Issued: 7:39 PM PST Saturday, December 2, 2023
by Dallas Glass

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

Weather Synopsis

Following a cold and snowy period, the active weather patterns turns up the moisture dial and the temperatures as well: we're bracing for two atmospheric river events.

Saturday evening light snow showers continue to taper in post-frontal westerly flow as slightly cooler air settles in.

An approaching warm front begins to lift northward in the early morning hours. Warming and steady precipitation start first at Mt Hood with increasing rain and snow as snow levels rise. By morning, expect snow levels there to be above 7000 ft. While the heaviest precipitation will focus on Mt Hood on Sunday (where 24-hour precipitation totals could be in the 3-3.5" range), the southern Washington Cascades will also receive 1-2" of precipitation as snow changes to rain at most low and mid elevations from south to north as the day progresses. This transition will be particularly messy at the Cascade Passes where low-level E flow in the morning could create freezing rain or sleet in the mid-morning hours as the warm air over-runs it. By late in the day, W winds will overwhelm the cold air pool in most areas, except perhaps Washington Pass where there is a 50/50 chance precipitation stays all snow.

A cold front pushing through Sunday afternoon brings slightly cooler conditions, with light rain and snow showers along the west slopes of the Cascades Sunday night.

The second atmospheric river approaches on Monday with more rain and further increases in snow levels along with E winds. This time, the cold pool east of the Cascades will be very week and not particularly relevant.

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 snow showers in the evening. Light snow developing overnight. Light to occasionally moderate ridgeline winds.
Sunday Light to moderate rain and snow in the morning. Rising snow levels. Moderate ridgeline winds.
Saturday Night Decreasing light snow showers tapering to flurries after midnight. Light ridgeline winds.
Sunday Increasing rain snow along with rising snow levels in the morning, then becoming light rain and snow showers late in the day. Increasing moderate winds.
Saturday Night Decreasing light to moderate snow showers tapering to flurries after midnight. Light to moderate ridgeline winds becoming light overnight.
Sunday Increasing moderate to heavy rain and snow along with rising snow levels, then moderate rain and snow showers in the afternoon. Light to moderate ridgeline winds.
Saturday Night Light showers in the evening with light snow developing in the early morning hours. Light to moderate ridgeline winds become light.
Sunday Heavy rain and snow along with rising snow levels with moderate rain and snow showers in the afternoon. Moderate ridgeline winds.
Saturday Night Decreasing light to moderate snow showers tapering to flurries after midnight. Moderate ridgeline winds become light. Light W wind at the Pass switches E in the early morning hours.
Sunday Moderate to heavy to start with a wintry mix likely late morning, then a changeover to rain. Ridgeline winds increase into the moderate range by the afternoon. Mostly light E winds switch W at the Pass by the afternoon.
Saturday Night Decreasing light to moderate snow showers tapering to flurries after midnight. Moderate ridgeline winds become light. Light to moderate W wind in the early evening becomes light overnight at the Pass switches E in the early morning hours.
Sunday Heavy snow to start with a wintry mix likely mid-morning, then a changeover to rain. Ridgeline winds increase into the moderate range by mid-morning. Mostly light E winds switch W at the Pass by the afternoon.
Saturday Night Light snow showers decrease or end. Moderate ridgeline winds becoming light.
Sunday Increasing light to moderate snow, possibly mixing with rain right at the end of the day. Ridgeline winds increasing into the moderate range.
Saturday Night Light snow showers decrease or end. Moderate ridgeline winds becoming light.
Sunday Moderate snow, mixing with and then changing to rain. Increasing moderate ridgeline winds.
Saturday Night Snow flurries in the evening, then light snow develops in the early morning hours. Decreasing light to moderate ridgeline winds.
Sunday Increasing light to moderate snow changing to rain at lower and middle elevations by the afternoon. Ridgeline winds increasing into the moderate range.
Saturday Night Light snow becoming moderate to heavy overnight. Moderate to strong ridgeline winds.
Sunday Very heavy rain and high-elevation snow. Strong ridgeline winds.

Issued: 7:39 PM PST Saturday, December 2, 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 0.25 LT 0.10 0.50
Mt Baker Ski Area LT 0.10 0.50 LT 0.10 0.75
Mt. Loop - Barlow Pass LT 0.25 1.00 LT 0.10 1.00
Stevens Pass LT 0.25 1.00 LT 0.10 0.75
Snoqualmie Pass LT 0.25 1.50 LT 0.10 1.00
Crystal Mt LT 0.10 0.50 LT 0.10 0.50
Paradise 0.25 2.00 LT 0.25 1.50
White Pass LT 0.25 1.00 LT 0.25 0.50
Washington Pass LT 0.10 0.50 - 0.75 LT 0.10 0.25 - 0.50
Mission Ridge 0 0.25 - 0.50 0 0.25 - 0.50
Salmon la Sac - Gallagher Head LT 0.10 0.75 -1.00 LT 0.10 0.50 - 0.75
Tieton River - Darland Mt. LT 0.10 0.50 LT 0.10 0.50
Mt Hood Meadows 0.75 -1.00 2.50 - 3.50 0.25 - 0.50 0.75
Timberline 1.00 3.00 - 4.00 0.50 0.75
Hurricane Ridge Precipitation (in)
Saturday Night LT 0.10
Sunday 0.25
Sunday Night LT 0.10
Monday 0.50
Mt Baker Ski Area Precipitation (in)
Saturday Night LT 0.10
Sunday 0.50
Sunday Night LT 0.10
Monday 0.75
Mt. Loop - Barlow Pass Precipitation (in)
Saturday Night LT 0.25
Sunday 1.00
Sunday Night LT 0.10
Monday 1.00
Stevens Pass Precipitation (in)
Saturday Night LT 0.25
Sunday 1.00
Sunday Night LT 0.10
Monday 0.75
Snoqualmie Pass Precipitation (in)
Saturday Night LT 0.25
Sunday 1.50
Sunday Night LT 0.10
Monday 1.00
Crystal Mt Precipitation (in)
Saturday Night LT 0.10
Sunday 0.50
Sunday Night LT 0.10
Monday 0.50
Paradise Precipitation (in)
Saturday Night 0.25
Sunday 2.00
Sunday Night LT 0.25
Monday 1.50
White Pass Precipitation (in)
Saturday Night LT 0.25
Sunday 1.00
Sunday Night LT 0.25
Monday 0.50
Washington Pass Precipitation (in)
Saturday Night LT 0.10
Sunday 0.50 - 0.75
Sunday Night LT 0.10
Monday 0.25 - 0.50
Mission Ridge Precipitation (in)
Saturday Night 0
Sunday 0.25 - 0.50
Sunday Night 0
Monday 0.25 - 0.50
Salmon la Sac - Gallagher Head Precipitation (in)
Saturday Night LT 0.10
Sunday 0.75 -1.00
Sunday Night LT 0.10
Monday 0.50 - 0.75
Tieton River - Darland Mt. Precipitation (in)
Saturday Night LT 0.10
Sunday 0.50
Sunday Night LT 0.10
Monday 0.50
Mt Hood Meadows Precipitation (in)
Saturday Night 0.75 -1.00
Sunday 2.50 - 3.50
Sunday Night 0.25 - 0.50
Monday 0.75
Timberline Precipitation (in)
Saturday Night 1.00
Sunday 3.00 - 4.00
Sunday Night 0.50
Monday 0.75

Issued: 7:39 PM PST Saturday, December 2, 2023

Snow Level (ft)

Saturday Evening Saturday Night* Sunday Morning* Sunday Afternoon* Sunday Evening Sunday Night Monday Morning* Monday Afternoon*
Olympics 3000' 2500' 5000' 6500' 4000' 4000' 6000' 8500'
West North 2500' 2000' 2500' 4000' 3500' 3000' 3500' 6000'
West Central 2500' 2500' 2500' 5500' 4000' 3000' 3500' 6500'
West South 3000' 2500' 4500' 7000' 5500' 3500' 4000' 8000'
Stevens Pass 2500' 2000' 2000' 4500' 4500' 3000' 3000' 5500'
Snoqualmie Pass 3000' 2500' 3000' 5500' 4500' 3000' 3000' 7000'
East North 2000' 1000' 1000' 3500' 3500' 2000' 2500' 4500'
East Central 2500' 1500' 2500' 5000' 5000' 3000' 3000' 5500'
East South 3000' 2500' 4000' 6000' 6000' 4000' 5000' 8000'
Mt. Hood 3500' 4500' 7000' 6000' 6000' 7000' 8000' 9000'
Olympics Elevation
Saturday Evening 3000'
Saturday Night* 2500'
Sunday Morning* 5000'
Sunday Afternoon* 6500'
Sunday Evening 4000'
Sunday Night 4000'
Monday Morning* 6000'
Monday Afternoon* 8500'
West North Elevation
Saturday Evening 2500'
Saturday Night* 2000'
Sunday Morning* 2500'
Sunday Afternoon* 4000'
Sunday Evening 3500'
Sunday Night 3000'
Monday Morning* 3500'
Monday Afternoon* 6000'
West Central Elevation
Saturday Evening 2500'
Saturday Night* 2500'
Sunday Morning* 2500'
Sunday Afternoon* 5500'
Sunday Evening 4000'
Sunday Night 3000'
Monday Morning* 3500'
Monday Afternoon* 6500'
West South Elevation
Saturday Evening 3000'
Saturday Night* 2500'
Sunday Morning* 4500'
Sunday Afternoon* 7000'
Sunday Evening 5500'
Sunday Night 3500'
Monday Morning* 4000'
Monday Afternoon* 8000'
Stevens Pass Elevation
Saturday Evening 2500'
Saturday Night* 2000'
Sunday Morning* 2000'
Sunday Afternoon* 4500'
Sunday Evening 4500'
Sunday Night 3000'
Monday Morning* 3000'
Monday Afternoon* 5500'
Snoqualmie Pass Elevation
Saturday Evening 3000'
Saturday Night* 2500'
Sunday Morning* 3000'
Sunday Afternoon* 5500'
Sunday Evening 4500'
Sunday Night 3000'
Monday Morning* 3000'
Monday Afternoon* 7000'
East North Elevation
Saturday Evening 2000'
Saturday Night* 1000'
Sunday Morning* 1000'
Sunday Afternoon* 3500'
Sunday Evening 3500'
Sunday Night 2000'
Monday Morning* 2500'
Monday Afternoon* 4500'
East Central Elevation
Saturday Evening 2500'
Saturday Night* 1500'
Sunday Morning* 2500'
Sunday Afternoon* 5000'
Sunday Evening 5000'
Sunday Night 3000'
Monday Morning* 3000'
Monday Afternoon* 5500'
East South Elevation
Saturday Evening 3000'
Saturday Night* 2500'
Sunday Morning* 4000'
Sunday Afternoon* 6000'
Sunday Evening 6000'
Sunday Night 4000'
Monday Morning* 5000'
Monday Afternoon* 8000'
Mt. Hood Elevation
Saturday Evening 3500'
Saturday Night* 4500'
Sunday Morning* 7000'
Sunday Afternoon* 6000'
Sunday Evening 6000'
Sunday Night 7000'
Monday Morning* 8000'
Monday Afternoon* 9000'

Issued: 7:39 PM PST Saturday, December 2, 2023

5000' Temperatures (°F)

Saturday Night Sunday
Max / Min Max / Min
Olympics 33 / 26 38 / 29
West North 25 / 24 35 / 28
West Central 28 / 26 38 / 29
West South 30 / 24 39 / 30
Stevens Pass 26 / 23 38 / 26
Snoqualmie Pass 27 / 23 38 / 27
East North 21 / 18 33 / 21
East Central 27 / 22 38 / 27
East South 29 / 24 39 / 29
Mt. Hood 35 / 29 38 / 29
Olympics 5000' Temperature Forecast
(Max / Min)
Saturday Night 33 / 26
Sunday 38 / 29
West North 5000' Temperature Forecast
(Max / Min)
Saturday Night 25 / 24
Sunday 35 / 28
West Central 5000' Temperature Forecast
(Max / Min)
Saturday Night 28 / 26
Sunday 38 / 29
West South 5000' Temperature Forecast
(Max / Min)
Saturday Night 30 / 24
Sunday 39 / 30
Stevens Pass 5000' Temperature Forecast
(Max / Min)
Saturday Night 26 / 23
Sunday 38 / 26
Snoqualmie Pass 5000' Temperature Forecast
(Max / Min)
Saturday Night 27 / 23
Sunday 38 / 27
East North 5000' Temperature Forecast
(Max / Min)
Saturday Night 21 / 18
Sunday 33 / 21
East Central 5000' Temperature Forecast
(Max / Min)
Saturday Night 27 / 22
Sunday 38 / 27
East South 5000' Temperature Forecast
(Max / Min)
Saturday Night 29 / 24
Sunday 39 / 29
Mt. Hood 5000' Temperature Forecast
(Max / Min)
Saturday Night 35 / 29
Sunday 38 / 29

Issued: 7:39 PM PST Saturday, December 2, 2023

Ridgeline Winds (mph)

Saturday Evening Saturday Night Sunday Morning Sunday Afternoon
Olympics SW 10-20 SSW 5-15 SW 15-25 WSW 15-25
West North W 10-20 SSW 5-15 SSW 15-25 SW 20-30
West Central W 10-20 SSW 5-15 SSE 10-20 WSW 15-25
West South WSW 10-20 SSW 5-15 SW 5-15 WSW 15-25
Stevens Pass W 15-25 SW 5-15 S 5-15 WSW 15-25
Snoqualmie Pass W 20-30 SSW 5-15 SE 5-15 WSW 20-30
East North W 10-20 SW 5-15 S 5-15 WSW 20-30
East Central W 20-30 WSW 10-20 SW 10-20 WSW 25-35
East South W 10-20 WSW 5-15 SW 10-20 WSW 15-25
Mt. Hood WSW 25-35 WSW 20-30 WSW 25-35 WSW 30-40
Olympics Ridgeline Winds (mph)
Saturday Evening SW 10-20
Saturday Night SSW 5-15
Sunday Morning SW 15-25
Sunday Afternoon WSW 15-25
West North Ridgeline Winds (mph)
Saturday Evening W 10-20
Saturday Night SSW 5-15
Sunday Morning SSW 15-25
Sunday Afternoon SW 20-30
West Central Ridgeline Winds (mph)
Saturday Evening W 10-20
Saturday Night SSW 5-15
Sunday Morning SSE 10-20
Sunday Afternoon WSW 15-25
West South Ridgeline Winds (mph)
Saturday Evening WSW 10-20
Saturday Night SSW 5-15
Sunday Morning SW 5-15
Sunday Afternoon WSW 15-25
Stevens Pass Ridgeline Winds (mph)
Saturday Evening W 15-25
Saturday Night SW 5-15
Sunday Morning S 5-15
Sunday Afternoon WSW 15-25
Snoqualmie Pass Ridgeline Winds (mph)
Saturday Evening W 20-30
Saturday Night SSW 5-15
Sunday Morning SE 5-15
Sunday Afternoon WSW 20-30
East North Ridgeline Winds (mph)
Saturday Evening W 10-20
Saturday Night SW 5-15
Sunday Morning S 5-15
Sunday Afternoon WSW 20-30
East Central Ridgeline Winds (mph)
Saturday Evening W 20-30
Saturday Night WSW 10-20
Sunday Morning SW 10-20
Sunday Afternoon WSW 25-35
East South Ridgeline Winds (mph)
Saturday Evening W 10-20
Saturday Night WSW 5-15
Sunday Morning SW 10-20
Sunday Afternoon WSW 15-25
Mt. Hood Ridgeline Winds (mph)
Saturday Evening WSW 25-35
Saturday Night WSW 20-30
Sunday Morning WSW 25-35
Sunday Afternoon WSW 30-40

Issued: 7:39 PM PST Saturday, December 2, 2023

Extended Weather Synopsis

The majority of the second atmospheric river arrives Monday night warm front pushing snow levels up to around 9000 ft. The heaviest precipitation arrives late Monday night and early Tuesday before a cold front eases southward Tuesday afternoon. The cold front and associated moisture linger on Tuesday night over Mt Hood with cooling temperatures bringing chances for snowfall once again by Wednesday.

Extended Snow Level (ft)

Monday Night* Tuesday Tuesday Night Wednesday
West North 8500' 6000' 4000' 3500'
Snoqualmie Pass 9000' 7500' 5500' 4000'
Mt. Hood 9500' 9000' 8000' 6000'
West North Elevation
Monday Night* 8500'
Tuesday 6000'
Tuesday Night 4000'
Wednesday 3500'
Snoqualmie Pass Elevation
Monday Night* 9000'
Tuesday 7500'
Tuesday Night 5500'
Wednesday 4000'
Mt. Hood Elevation
Monday Night* 9500'
Tuesday 9000'
Tuesday Night 8000'
Wednesday 6000'

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

Previous forecast from Dec 2, 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’.