The wet and wild weather will continue as we head into the holiday weekend. The first in a series of atmospheric rivers will continue to spread rain and high elevation snow from north to south across western Washington Thanksgiving night. The heaviest precipitation is expected around the Cascade Volcanoes and in a Puget Sound Convergence Zone which should take aim at areas from the Mountain Loop Highway to Snoqualmie Pass. Snow levels with this first storm will remain well above trailhead and pass levels. The notable exception is lingering pockets of colder air holding strong near the Canadian border, particularly in the Methow region. In addition to the warm temperatures and heavy precipitation, strong westerly winds in most areas will make for very storm conditions.
As we head into Friday, slightly cooler weather will begin to shift into the region. As it does so, most of the precipitation ends. Notable rain and snow should continue for locations near Mt Hood and where the convergence zone remains focussed. By mid-late afternoon, a brief break in the action should allow most locations to dry out as shower activity comes to an end. A few sun breaks could even be possible for areas east of the Cascade crest.
This break appears short-lived. A second, and slightly stronger, atmospheric river will begin to approach the region Saturday morning. Weather models disagree slightly with the timing of this system but generally agree on the major impacts and pattern. Moderate to heavy precipitation and strong winds will spread from NW to SE across the area Saturday afternoon. Locations in the Olympics and N. Cascades will see the most significant accumulations during the day, but as the storm continues, precipitation will spread further south. Very warm air should arrive with the onset of precipitation and send snow levels soaring. Right now, this appears to be yet another mostly rain and very high elevation snow event for the mountains.
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
Thursday
Night
Cloudy with rain becoming rain showers. Strong W winds decreasing slightly.
Friday
Mostly cloudy with isolated showers mainly in the morning. Light to moderate W winds.
Thursday
Night
Cloudy with rain and snow, becoming showers by morning. Moderate to strong SW winds.
Friday
Mostly cloudy with showers mainly in the morning. Moderate W winds decreasing.
Thursday
Night
Cloudy with moderate to heavy rain and high elevation snow. Puget Sound Convergence Zone bringing locally heavier precipitation. Moderate to strong SW winds.
Friday
Puget Sound Convergence Zone strongest in the morning, bringing locally heavier precipitation. Showers elsewhere. Moderate W winds decreasing.
Thursday
Night
Moderate to heavy rain and high elevation snow. Greatest accumulations near the volcanoes. Moderate to strong W winds.
Friday
Rain and high elevation snow showers, particularly in the morning. Heaviest precipitation near the volcanoes, particularly Mt St Helens and Mt Adams. Moderate W winds decreasing.
Thursday
Night
Cloudy with moderate to heavy rain and high elevation snow. Puget Sound Convergence Zone bringing locally heavier precipitation. Moderate W winds.
Friday
Puget Sound Convergence Zone, strongest in the morning, bringing locally heavier precipitation. Moderate W winds decreasing in the afternoon.
Thursday
Night
Cloudy with moderate to heavy rain and high elevation snow. Puget Sound Convergence Zone bringing locally heavier precipitation. Moderate to strong W winds decreasing slightly.
Friday
Puget Sound Convergence Zone, strongest in the morning, bringing locally heavier precipitation. Moderate W winds.
Thursday
Night
Mostly cloudy with rain and snow showers. Moderate to strong W winds.
Friday
Mostly cloudy with scattered rain and snow showers mostly in the morning. Moderate to strong W winds should decrease slightly in the afternoon.
Thursday
Night
Cloudy to mostly cloudy. Rain and snow, heaviest near the Cascade crest. Scattered showers in the Wenatchee Mts. Strong W winds.
Friday
Mostly to partly cloudy with showers lingering near the crest. Strong W winds should decrease slightly in the afternoon.
Thursday
Night
Cloudy with rain and high elevation snow showers, heaviest near the Cascade crest. Strong W winds.
Friday
Mostly to partly cloudy with lingering showers. Strong W winds should decrease slightly in the afternoon.
Thursday
Night
Cloudy. Rain and high elevation snow should become heavier around midnight. Strong W winds.
Friday
Rain and high elevation snow, heaviest in the morning, turning to showers in the afternoon. Strong W winds decreasing slightly.
Issued: 2:00 PM PST Thursday, November 25, 2021
Precipitation (in)
Thursday Night
Friday
Friday Night
Saturday
4 pm - 4 am
4 am - 4 pm
4 pm - 4 am
4 am - 4 pm
Hurricane Ridge
0.25 - 0.50
LT 0.10
0
0.50
Mt Baker Ski Area
1.00
0.25
0
1.00
Mt. Loop - Barlow Pass
1.50 - 2.00
0.25 - 0.50
0
0.50 - 0.75
Stevens Pass
1.50
0.25
0
0.25 - 0.50
Snoqualmie Pass
1.50 - 2.00
LT 0.25
0
0.25 - 0.50
Crystal Mt
0.50
LT 0.10
0
0.25
Paradise
1.50 - 2.00
0.25
0
0.50 - 0.75
White Pass
0.75
LT 0.25
0
0.25
Washington Pass
0.75
LT 0.25
0
0.25 - 0.50
Mission Ridge
0.25
LT 0.10
0
LT 0.10
Salmon la Sac - Gallagher Head
0.75 -1.00
LT 0.25
0
0.25
Tieton River - Darland Mt.
0.25 - 0.50
0.50
0
LT 0.25
Mt Hood Meadows
0.75
0.75
LT 0.10
0.25
Timberline
0.75 -1.00
0.75
LT 0.10
0.25
Hurricane Ridge
Precipitation (in)
Thursday Night
0.25 - 0.50
Friday
LT 0.10
Friday Night
0
Saturday
0.50
Mt Baker Ski Area
Precipitation (in)
Thursday Night
1.00
Friday
0.25
Friday Night
0
Saturday
1.00
Mt. Loop - Barlow Pass
Precipitation (in)
Thursday Night
1.50 - 2.00
Friday
0.25 - 0.50
Friday Night
0
Saturday
0.50 - 0.75
Stevens Pass
Precipitation (in)
Thursday Night
1.50
Friday
0.25
Friday Night
0
Saturday
0.25 - 0.50
Snoqualmie Pass
Precipitation (in)
Thursday Night
1.50 - 2.00
Friday
LT 0.25
Friday Night
0
Saturday
0.25 - 0.50
Crystal Mt
Precipitation (in)
Thursday Night
0.50
Friday
LT 0.10
Friday Night
0
Saturday
0.25
Paradise
Precipitation (in)
Thursday Night
1.50 - 2.00
Friday
0.25
Friday Night
0
Saturday
0.50 - 0.75
White Pass
Precipitation (in)
Thursday Night
0.75
Friday
LT 0.25
Friday Night
0
Saturday
0.25
Washington Pass
Precipitation (in)
Thursday Night
0.75
Friday
LT 0.25
Friday Night
0
Saturday
0.25 - 0.50
Mission Ridge
Precipitation (in)
Thursday Night
0.25
Friday
LT 0.10
Friday Night
0
Saturday
LT 0.10
Salmon la Sac - Gallagher Head
Precipitation (in)
Thursday Night
0.75 -1.00
Friday
LT 0.25
Friday Night
0
Saturday
0.25
Tieton River - Darland Mt.
Precipitation (in)
Thursday Night
0.25 - 0.50
Friday
0.50
Friday Night
0
Saturday
LT 0.25
Mt Hood Meadows
Precipitation (in)
Thursday Night
0.75
Friday
0.75
Friday Night
LT 0.10
Saturday
0.25
Timberline
Precipitation (in)
Thursday Night
0.75 -1.00
Friday
0.75
Friday Night
LT 0.10
Saturday
0.25
Issued: 2:00 PM PST Thursday, November 25, 2021
Snow Level (ft)
Thursday
Evening
Thursday
Night
Friday
Morning
Friday
Afternoon
Friday
Evening
Friday
Night*
Saturday
Morning*
Saturday
Afternoon*
Olympics
7500'
6500'
5500'
4500'
4500'
4500'
6500'
9500'
West North
5000'
5000'
4500'
4000'
4000'
3500'
4000'
7000'
West Central
6500'
6000'
5500'
5000'
5000'
4500'
5500'
8000'
West South
8000'
7000'
6000'
5500'
5500'
5500'
6500'
9000'
Stevens Pass
6500'
6000'
5500'
5000'
5000'
4500'
4000'
7500'
Snoqualmie Pass
7000'
7000'
6000'
5500'
5000'
5000'
5000'
8500'
East North
5500'
5000'
5000'
4500'
4000'
3000'
3000'
5000'
East Central
7000'
6500'
5500'
5000'
4500'
4000'
3500'
7500'
East South
8000'
7500'
6500'
5500'
5000'
5000'
5500'
9000'
Mt. Hood
9000'
8500'
7000'
6500'
6500'
6500'
7500'
9500'
Olympics
Elevation
Thursday
Evening
7500'
Thursday
Night
6500'
Friday
Morning
5500'
Friday
Afternoon
4500'
Friday
Evening
4500'
Friday
Night*
4500'
Saturday
Morning*
6500'
Saturday
Afternoon*
9500'
West North
Elevation
Thursday
Evening
5000'
Thursday
Night
5000'
Friday
Morning
4500'
Friday
Afternoon
4000'
Friday
Evening
4000'
Friday
Night*
3500'
Saturday
Morning*
4000'
Saturday
Afternoon*
7000'
West Central
Elevation
Thursday
Evening
6500'
Thursday
Night
6000'
Friday
Morning
5500'
Friday
Afternoon
5000'
Friday
Evening
5000'
Friday
Night*
4500'
Saturday
Morning*
5500'
Saturday
Afternoon*
8000'
West South
Elevation
Thursday
Evening
8000'
Thursday
Night
7000'
Friday
Morning
6000'
Friday
Afternoon
5500'
Friday
Evening
5500'
Friday
Night*
5500'
Saturday
Morning*
6500'
Saturday
Afternoon*
9000'
Stevens Pass
Elevation
Thursday
Evening
6500'
Thursday
Night
6000'
Friday
Morning
5500'
Friday
Afternoon
5000'
Friday
Evening
5000'
Friday
Night*
4500'
Saturday
Morning*
4000'
Saturday
Afternoon*
7500'
Snoqualmie Pass
Elevation
Thursday
Evening
7000'
Thursday
Night
7000'
Friday
Morning
6000'
Friday
Afternoon
5500'
Friday
Evening
5000'
Friday
Night*
5000'
Saturday
Morning*
5000'
Saturday
Afternoon*
8500'
East North
Elevation
Thursday
Evening
5500'
Thursday
Night
5000'
Friday
Morning
5000'
Friday
Afternoon
4500'
Friday
Evening
4000'
Friday
Night*
3000'
Saturday
Morning*
3000'
Saturday
Afternoon*
5000'
East Central
Elevation
Thursday
Evening
7000'
Thursday
Night
6500'
Friday
Morning
5500'
Friday
Afternoon
5000'
Friday
Evening
4500'
Friday
Night*
4000'
Saturday
Morning*
3500'
Saturday
Afternoon*
7500'
East South
Elevation
Thursday
Evening
8000'
Thursday
Night
7500'
Friday
Morning
6500'
Friday
Afternoon
5500'
Friday
Evening
5000'
Friday
Night*
5000'
Saturday
Morning*
5500'
Saturday
Afternoon*
9000'
Mt. Hood
Elevation
Thursday
Evening
9000'
Thursday
Night
8500'
Friday
Morning
7000'
Friday
Afternoon
6500'
Friday
Evening
6500'
Friday
Night*
6500'
Saturday
Morning*
7500'
Saturday
Afternoon*
9500'
Issued: 2:00 PM PST Thursday, November 25, 2021
5000' Temperatures (°F)
Thursday
Night
Friday
Max / Min
Max / Min
Olympics
38 / 35
38 / 31
West North
36 / 32
36 / 28
West Central
40 / 34
36 / 29
West South
41 / 34
39 / 33
Stevens Pass
39 / 35
36 / 31
Snoqualmie Pass
40 / 35
37 / 32
East North
35 / 33
36 / 27
East Central
39 / 35
36 / 31
East South
40 / 34
36 / 34
Mt. Hood
42 / 35
39 / 34
Olympics
5000' Temperature Forecast (Max / Min)
Thursday
Night
38 / 35
Friday
38 / 31
West North
5000' Temperature Forecast (Max / Min)
Thursday
Night
36 / 32
Friday
36 / 28
West Central
5000' Temperature Forecast (Max / Min)
Thursday
Night
40 / 34
Friday
36 / 29
West South
5000' Temperature Forecast (Max / Min)
Thursday
Night
41 / 34
Friday
39 / 33
Stevens Pass
5000' Temperature Forecast (Max / Min)
Thursday
Night
39 / 35
Friday
36 / 31
Snoqualmie Pass
5000' Temperature Forecast (Max / Min)
Thursday
Night
40 / 35
Friday
37 / 32
East North
5000' Temperature Forecast (Max / Min)
Thursday
Night
35 / 33
Friday
36 / 27
East Central
5000' Temperature Forecast (Max / Min)
Thursday
Night
39 / 35
Friday
36 / 31
East South
5000' Temperature Forecast (Max / Min)
Thursday
Night
40 / 34
Friday
36 / 34
Mt. Hood
5000' Temperature Forecast (Max / Min)
Thursday
Night
42 / 35
Friday
39 / 34
Issued: 2:00 PM PST Thursday, November 25, 2021
Ridgeline Winds (mph)
Thursday
Evening
Thursday
Night
Friday
Morning
Friday
Afternoon
Olympics
WSW 15-25
W 10-20
W 10-20
WSW 5-15
West North
SSW 20-30
WSW 15-25
W 15-25
W 5-15
West Central
SW 20-30
W 15-25
W 15-25
W 5-15
West South
WSW 20-30
W 20-30
W 15-25
W 10-20
Stevens Pass
WSW 10-20
W 10-20
W 10-20
W 5-15
Snoqualmie Pass
WSW 20-30
W 15-25
W 15-25
W 15-25
East North
WSW 20-30
W 20-30
W 20-30
W 15-25
East Central
WSW 30-40
W 30-40
W 30-40
W 20-30
East South
WSW 30-40
W 35-50
W 30-40
W 20-30
Mt. Hood
WSW 30-40
W 40-55
W 25-35
W 20-30
Olympics
Ridgeline Winds (mph)
Thursday
Evening
WSW
15-25
Thursday
Night
W
10-20
Friday
Morning
W
10-20
Friday
Afternoon
WSW
5-15
West North
Ridgeline Winds (mph)
Thursday
Evening
SSW
20-30
Thursday
Night
WSW
15-25
Friday
Morning
W
15-25
Friday
Afternoon
W
5-15
West Central
Ridgeline Winds (mph)
Thursday
Evening
SW
20-30
Thursday
Night
W
15-25
Friday
Morning
W
15-25
Friday
Afternoon
W
5-15
West South
Ridgeline Winds (mph)
Thursday
Evening
WSW
20-30
Thursday
Night
W
20-30
Friday
Morning
W
15-25
Friday
Afternoon
W
10-20
Stevens Pass
Ridgeline Winds (mph)
Thursday
Evening
WSW
10-20
Thursday
Night
W
10-20
Friday
Morning
W
10-20
Friday
Afternoon
W
5-15
Snoqualmie Pass
Ridgeline Winds (mph)
Thursday
Evening
WSW
20-30
Thursday
Night
W
15-25
Friday
Morning
W
15-25
Friday
Afternoon
W
15-25
East North
Ridgeline Winds (mph)
Thursday
Evening
WSW
20-30
Thursday
Night
W
20-30
Friday
Morning
W
20-30
Friday
Afternoon
W
15-25
East Central
Ridgeline Winds (mph)
Thursday
Evening
WSW
30-40
Thursday
Night
W
30-40
Friday
Morning
W
30-40
Friday
Afternoon
W
20-30
East South
Ridgeline Winds (mph)
Thursday
Evening
WSW
30-40
Thursday
Night
W
35-50
Friday
Morning
W
30-40
Friday
Afternoon
W
20-30
Mt. Hood
Ridgeline Winds (mph)
Thursday
Evening
WSW
30-40
Thursday
Night
W
40-55
Friday
Morning
W
25-35
Friday
Afternoon
W
20-30
Issued: 2:00 PM PST Thursday, November 25, 2021
Extended Weather Synopsis
The extended forecast begins in the middle of the 2nd of three atmospheric rivers forecasted to hit the Northwest over the next week. Widespread rain and very high elevation snow along with strong westerly winds should continue to impact the mountains Sunday night. As the firehose of precipitation shifts further south toward Oregon, slightly cooler air should enter the region allowing snow levels to slowly lower to around 5000-6500'. Some weather models draw additional moisture into this event, maintaining significant precipitation Sunday night and Monday. Others show a more steady decrease in shower activity. We'll have to wait and see how these two possibilities play out.
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).