The avalanche danger is MODERATE above 6000 feet. Recent snow and wind has formed fresh wind slabs on leeward aspects at upper elevation locations, particularly in the alpine terrain. Below 6000 feet the wet loose avalanche danger may rise throughout the day with warming temperatures. Pay attention to changing conditions and evaluate the snowpack and your terrain choices carefully.
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Above 6500 ft.
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5000-6500 ft.
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3500-5000 ft.
Upper elevation weather stations in our area reported several inches of snow as of Friday morning. Moderate winds, accompanied by strong gusts, drifted this new snow onto leeward aspects at favored windy locations during the day yesterday. In many locations this snow was deposited onto a rain crust or a relatively slippery layer of dense snow. Expect to find thin wind slabs on typical leeward slopes at upper elevations, particularly in the alpine terrain. Smooth rounded pillows near ridgelines is a tell tale sign of a wind slab. Cracks shooting out from under your skis or sled are a great indication of unstable snow and that wind-loaded slopes should be avoided.
Temperatures finally dropped below freezing at low and mid elevations last night which left us with a thin crust on the snow surface. Due to abundant recent rain the snow below this crust is moist. Because of unusual weather patterns this winter the structure of the low and mid elevation snowpack is poor. As the day progresses and this crust breaks down triggering a wet loose avalanche on a steep slope may become possible. These slides will be small but could be consequential around terrain trap features.
We have not observed or been informed of any avalanches occurring on the January 19th crust or any other persistent weak layer since late last week. However, in some places stability tests are still showing reactive results around the January 19 crust and, in isolated locations, the depth hoar at the base of the snowpack is reactive as well. Even though these layers have not produced any avalanches lately, it is still important to be aware that in some locations in the advisory area there is a poor snowpack structure with buried weak layers that may still be reactive. Because these weak layers do not always present obvious signs of instability, digging into the snowpack is the best way to determine their location and reactivity. Also you are more likely to find and/or trigger one of these weak layers in steep rocky terrain that typically has a more shallow snowpack.
We would like to thank all those who have been submitting observations recently. These observations are invaluable and improve our forecasts. Several observers have submitted reports from across the advisory area documenting the widespread avalanche activity from last week (see our Observations Page). Thank you!
Friday: Zach and Mark travelled to the Skookoleel Ridge area of the Whitefish Range. We noted up to 4 inches of dense snow on top of a rain crust at upper elevations. Stability test results in our snowpits showed instabilities within the new snow and around the February 8 rain crust. No propagation was observed in our tests.
Thursday: We were in the Whitefish Range east of Whitefish Mountain Resort (observation). Very foggy weather limited visibility but no recent avalanche activity was observed. Last week's rain crust was breaking down making for a little better skiing. Two snowpits, one a NNE aspect, and another on a SE aspect yielded no propagation on any layer and no fractures on the Jan 19th crust which was about 1 m below the surface. BNSF Avalanche Safety observed a few small wet loose avalanches in some of the terrain above the railroad in Southern Glacier Park.
Wednesday: Guy and Seth travelled to Red Meadow Lake in the Northern Swan Range where they found temperatures above freezing, variable surface snow conditions and evidence of natural avalanche cycle from the Frebruary 3-10 cycle. At least one of those avalanches ran on the January 19 crust (Avalanche Observation). We also received a public observation from Werner Peak that affirmed there is still instability associated with the January 19 crust (Snowpack Observation).
See below for all observations this season.
Clearing skies overnight have allowed temperatures to drop below freezing at all elevations. Currently, above 6000 feet, temperatures are 22-31°F with light winds out of the northeast at 3-12 mph with gusts of 5-18 mph. Today we will have a few light showers and mild conditions with temperatures in the low to mid 30s ºF above 6000 feet and into the low 40s ºF at elevations below this. Light to moderate south-southeast winds will continue through the day.
| 0600 temperature: | 22 -31 deg. F. |
| Max. temperature in the last 24 hours: | 30-35 deg. F. |
| Average wind direction during the last 24 hours: | west - southwest |
| Average wind speed during the last 24 hours: | 1-24 mph |
| Maximum wind gust in the last 24 hours: | 5-35 mph |
| New snowfall in the last 24 hours: | 0-2 inches |
| Total snow depth: | 77-97 inches |
| Saturday | Saturday Night | Sunday | |
|---|---|---|---|
| Cloud Cover: | Mild with a few showers. | Continued mild with light showers. | Continued mild with a few showers. |
| Temperatures: | 31-41 deg. F. | 23-30 deg. F. | 31-40 deg. F. |
| Wind Direction: | South-southeast | South | Southwest |
| Wind Speed: | 5-7 mph | 5-9 mph | 6-8 mph with gusts to 18 |
| Snowfall: | 0-1 in. | 1-3 in. | 0-1 in. |
| Snow Line: |
This advisory applies only to backcountry areas outside established ski area boundaries. This advisory describes general avalanche conditions and local variations always occur. This advisory expires at midnight on the posted day unless otherwise noted. The information in this advisory is provided by the USDA Forest Service who is solely responsible for its content.
