Issued: 2:09 PM PST Monday, December 4, 2023
by Matt Primomo

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

Weather Synopsis

The brunt of an impressive plume of warm, moisture laden air arrives tonight. The SW-NE oriented firehose blasts over the mountains and stays with us for a while. The heaviest precipitation, strongest winds, and warmest temperatures should occur overnight and during the first half of the day on Tuesday. We could see sustained ridgetop winds of 40-55mph in exposed locations, with rainfall rates that easily exceed 0.25"/hr in favored locations. Needless to say, the west side of the North and Central Cascades stand to squeeze out moisture that could amount to 5-9" of water in the 36hr period ending Tuesday afternoon. The east side of the Central and South Cascades may get relatively spared from the drenching as the storm stalls out NW of that area.

By early morning, snow levels should have peaked for most locations, reaching the 7,500-10,000ft range before slowly dropping down. The northern third of the region may start to see wet snowfall by late in the day on Tuesday. Wind speeds should be on a gradual decline during the day, but remain elevated for the southern third of the region.

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
Monday Night Very heavy rain with moderate to strong ridgetop winds.
Tuesday Moderate rain, tapering and cooling slightly.
Monday Night Very heavy rain with moderate to strong ridgetop winds.
Tuesday Very heavy rain early, then becoming heavy and tapering slightly
Monday Night Very heavy rain with moderate to strong ridgetop winds.
Tuesday Very heavy rain early, then becoming heavy and tapering slightly
Monday Night Moderate rain showers, could be heavy in favored locations.
Tuesday Moderate to heavy rain showers.
Monday Night Heavy rain with moderate to strong ridgetop winds.
Tuesday Heavy rain early, then becoming moderate and tapering slightly.
Monday Night Heavy rain with moderate to strong ridgetop winds.
Tuesday Heavy rain early, then becoming moderate and tapering slightly
Monday Night Heavy snow and rain with moderate to strong ridgetop winds.
Tuesday Heavy rain and high elevation snow, then becoming moderate and tapering slightly.
Monday Night Heavy rain with strong ridgetop winds.
Tuesday Moderate rain.
Monday Night Light to moderate rain showers.
Tuesday Moderate rain showers.
Monday Night Light to moderate rain.
Tuesday Moderate rain showers, increasing and becoming heavier later.

Issued: 2:09 PM PST Monday, December 4, 2023

Precipitation (in)

Monday Night Tuesday Tuesday Night Wednesday
4 pm - 4 am 4 am - 4 pm 4 pm - 4 am 4 am - 4 pm
Hurricane Ridge 1.50 - 2.00 0.25 - 0.50 LT 0.25 0.25 - 0.50
Mt Baker Ski Area 2.50 - 3.50 1.00 0.25 0.25 - 0.50
Mt. Loop - Barlow Pass 2.50 - 3.50 1.50 - 2.00 0.25 - 0.50 0.25 - 0.50
Stevens Pass 1.00 - 1.50 0.75 0.25 - 0.50 0.25
Snoqualmie Pass 1.50 1.00 0.50 0.25
Crystal Mt 1.00 0.50 - 0.75 0.75 0.50
Paradise 2.50 1.50 - 2.00 1.00 1.00 - 1.50
White Pass 0.75 0.75 -1.00 0.50 0.25 - 0.50
Washington Pass 1.50 - 2.00 1.00 LT 0.25 LT 0.25
Mission Ridge 0.25 LT 0.25 0.50 0.25
Salmon la Sac - Gallagher Head 0.75 1.00 0.50 0.25
Tieton River - Darland Mt. 0.50 0.50 0.25 - 0.50 0.25
Mt Hood Meadows 0.25 1.50 1.00 1.00
Timberline 0.25 1.00 - 1.50 1.00 1.00
Hurricane Ridge Precipitation (in)
Monday Night 1.50 - 2.00
Tuesday 0.25 - 0.50
Tuesday Night LT 0.25
Wednesday 0.25 - 0.50
Mt Baker Ski Area Precipitation (in)
Monday Night 2.50 - 3.50
Tuesday 1.00
Tuesday Night 0.25
Wednesday 0.25 - 0.50
Mt. Loop - Barlow Pass Precipitation (in)
Monday Night 2.50 - 3.50
Tuesday 1.50 - 2.00
Tuesday Night 0.25 - 0.50
Wednesday 0.25 - 0.50
Stevens Pass Precipitation (in)
Monday Night 1.00 - 1.50
Tuesday 0.75
Tuesday Night 0.25 - 0.50
Wednesday 0.25
Snoqualmie Pass Precipitation (in)
Monday Night 1.50
Tuesday 1.00
Tuesday Night 0.50
Wednesday 0.25
Crystal Mt Precipitation (in)
Monday Night 1.00
Tuesday 0.50 - 0.75
Tuesday Night 0.75
Wednesday 0.50
Paradise Precipitation (in)
Monday Night 2.50
Tuesday 1.50 - 2.00
Tuesday Night 1.00
Wednesday 1.00 - 1.50
White Pass Precipitation (in)
Monday Night 0.75
Tuesday 0.75 -1.00
Tuesday Night 0.50
Wednesday 0.25 - 0.50
Washington Pass Precipitation (in)
Monday Night 1.50 - 2.00
Tuesday 1.00
Tuesday Night LT 0.25
Wednesday LT 0.25
Mission Ridge Precipitation (in)
Monday Night 0.25
Tuesday LT 0.25
Tuesday Night 0.50
Wednesday 0.25
Salmon la Sac - Gallagher Head Precipitation (in)
Monday Night 0.75
Tuesday 1.00
Tuesday Night 0.50
Wednesday 0.25
Tieton River - Darland Mt. Precipitation (in)
Monday Night 0.50
Tuesday 0.50
Tuesday Night 0.25 - 0.50
Wednesday 0.25
Mt Hood Meadows Precipitation (in)
Monday Night 0.25
Tuesday 1.50
Tuesday Night 1.00
Wednesday 1.00
Timberline Precipitation (in)
Monday Night 0.25
Tuesday 1.00 - 1.50
Tuesday Night 1.00
Wednesday 1.00

Issued: 2:09 PM PST Monday, December 4, 2023

Snow Level (ft)

Monday Evening* Monday Night* Tuesday Morning* Tuesday Afternoon Tuesday Evening Tuesday Night Wednesday Morning* Wednesday Afternoon
Olympics 10000' 9000' 6500' 6000' 5500' 5000' 4000' 4000'
West North 8500' 8500' 6500' 5500' 5000' 5000' 3500' 3000'
West Central 9000' 9000' 7500' 6000' 6000' 5500' 4000' 3000'
West South 9000' 9500' 8500' 7000' 7000' 6000' 5000' 4000'
Stevens Pass 8500' 9000' 8000' 6500' 6500' 6500' 5500' 3000'
Snoqualmie Pass 8500' 9000' 8000' 7500' 7000' 6500' 5000' 3000'
East North 5500' 6500' 7000' 6500' 5500' 5000' 4500' 3500'
East Central 8500' 9000' 8500' 7000' 7000' 6500' 6000' 4000'
East South 9000' 9500' 9000' 7500' 7500' 6500' 6000' 4000'
Mt. Hood 10000' 10000' 10000' 9000' 7500' 7000' 6000' 4000'
Olympics Elevation
Monday Evening* 10000'
Monday Night* 9000'
Tuesday Morning* 6500'
Tuesday Afternoon 6000'
Tuesday Evening 5500'
Tuesday Night 5000'
Wednesday Morning* 4000'
Wednesday Afternoon 4000'
West North Elevation
Monday Evening* 8500'
Monday Night* 8500'
Tuesday Morning* 6500'
Tuesday Afternoon 5500'
Tuesday Evening 5000'
Tuesday Night 5000'
Wednesday Morning* 3500'
Wednesday Afternoon 3000'
West Central Elevation
Monday Evening* 9000'
Monday Night* 9000'
Tuesday Morning* 7500'
Tuesday Afternoon 6000'
Tuesday Evening 6000'
Tuesday Night 5500'
Wednesday Morning* 4000'
Wednesday Afternoon 3000'
West South Elevation
Monday Evening* 9000'
Monday Night* 9500'
Tuesday Morning* 8500'
Tuesday Afternoon 7000'
Tuesday Evening 7000'
Tuesday Night 6000'
Wednesday Morning* 5000'
Wednesday Afternoon 4000'
Stevens Pass Elevation
Monday Evening* 8500'
Monday Night* 9000'
Tuesday Morning* 8000'
Tuesday Afternoon 6500'
Tuesday Evening 6500'
Tuesday Night 6500'
Wednesday Morning* 5500'
Wednesday Afternoon 3000'
Snoqualmie Pass Elevation
Monday Evening* 8500'
Monday Night* 9000'
Tuesday Morning* 8000'
Tuesday Afternoon 7500'
Tuesday Evening 7000'
Tuesday Night 6500'
Wednesday Morning* 5000'
Wednesday Afternoon 3000'
East North Elevation
Monday Evening* 5500'
Monday Night* 6500'
Tuesday Morning* 7000'
Tuesday Afternoon 6500'
Tuesday Evening 5500'
Tuesday Night 5000'
Wednesday Morning* 4500'
Wednesday Afternoon 3500'
East Central Elevation
Monday Evening* 8500'
Monday Night* 9000'
Tuesday Morning* 8500'
Tuesday Afternoon 7000'
Tuesday Evening 7000'
Tuesday Night 6500'
Wednesday Morning* 6000'
Wednesday Afternoon 4000'
East South Elevation
Monday Evening* 9000'
Monday Night* 9500'
Tuesday Morning* 9000'
Tuesday Afternoon 7500'
Tuesday Evening 7500'
Tuesday Night 6500'
Wednesday Morning* 6000'
Wednesday Afternoon 4000'
Mt. Hood Elevation
Monday Evening* 10000'
Monday Night* 10000'
Tuesday Morning* 10000'
Tuesday Afternoon 9000'
Tuesday Evening 7500'
Tuesday Night 7000'
Wednesday Morning* 6000'
Wednesday Afternoon 4000'

Issued: 2:09 PM PST Monday, December 4, 2023

5000' Temperatures (°F)

Monday Night Tuesday
Max / Min Max / Min
Olympics 42 / 40 41 / 39
West North 43 / 41 40 / 36
West Central 44 / 42 40 / 36
West South 43 / 42 45 / 40
Stevens Pass 43 / 37 43 / 38
Snoqualmie Pass 43 / 38 44 / 39
East North 40 / 31 39 / 35
East Central 42 / 37 44 / 38
East South 44 / 41 45 / 40
Mt. Hood 44 / 42 46 / 40
Olympics 5000' Temperature Forecast
(Max / Min)
Monday Night 42 / 40
Tuesday 41 / 39
West North 5000' Temperature Forecast
(Max / Min)
Monday Night 43 / 41
Tuesday 40 / 36
West Central 5000' Temperature Forecast
(Max / Min)
Monday Night 44 / 42
Tuesday 40 / 36
West South 5000' Temperature Forecast
(Max / Min)
Monday Night 43 / 42
Tuesday 45 / 40
Stevens Pass 5000' Temperature Forecast
(Max / Min)
Monday Night 43 / 37
Tuesday 43 / 38
Snoqualmie Pass 5000' Temperature Forecast
(Max / Min)
Monday Night 43 / 38
Tuesday 44 / 39
East North 5000' Temperature Forecast
(Max / Min)
Monday Night 40 / 31
Tuesday 39 / 35
East Central 5000' Temperature Forecast
(Max / Min)
Monday Night 42 / 37
Tuesday 44 / 38
East South 5000' Temperature Forecast
(Max / Min)
Monday Night 44 / 41
Tuesday 45 / 40
Mt. Hood 5000' Temperature Forecast
(Max / Min)
Monday Night 44 / 42
Tuesday 46 / 40

Issued: 2:09 PM PST Monday, December 4, 2023

Ridgeline Winds (mph)

Monday Evening Monday Night Tuesday Morning Tuesday Afternoon
Olympics SW 25-35 SW 20-30 SW 20-30 SW 10-20
West North SSW 30-40 SSW 35-50 SSW 25-35 SSW 10-20
West Central SW 30-40 SW 30-40 SW 25-35 SW 10-20
West South SW 20-30 SSW 25-35 SW 20-30 SW 15-25
Stevens Pass SW 15-25 SW 20-30 SW 15-25 WSW 10-20
Snoqualmie Pass SSW 25-35 SW 35-50 SW 30-40 SW 15-25
East North SSW 25-35 SW 25-35 SW 20-30 SW 15-25
East Central SW 25-35 SW 25-35 WSW 25-35 SW 15-25
East South SW 15-25 SW 20-30 SSW 15-25 SW 15-25
Mt. Hood SW 35-50 SW 40-55 SW 35-50 SW 35-50
Olympics Ridgeline Winds (mph)
Monday Evening SW 25-35
Monday Night SW 20-30
Tuesday Morning SW 20-30
Tuesday Afternoon SW 10-20
West North Ridgeline Winds (mph)
Monday Evening SSW 30-40
Monday Night SSW 35-50
Tuesday Morning SSW 25-35
Tuesday Afternoon SSW 10-20
West Central Ridgeline Winds (mph)
Monday Evening SW 30-40
Monday Night SW 30-40
Tuesday Morning SW 25-35
Tuesday Afternoon SW 10-20
West South Ridgeline Winds (mph)
Monday Evening SW 20-30
Monday Night SSW 25-35
Tuesday Morning SW 20-30
Tuesday Afternoon SW 15-25
Stevens Pass Ridgeline Winds (mph)
Monday Evening SW 15-25
Monday Night SW 20-30
Tuesday Morning SW 15-25
Tuesday Afternoon WSW 10-20
Snoqualmie Pass Ridgeline Winds (mph)
Monday Evening SSW 25-35
Monday Night SW 35-50
Tuesday Morning SW 30-40
Tuesday Afternoon SW 15-25
East North Ridgeline Winds (mph)
Monday Evening SSW 25-35
Monday Night SW 25-35
Tuesday Morning SW 20-30
Tuesday Afternoon SW 15-25
East Central Ridgeline Winds (mph)
Monday Evening SW 25-35
Monday Night SW 25-35
Tuesday Morning WSW 25-35
Tuesday Afternoon SW 15-25
East South Ridgeline Winds (mph)
Monday Evening SW 15-25
Monday Night SW 20-30
Tuesday Morning SSW 15-25
Tuesday Afternoon SW 15-25
Mt. Hood Ridgeline Winds (mph)
Monday Evening SW 35-50
Monday Night SW 40-55
Tuesday Morning SW 35-50
Tuesday Afternoon SW 35-50

Issued: 2:09 PM PST Monday, December 4, 2023

Extended Weather Synopsis

Just as it's turning back to snow in the northern third of the region the precipitation rates decrease on Tuesday night. Meanwhile, the firehose re-loads and sags south. Theres uncertainty with this next round, but at least snow levels look to gradually cool off during the day on Wednesday. Many areas can expect continued moderate precipitation during the day.

Temperatures continue to slowly cool, and we should be back to snow at most trailhead locations by Wednesday evening.

 

Extended Snow Level (ft)

Wednesday Night Thursday Thursday Night Friday
West North 3000' 3000' 2000' 2000'
Snoqualmie Pass 3000' 3000' 2500' 2500'
Mt. Hood 4000' 3500' 3000' 3000'
West North Elevation
Wednesday Night 3000'
Thursday 3000'
Thursday Night 2000'
Friday 2000'
Snoqualmie Pass Elevation
Wednesday Night 3000'
Thursday 3000'
Thursday Night 2500'
Friday 2500'
Mt. Hood Elevation
Wednesday Night 4000'
Thursday 3500'
Thursday Night 3000'
Friday 3000'

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

Previous forecast from Dec 4, 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’.