Today, the avalanche danger above 6000 feet on steep wind-loaded slopes is MODERATE and human triggered avalanches are possible. On all other slopes the avalanche danger is LOW. Remember, LOW danger does not mean NO danger. An avalanche can still be triggered during periods of LOW danger. Treat recent wind loaded terrain as suspect and carefully evaluate the snow pack and terrain before committing to any slope. See the advisory for the Whitefish Range here
?
Above 6500 ft.
?
5000-6500 ft.
?
3500-5000 ft.
Wind affected surface snow is found in isolated upper elevation locations of the Swan and Flathead Ranges along with southern Glacier Park. On Sunday morning moderate westerly winds affected select locations and formed fresh wind slabs on leeward aspects and cross-loaded mid slope terrain features. On Monday, light easterly winds loaded atypical slopes in southern Glacier Park and may have done the same elsewhere. Recent wind slabs are identified by a smooth, rounded appearance and the snow will look thicker than other areas. Be sure to carefully assess wind-loaded slopes before skiing or riding in them.
Given the recent test in the form of a substantial load added to the weak snow above and below the the December 9 rain crust it is unlikely to trigger an avalanche on this layer, but not impossible. In many recent observations this layer is decomposing and not producing results in stabilty tests, however it is still worth taking the time to dig into the snow and see how it is reacting in the areas that you are skiing or riding. In some locations in the Flathead Range, Glacier Park, and parts of the Swan Range we noted and have received observations of weak, sugary snow near the ground. This layer has not shown signs of instability in stability tests, but is also worth mentioning.
Tuesday, Erich and his partner traveled to Elk Mountain in southern Glacier Park. They reported that the overnight north through east winds had formed reactive thin wind slabs on southerly aspects (photo). They also noted that dense slabs had formed on easterly aspects during recent wind events (video, observation).
Tuesday, BNSF Snow Safety reported minimal results in stability tests on a southeast aspect at 6000 feet in John F. Stevens Canyon. At this location the December 9th rain crust was a 6+inch thick, knife hard, ice mass. Below this layer was weak depth hoar (observation).
Monday, skiers in the Middle Fork reported the recent storm snow as being right side up and the Dec 9th rain crust as decomposing. Stability was good except for minor sluffing on steeper slopes (observation).
On Sunday, we received a report from the ridgeline east of the Whitefish Mountain Resort ski area. Skiers reported surface snow in this area as light, deep and cohesionless and were able to observe wind transporting snow on Great Northern Mountain in the Flathead Range.
Saturday, skiers in the Stryker Ridge area of the northern Whitefish Range reported deep cohesionless snow with no signs of wind affect. They skied northeast aspects above 6000' and reported lots of sluffing of the surface snow but no other obvious signs of instability.
Todd and I headed into Noisy Basin in the Swan Range on Saturday. The snow was deep and unconsolidated (photo). When there were breaks in the clouds, we observed several natural loose, dry avalanches that had recently occurred in steep terrain. Very minimal, recent wind drifted snow on the ridge that we traveled, but evidence of recent wind-loading at higher elevations on surrounding peaks.
Also on Saturday, skiers in Canyon Creek and Half Moon, both in the southern Whitefish Range found deep, unconsolidated snow with no obvious sign of instability. The party on Half Moon noted weak, faceted snow near the ground that did not react in stability testing.
Visit our Observations page and our You Tube channel for more information from the entire season.
Please let us know what you are seeing out there. Your observations are important and valued.
HOW TO SUBMIT OBSERVATIONS:
Email: [email protected]
Call and leave a message: 406.387.3821
You can also submit quick observations via text: 406.241.4571 (FAC mobile)
OR
Submit Snowpack Observations: http://www.flatheadavalanche.org/node/add/snowobs
Submit Avalanche Observations: http://www.flatheadavalanche.org/node/add/avyobs
Yesterday, light winds shifted from an easterly direction back to a westerly flow. Snowfall was minimal with accumulations of up to 2 inches of low density snow. Currently, temperatures above 6000 feet range from 4º-14º F and winds are out of the southwest though northwest at 4-9 mph with gusts up to 10 mph. Today, only a few light flurries are expected with temperatures rising to the mid teens to lower 20's. Winds will be light out of the west at 5-9 mph.
| 0600 temperature: | 4-14 deg. F. |
| Max. temperature in the last 24 hours: | 15-22 deg. F. |
| Average wind direction during the last 24 hours: | southwest |
| Average wind speed during the last 24 hours: | 0-10 mph |
| Maximum wind gust in the last 24 hours: | 0-10 mph |
| New snowfall in the last 24 hours: | 0-2 inches |
| Total snow depth: | 51-65 inches |
| Wednesday | Wednesday Night | Thursday | |
|---|---|---|---|
| Cloud Cover: | A few snow flurries | Partial clearing | High pressure building |
| Temperatures: | 17-24 deg. F. | 2-12 deg. F. | 16-25 deg. F. |
| Wind Direction: | west | west | southwest |
| Wind Speed: | 4-7 | 4-6 | 3-5 |
| 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.
