East facing aspect at 9,000 ft. Eric Knoff looks at weak facets above an ice crust. Could pose a future poblem with an increased load.
Overcast skies and mild temperatures have kept the new snow from this past weekend in good shape. Yesterday, Doug, Mark and I dug a pit north of Bridger Bowl and found three feet of well bonded snow. Our stability tests did not indicate any real weaknesses within the snowpack. We proceeded to ski Wolverine Cirque, north of Bridger Bowl and found soft stable conditions over the entire slope.
Thanks to the new snow skiers were hitting the slopes hard this weekend with no avalanche activity reported in our advisory area. The Bridgers and northern Gallatins have a relatively stable snowpack, however some facets and surface hoar developed on and near the surface before this storm. Mark Staples found a small layer of facets on both north and south facing aspects on Sacajewea in the northern Bridgers. A skier reported surface hoar in the Hyalite area in the northern Gallatins as well. Both the surface hoar and facets are shallowly buried and will pose the greatest threat on wind
Last Thursday 12-16 inches of new snow fell, immediately followed by strong winds over the weekend. Skiers were out in droves in the Bridger Range and a few folks triggered small avalanches. One slide was down low in Slushman's Drainage when a skier triggered a steep, windloaded slope that buried him to his chest inside the gully.
This hard slab avalanche was triggered by a cornice-drop on the east side of Ross Pass. Although small (about 50'wide), this slide is a good reminder to be wise around cornices and to respect micro terrain features as well. Photo: Beau Fredlund
November in Southwest Montana always seems to offer up a variety of conditions. Over the past few weeks I have talked to people who have participated in a wide range of outdoor activities varying from ice climbing and skiing to rock climbing and road biking all in the same day. Cold temps in the higher elevations have preserved the existing snowpack on northerly aspects above 8,000 ft. These north facing slopes have become weak and faceted creating a very unstable base for the new snow to fall on.
A wise, old avalanche expert once told me "More snow = more avalanches." Last week was no exception with several natural and human triggered avalanches occurring after both the Wednesday and Friday storms. In some cases these avalanches were confined to pockets of wind drifted snow. In other cases these were much larger avalanches likely breaking on a layer of snow from storms in early October. This layer probably faceted during warm sunny days and clear cold nights and became the weak layer responsible for this avalanche activity. Because snow coverage varies widely this time of year,
