West North 2000' 3500' 3000' 2000' 2000' 2000' 3500' 4500'
West Central 2500' 1500' 1500' 2500' 2000' 1500' 2500' 3500'
West South 2500' 1500' 1500' 3000' 2000' 1500' 1500' 3000'
Stevens Pass 2000' 1000' 1000' 1500' 1500' 1000' 1000' 1500'
Snoqualmie Pass 2000' 1000' 1000' 2000' 2000' 1500' 1500' 2000'
East North 2000' 1000' 1000' 1500' 1000' 0 0 1000'
East Central 2000' 1000' 1000' 1500' 1000' 1000' 1000' 1000'
East South 2000' 1000' 1000' 1500' 1000' 1000' 1000' 1500'
Mt. Hood 2500' 2500' 3000' 3500' 3000' 3000' 3000' 7000'
Olympics Elevation
Saturday Evening* 3500'
Saturday Night* 6000'
Sunday Morning* 5000'
Sunday Afternoon* 3500'
Sunday Evening* 3500'
Sunday Night* 4000'
Monday Morning* 5500'
Monday Afternoon* 7000'
West North Elevation
Saturday Evening* 2000'
Saturday Night* 3500'
Sunday Morning* 3000'
Sunday Afternoon* 2000'
Sunday Evening* 2000'
Sunday Night* 2000'
Monday Morning* 3500'
Monday Afternoon* 4500'
West Central Elevation
Saturday Evening* 2500'
Saturday Night* 1500'
Sunday Morning* 1500'
Sunday Afternoon* 2500'
Sunday Evening* 2000'
Sunday Night* 1500'
Monday Morning* 2500'
Monday Afternoon* 3500'
West South Elevation
Saturday Evening* 2500'
Saturday Night* 1500'
Sunday Morning* 1500'
Sunday Afternoon* 3000'
Sunday Evening* 2000'
Sunday Night* 1500'
Monday Morning* 1500'
Monday Afternoon* 3000'
Stevens Pass Elevation
Saturday Evening* 2000'
Saturday Night* 1000'
Sunday Morning* 1000'
Sunday Afternoon* 1500'
Sunday Evening* 1500'
Sunday Night* 1000'
Monday Morning* 1000'
Monday Afternoon* 1500'
Snoqualmie Pass Elevation
Saturday Evening* 2000'
Saturday Night* 1000'
Sunday Morning* 1000'
Sunday Afternoon* 2000'
Sunday Evening* 2000'
Sunday Night* 1500'
Monday Morning* 1500'
Monday Afternoon* 2000'
East North Elevation
Saturday Evening* 2000'
Saturday Night* 1000'
Sunday Morning* 1000'
Sunday Afternoon* 1500'
Sunday Evening* 1000'
Sunday Night* 0'
Monday Morning* 0'
Monday Afternoon* 1000'
East Central Elevation
Saturday Evening* 2000'
Saturday Night* 1000'
Sunday Morning* 1000'
Sunday Afternoon* 1500'
Sunday Evening* 1000'
Sunday Night* 1000'
Monday Morning* 1000'
Monday Afternoon* 1000'
East South Elevation
Saturday Evening* 2000'
Saturday Night* 1000'
Sunday Morning* 1000'
Sunday Afternoon* 1500'
Sunday Evening* 1000'
Sunday Night* 1000'
Monday Morning* 1000'
Monday Afternoon* 1500'
Mt. Hood Elevation
Saturday Evening* 2500'
Saturday Night* 2500'
Sunday Morning* 3000'
Sunday Afternoon* 3500'
Sunday Evening* 3000'
Sunday Night* 3000'
Monday Morning* 3000'
Monday Afternoon* 7000'

Issued: 2:02 PM PST Saturday, December 23, 2023

5000' Temperatures (°F)

Saturday Night Sunday
Max / Min Max / Min
Olympics 33 / 27 31 / 25
West North 28 / 24 30 / 25
West Central 26 / 23 28 / 24
West South 25 / 20 31 / 25
Stevens Pass 22 / 19 26 / 20
Snoqualmie Pass 25 / 20 26 / 21
East North 20 / 13 22 / 14
East Central 19 / 15 25 / 17
East South 19 / 16 28 / 18
Mt. Hood 26 / 22 33 / 27
Olympics 5000' Temperature Forecast
(Max / Min)
Saturday Night 33 / 27
Sunday 31 / 25
West North 5000' Temperature Forecast
(Max / Min)
Saturday Night 28 / 24
Sunday 30 / 25
West Central 5000' Temperature Forecast
(Max / Min)
Saturday Night 26 / 23
Sunday 28 / 24
West South 5000' Temperature Forecast
(Max / Min)
Saturday Night 25 / 20
Sunday 31 / 25
Stevens Pass 5000' Temperature Forecast
(Max / Min)
Saturday Night 22 / 19
Sunday 26 / 20
Snoqualmie Pass 5000' Temperature Forecast
(Max / Min)
Saturday Night 25 / 20
Sunday 26 / 21
East North 5000' Temperature Forecast
(Max / Min)
Saturday Night 20 / 13
Sunday 22 / 14
East Central 5000' Temperature Forecast
(Max / Min)
Saturday Night 19 / 15
Sunday 25 / 17
East South 5000' Temperature Forecast
(Max / Min)
Saturday Night 19 / 16
Sunday 28 / 18
Mt. Hood 5000' Temperature Forecast
(Max / Min)
Saturday Night 26 / 22
Sunday 33 / 27

Issued: 2:02 PM PST Saturday, December 23, 2023

Ridgeline Winds (mph)

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

Issued: 2:02 PM PST Saturday, December 23, 2023

Extended Weather Synopsis

Monday night be may the peak of the storm for precipitation rates and warming.  Heavy precipitation is likely overnight for the Olympics and northwest Cascades with more moderate precipitation totals further south and east. This could expand the wintry mix area eastward and into the Cascade Passes as well as move the rain/snow line up the hill for areas west of the Cascade crest.  A frontal boundary will likely sweep through early Tuesday morning with precipitation winding down.  

A strong ridge of high pressure anchored over the inland NW will play a major role over the rest of the week. A frontal system on Wednesday will likely weaken and split as it approaches are coast. The result will probably be a lighter round of precipitation vs Monday/Monday night, but the chances for a wintry mix near the Cascade Passes will continue in this pattern. 

Extended Snow Level (ft)

Monday Night* Tuesday * Tuesday Night* Wednesday *
West North 5000' 4000' 3500' 4000'
Snoqualmie Pass 2500' 4500' 3000' 4000'
Mt. Hood 6000' 6500' 5000' 6500'
West North Elevation
Monday Night* 5000'
Tuesday * 4000'
Tuesday Night* 3500'
Wednesday * 4000'
Snoqualmie Pass Elevation
Monday Night* 2500'
Tuesday * 4500'
Tuesday Night* 3000'
Wednesday * 4000'
Mt. Hood Elevation
Monday Night* 6000'
Tuesday * 6500'
Tuesday Night* 5000'
Wednesday * 6500'

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

Previous forecast from Dec 23, 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’.