Good morning. This is Mark Staples with early season snowpack information issued Saturday, November 12 at 7:30 a.m. Today’s information is sponsored by Mystery Ranch in partnership with the Friends of the Avalanche Center. This information will be updated as conditions change.
After last weekend's snow and a week of dry weather, more snow is coming today. 3-4 inches has already fallen in the mountains near West Yellowstone and Cooke City, and snowfall today should favor these areas. Yesterday ahead of this storm, winds increased and were blowing 20-50 mph from the S and SW. They have calmed slightly but should remain fairly strong through the weekend and slowly shift to the W and NW. Temperatures this morning are in the mid 20s F but should drop as the day progresses.
Weather this fall has been relatively warm and dry, but snow on high elevation, N facing slopes has been sitting on the ground for nearly a month. We suspected this snow had become faceted, and I confirmed this suspicion yesterday on Sphinx Mountain just south of Big Sky. My partner and I found sugary, faceted snow capped by fresh wind slabs (photo). On a small test slope we easily triggered one of these wind slabs (photo). Hoping this was an isolated problem, we continued hiking but eventually turned around when we discovered this problem was widespread on N facing slopes. In October 2004, two ice climbers died in a very small avalanche when it swept them over a cliff in this same area. Additionally, a skier just outside the advisory area found a natural avalanche last weekend (photo).
Conditions can vary widely at this time of year, but there are several things worth considering. Southerly winds yesterday and this morning have loaded many N facing slopes where the weakest snow exists. With more snow and wind today, these areas should become prime places to trigger avalanches. Unfortunately these same slopes are perhaps ones with the best snow for skiing or the best ice for climbing. Hunters who often travel alone should avoid gullies or open slopes with any amount of wind drifted snow and consider traveling with a partner.
If you have any snowpack or avalanche observations, drop us a line at mtavalanche@gmail.com or call us at 587-6984.
Wednesday, November 16, BIG SKY
Avalanche Awareness talk at Grizzly Outfitters, 7 p.m.
Thursday, November 17, BOZEMAN
Avalanche Awareness talk at Northern Lights Trading Company, 7 p.m.
Thursday, November 17, BILLINGS
Avalanche Awareness talk at the Basecamp, 6:30 p.m.
Wednesday, November 30, BOZEMAN
Introduction to Avalanches with Field Course at MSU. Wed and Thur evening lectures with a field course on Saturday. More info at http://www.mtavalanche.com/education