GNFAC Avalanche Advisory for Tue Mar 14, 2017
RAIN
With rain comes avalanches. A drizzle will not affect the stability, but a hard rain would quickly weaken the snow and trigger avalanches. Heavy rain is not forecasted, but forecasts can be wrong. Rain is the starting pistol to get out of avalanche terrain; think, “Run, Forrest, run!” And really, who wants to be out in the rain anyway.
A cornice triggered avalanche on the east face of Mt. Abundance outside Cooke City. The party also witnessed a cornice breaking off on the northeast side of Miller Ridge. Cornices are big and easily triggered right now! Photo: P. Costain
Forecast link: GNFAC Avalanche Advisory for Tue Mar 14, 2017
Wet avalanches on road cuts or steep slopes at lower elevations are a clue that larger wet avalanches are possible on slopes getting sun or rain. Photo: D. Haluptzok
Forecast link: GNFAC Avalanche Forecast for Fri Mar 17, 2017
Surfing a large cornice chunk outside Cooke City.
Forecast link: GNFAC Avalanche Advisory for Tue Mar 14, 2017
From an email: "Our group spotted this huge cornice break on sunday 3/12 while skiing lines into Goose Creek. Its somewhat hard to tell, however the size of the cornice is about the size of a 500sq ft house. Aspect is NE, photo taken on top of Goose Creek headwall looking south." Photo: J. Black
GNFAC Avalanche Forecast for Mon Mar 13, 2017
Bridger Range Madison Range Gallatin Range
Lionhead area near West Yellowstone Cooke City
A skier had a very scary encounter when they fell into this hole behind a cornice in Hyalite. They were sure they were not on a cornice, but close enough. Stay as far from the leeward edge of ridgelines as possible. It can be difficult to determine where cornices end, and tempting to travel near them where the snow is more supportable. Warm temperatures will cause cornices to fall naturally, be easy to trigger, and open up holes behind them. Photo: E. Farley
Forecast link: GNFAC Avalanche Forecast for Mon Mar 13, 2017
GNFAC Avalanche Advisory for Sun Mar 12, 2017
Cooke City Lionhead area near West Yellowstone
Madison Range Southern Gallatin Range