Expect new snow today to increase the avalanche hazard. Pay attention to accumulations, and if you find more than about 8 inches of new and recent snow, or snow blowing off ridgelines, seek terrain with slope angles less than 35 degrees or terrain sheltered from the wind. Cracking in the new snow is a quick sign to seek out lower angle terrain.
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Above 6500 ft.
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5000-6500 ft.
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3500-5000 ft.
If weather forecast verifies, expect a variety of new snow instabilities and rising avalanche danger. On Monday, 3” to 10” of new snow accumulated, with an additional 2” to 7” forecast today. Slabs large enough to bury or injure you have formed in bigger terrain. Expect thicker, more dangerous slabs on the leeward side of ridgelines where winds have transported new snow in the past 24 hours. Seek terrain with slope angles less than 35 degrees if you see signs of cracking on steep test slopes.
Today's avalanche danger will hinge on the weather forecast, which calls for 2” to 7” of new snow. Weather models show that moderate wind speeds will reach the Swan and Flathead crest and then quickly dissipate beyond there. The combination of new snow and isolated drifting will create a hazard that should be easy to identify and manage. Utilize small test slopes and hand pits to assess how the new snow is bonding to old snow interfaces. The interface may be recent snow or a melt-freeze crust depending on your elevation and aspect. Snow will likely sluff of areas where it falls onto a melt freeze crust.
It may become easy to get caught up in paying attention to new snow instabilities or driven by the excitement of fresh snow, but keep in mind the dragon that lurks at the bottom of the snowpack in parts of the forecast region. Take a look at this diagram, which clearly illustrates the locations of recent natural avalanches that failed on persistent weak layers buried at the bottom of the snowpack. Deep Slab avalanches remain a concern in similar terrain: steep, upper-elevation slopes that face northwest to east to southeast in the Flathead Range and Glacier National Park.
Deep Slab avalanches are notoriously difficult to predict. They can propagate long distances, be remotely triggered, and are always destructive. This problem requires a healthy dose of patience. Safer riding conditions can still be found at upper elevations AWAY from leeward, rocky, alpine faces.
You will notice that we have removed the Deep Slab Avalanche problem from the Whitefish Range advisory. This decision resulted from a lack of avalanche activity and terrain characteristics. These avalanches have been failing on weak layers near the ground in upper elevation, craggy, alpine faces, like the ones found in the Flathead Range and Glacier National Park.
A stronger system impacts our region today, favoring the Swan Range. Snowfall heights will vary from 2” to 7”. Winds will be light gusting to moderate. The freezing line will hover around 3500 feet.
| Tuesday | Tuesday Night | Wednesday | |
|---|---|---|---|
| Cloud Cover: | Overcast | Mostly Cloudy | Mostly Cloudy |
| Temperatures: | 26 to 32 deg. F. | 20 to 23 deg. F. | 26 to 32 deg. F. |
| Wind Direction: | South | Southwest | Southwest |
| Wind Speed: | 16G28 | 11 | 16G32 |
| Snowfall: | 3" to 7" in. | 1" to 2" in. | 0 to 1" in. |
| Snow Line: | 3500' | 3000' | 2500' |
This forecast applies only to backcountry areas outside established ski area boundaries. The forecast describes general avalanche conditions and local variations always occur. This forecast expires at midnight on the posted day unless otherwise noted. The information in this forecast is provided by the USDA Forest Service who is solely responsible for its content.
