Natural avalanche activity was reported in wind loaded terrain yesterday. Wind continued to drift the snow and thicken slabs that I expect to remain sensitive to human triggers today. The avalanche danger is CONSIDERABLE above 6000 feet. Be aware of the potential for small avalanches to stress deep weak layers resulting in deeper slides. Dig into the snow and look for weak layers that exists in the mid snow pack and choose less complex terrain where present.
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Above 6500 ft.
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5000-6500 ft.
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3500-5000 ft.
Yesterday, BNSF Avalanche Safety reported natural avalanche activity in their program area on a recently wind loaded slope. Wind speeds moderated overnight, but have been variable in direction over the past few days forming slabs on multiple aspects and on a variety of old surfaces. Avoid steep terrain where smooth, rounded features exist on the surface. Stick to more sheltered slopes while these slabs settle and strengthen.
There is a lot of variability across the advisory area in the snow pack structure. One consistency is that layers of weak snow exist in the lower to mid snow pack. We have seen very little avalanche activity associated with these layers this season and they have been stubborn in most stability tests. This makes these layers a low probability but high consequence scenario. Up to 20 inches of snow fell early in the week adding stress to these layers. Dig into the snow and look for weak layers in the snowpack. Where you find them, choose simple terrain and avoid areas where you are more likely to trigger a deeper avalanche like steep, shallow, rocky areas.
We are deeply saddened to report that a skier sustained fatal injuries in an avalanche accident on Stanton Mountain in Glacier National Park Thursday, 01/05/2017. We extend our most sincere condolences to the family and friends. FAC staff, along with Glacier National Park Rangers, vistited the site on Friday. We will provide a complete report of their findings within a few days.
Join us on Friday, January 13 at The Stonefly Lounge, in Coram, at 7:00 pm for a free, engaging, and entertaining 1 hour avalanche awareness presentation.
Yesterday, BNSF Avalanche Safety reported recent avalanche activity in the John F Stevens Canyon in wind loaded terrain. Recent storm slab avalanche activity was reported in an area known as Dorothy's in the southern Whitefish Range. We were in the Cascade Creek drainage in the Flathead Range and found remnant crown lines from storm slabs that released earlier in the week. Wind was calm in this area and we could only see minimal drifting on surrounding peaks.
Tuesday: Seth traveled to Kimmerly Basin and found 6 to 10 inches of new snow from the Sunday/Monday storm. Winds from the southwest were actively transporting snow on exposed slopes. A shallow snowpack with depth hoar, but little reaction in stability tests was found on a sw aspect while a much deeper, wind loaded snowpack was found on an east aspect. One to two feet of new and wind loaded snow was on top of a weaker layer of snow that fell on Saturday night. This layer failed and propagated with moderate to hard force and we suspect this is the same layer that failed in the natural avalanche that occurred adjacent to the pit location while we were in the pit.
Monday: BNSF Avalanche Safety toured in John F. Stevens Canyon. They observed an upside down snowpack as a result of the recent snowfall and wind-loading occuring on easterly aspects. In a snow pit at 6000 feet on a southeastern aspect they found a weak snowpack structure with multiple buried weak layers, including depth hoar at the ground. No avalanche activity was observed, but visibility was limited. Skiers in the Wahoo drainage in the Flathead Range found about 12 inches of new snow near 6000 feet and noted the shifting wind directions over the course of the day. They also did not observe any avalanches, but the storm snow was reactive in a snow pit, with propagation in an extended column test with easy force (one tap).
See below for all observations this season.
Yesterday's clear skies and sub-zero temperatures are starting to feel pretty normal this season. We remain under a temperature inversion this morning so current mountain temperatures are slightly warmer than the valley ranging from -3-9º F. Winds are light out of the south and southeast. Today, expect partly cloudy skies with temperatures climbing to the mid teens. Winds will blow out of the south and southwest at 5-15 mph with gusts in the mid-20s particularly near the Continental Divide.
| 0600 temperature: | 0-9 deg. F. |
| Max. temperature in the last 24 hours: | 7-17 deg. F. |
| Average wind direction during the last 24 hours: | Variable |
| Average wind speed during the last 24 hours: | 5-10 mph |
| Maximum wind gust in the last 24 hours: | 12-20 mph |
| New snowfall in the last 24 hours: | 0 inches |
| Total snow depth: | 54-73 inches |
| Thursday | Thursday Night | Friday | |
|---|---|---|---|
| Cloud Cover: | Partly sunny and cool. | Cold and clear. | Mostly clear and cool. |
| Temperatures: | 3-14 deg. F. | -17-3 deg. F. | 7-19 deg. F. |
| Wind Direction: | South - Southwest | Southwest | Southwest |
| Wind Speed: | 6-8 gusts 21 | 6-8 gusts 20 | 5-9 gusts 20 |
| Snowfall: | 0 in. | 0 in. | 0 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.
