Issued: 2:00 PM PST Sunday, December 15, 2024
by Dallas Glass

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

Weather Synopsis

It's a nice afternoon around most of the forecast region with generally lighter winds, sun breaks, or even large patches of blue sky. Light snow showers continue to linger near Mt Baker, but even these should soon draw to a close. Our next storm system is already knocking at the door with high clouds moving into Oregon and southwestern Washington. 

While most locations will see a similar pattern in the weather, timing will be very different from place to place. This storm arrives in the southern Olympics and south Cascade volcanoes this evening, before moving to near I-90 around midnight, and finally making its way to the Canadian border in the early morning hours. With more southerly flow, this storm will do well along both sides of the range, with slightly less accumulation in the passes. Expect clouds to thicken and lower ahead of the precipitation. With cold air in place, this should mainly be a snow event for common winter trailheads. Look for moderate to strong and gusty southerly winds to increase with the arrival of the bulk of the precipitation. This is a pretty compact storm. Once it washes through, winds will turn more westerly and decrease. Areas in the southern half of the region could see clouds start to part as we once again enter a relative calm between storms. 

Starting Monday night into Tuesday, things get messy. Heavier precipitation stays focussed from Mt Hood south down into Oregon. Weather models have a wide range of opinions on what happens next. The main flow of moisture should slowly start to drift northward connecting with a low-pressure system well to our north. Exactly when this happens and how far the moisture tap moves will have massive impacts on how much precipitation we receive. Areas further south have the best chance of additional rain and snow, but they could also see slight warmer temperatures. We'll have to keep watching this one. 

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
Sunday Night Increasing clouds. Rain and snow arriving in the southern Olympics in the later evening and near Hurricane Ridge in the very early morning hours. S winds becoming moderate and gusty.
Monday Cloudy with some rain and snow mainly in the morning. A few sun breaks possible in the afternoon. Moderate SW winds decreasing.
Sunday Night Partly to mostly clear in the evening, then becoming cloudy. A few snow showers in the early morning hours. SSE winds becoming light to moderate.
Monday Snow in the morning could be moderate to occasionally heavy. Gusty moderate S winds turning SW and decreasing.
Sunday Night Partly to mostly clear in the evening, then becoming cloudy. A few snow showers in the early morning hours. SSE winds becoming moderate.
Monday Cloudy with snow, heaviest in the morning. Light to moderate S winds turning SW and decreasing.
Sunday Night Clouds lowering and thickening. Precipitation arrives at Mt St Helens in the late evening and near Mt Rainier closer to midnight. SE winds becoming moderate and gusty.
Monday Cloudy with snow mainly in the morning. Showers with sun breaks in the afternoon. Light to moderate S winds turning SW and decreasing.
Sunday Night Clouds thickening and lowering overnight. A few showers in the very early morning hours. SE ridgeline winds becoming light to moderate. Light east flow at pass level.
Monday Cloudy with snow, tapering in the afternoon. SE ridgeline winds becoming light to moderate. Light east flow at pass level.
Sunday Night Clouds thickening and lowering with snow likely arriving after midnight. SE winds becoming moderate and gusty. Light easterly flow at pass level.
Monday Cloudy with snow mainly in the morning. Showers with sun breaks possible in the afternoon. Light to moderate SE ridgeline winds turning SW and decreasing. Light east flow at pass level.
Sunday Night Mostly clear with low clouds and valley fog. Increasing clouds with a few showers possible in the early morning hours, especially in the southern and eastern portions of the zone. Winds becoming SE light to moderate.
Monday Cloudy with snow showers. Could be the heaviest in the eastern mountains. Light to moderate SE winds turning S and decreasing.
Sunday Night Clouds thickening and lowering overnight snow heaviest in the Enchantment Wenatchee mountains arriving around midnight. S winds becoming moderate but gusty.
Monday Cloudy with snow mainly in the morning. Showers with possible sun breaks in the afternoon. Light to moderate S winds turning WSW.
Sunday Night Clouds thickening and lowering overnight. Snow increasing. S winds becoming moderate and gusty.
Monday Snow showers mainly in the morning. Then cloudy with sun breaks in the afternoon. Light to moderate SW winds.
Sunday Night Cloudy with snow increasing in intensity overnight. Could be heavy at times. SW winds increasing and becoming moderate to strong and gusty.
Monday Cloudy in the morning with lingering snow showers. Mostly cloudy with sun breaks and showers possible in the afternoon. Moderate to strong and gusty SW winds turning W.

Issued: 2:00 PM PST Sunday, December 15, 2024

Precipitation (in)

Sunday Night Monday Monday Night Tuesday
4 pm - 4 am 4 am - 4 pm 4 pm - 4 am 4 am - 4 pm
Hurricane Ridge LT 0.10 LT 0.25 LT 0.10 0.25 - 0.50
Mt Baker Ski Area LT 0.10 0.50 - 0.75 LT 0.10 0.25
Mt. Loop - Barlow Pass LT 0.10 0.50 LT 0.10 0.50 - 0.75
Stevens Pass LT 0.10 0.25 LT 0.25 0.25 - 0.50
Snoqualmie Pass LT 0.25 0.50 0.25 0.50
Crystal Mt 0.25 0.25 - 0.50 0.25 0.25 - 0.50
Paradise 0.25 - 0.50 0.25 - 0.50 0.25 - 0.50 0.75 -1.00
White Pass 0.25 0.25 0.25 0.50
Washington Pass LT 0.10 0.25 0 0.25
Mission Ridge LT 0.25 0.25 LT 0.25 0.25
Salmon la Sac - Gallagher Head 0.25 0.25 LT 0.25 0.25 - 0.50
Tieton River - Darland Mt. 0.25 0.25 0.25 0.25 - 0.50
Mt Hood Meadows 1.00 0.50 - 0.75 1.00 - 1.50 0.75 -1.00
Timberline 1.00 0.50 - 0.75 1.50 0.75 -1.00
Hurricane Ridge Precipitation (in)
Sunday Night LT 0.10
Monday LT 0.25
Monday Night LT 0.10
Tuesday 0.25 - 0.50
Mt Baker Ski Area Precipitation (in)
Sunday Night LT 0.10
Monday 0.50 - 0.75
Monday Night LT 0.10
Tuesday 0.25
Mt. Loop - Barlow Pass Precipitation (in)
Sunday Night LT 0.10
Monday 0.50
Monday Night LT 0.10
Tuesday 0.50 - 0.75
Stevens Pass Precipitation (in)
Sunday Night LT 0.10
Monday 0.25
Monday Night LT 0.25
Tuesday 0.25 - 0.50
Snoqualmie Pass Precipitation (in)
Sunday Night LT 0.25
Monday 0.50
Monday Night 0.25
Tuesday 0.50
Crystal Mt Precipitation (in)
Sunday Night 0.25
Monday 0.25 - 0.50
Monday Night 0.25
Tuesday 0.25 - 0.50
Paradise Precipitation (in)
Sunday Night 0.25 - 0.50
Monday 0.25 - 0.50
Monday Night 0.25 - 0.50
Tuesday 0.75 -1.00
White Pass Precipitation (in)
Sunday Night 0.25
Monday 0.25
Monday Night 0.25
Tuesday 0.50
Washington Pass Precipitation (in)
Sunday Night LT 0.10
Monday 0.25
Monday Night 0
Tuesday 0.25
Mission Ridge Precipitation (in)
Sunday Night LT 0.25
Monday 0.25
Monday Night LT 0.25
Tuesday 0.25
Salmon la Sac - Gallagher Head Precipitation (in)
Sunday Night 0.25
Monday 0.25
Monday Night LT 0.25
Tuesday 0.25 - 0.50
Tieton River - Darland Mt. Precipitation (in)
Sunday Night 0.25
Monday 0.25
Monday Night 0.25
Tuesday 0.25 - 0.50
Mt Hood Meadows Precipitation (in)
Sunday Night 1.00
Monday 0.50 - 0.75
Monday Night 1.00 - 1.50
Tuesday 0.75 -1.00
Timberline Precipitation (in)
Sunday Night 1.00
Monday 0.50 - 0.75
Monday Night 1.50
Tuesday 0.75 -1.00

Issued: 2:00 PM PST Sunday, December 15, 2024

Snow Level (ft)

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

Issued: 2:00 PM PST Sunday, December 15, 2024

5000' Temperatures (°F)

Sunday Night Monday
Max / Min Max / Min
Olympics 28 / 22 28 / 26
West North 27 / 20 27 / 24
West Central 28 / 20 28 / 22
West South 28 / 23 29 / 25
Stevens Pass 27 / 20 26 / 21
Snoqualmie Pass 28 / 21 26 / 22
East North 21 / 15 24 / 17
East Central 25 / 19 27 / 21
East South 28 / 23 30 / 22
Mt. Hood 30 / 25 31 / 27
Olympics 5000' Temperature Forecast
(Max / Min)
Sunday Night 28 / 22
Monday 28 / 26
West North 5000' Temperature Forecast
(Max / Min)
Sunday Night 27 / 20
Monday 27 / 24
West Central 5000' Temperature Forecast
(Max / Min)
Sunday Night 28 / 20
Monday 28 / 22
West South 5000' Temperature Forecast
(Max / Min)
Sunday Night 28 / 23
Monday 29 / 25
Stevens Pass 5000' Temperature Forecast
(Max / Min)
Sunday Night 27 / 20
Monday 26 / 21
Snoqualmie Pass 5000' Temperature Forecast
(Max / Min)
Sunday Night 28 / 21
Monday 26 / 22
East North 5000' Temperature Forecast
(Max / Min)
Sunday Night 21 / 15
Monday 24 / 17
East Central 5000' Temperature Forecast
(Max / Min)
Sunday Night 25 / 19
Monday 27 / 21
East South 5000' Temperature Forecast
(Max / Min)
Sunday Night 28 / 23
Monday 30 / 22
Mt. Hood 5000' Temperature Forecast
(Max / Min)
Sunday Night 30 / 25
Monday 31 / 27

Issued: 2:00 PM PST Sunday, December 15, 2024

Ridgeline Winds (mph)

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

Issued: 2:00 PM PST Sunday, December 15, 2024

Extended Weather Synopsis

The uncertainty for Tuesday bleeds into the extended forecast. Some models show a firehose pointing at the Pacific Northwest. Others quickly move the focus of the precipitation into British Columbia and spare us what could be quite the soaking of rain. A few even show two waves of precipitation with warming temperatures. While there is very little agreement, the common themes seem to be our region will be much warmer than the past few days and likely very wet. How high will the rain reach? We'll have to wait and see. 

Extended Snow Level (ft)

Tuesday Night* Wednesday Wednesday Night* Thursday *
West North 3000' 5000' 5500' 6000'
Snoqualmie Pass 3000' 5500' 6500' 7000'
Mt. Hood 6500' 6000' 6500' 6500'
West North Elevation
Tuesday Night* 3000'
Wednesday 5000'
Wednesday Night* 5500'
Thursday * 6000'
Snoqualmie Pass Elevation
Tuesday Night* 3000'
Wednesday 5500'
Wednesday Night* 6500'
Thursday * 7000'
Mt. Hood Elevation
Tuesday Night* 6500'
Wednesday 6000'
Wednesday Night* 6500'
Thursday * 6500'

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

Previous forecast from Dec 15, 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’.