Very strong winds and approximately three feet of snow received over the last four days have resulted in dangerous avalanche conditions above 8500 feet where wind slabs could be easily triggered in steep terrain and larger avalanches, involving older persistent weak layers could also occur. Natural avalanche activity is possible today on high exposed terrain, especially as winds veer to the northwest this afternoon. Cautious route finding is essential today. Be careful not to let the actions of others during this period of heavy holiday traffic impact decision making as these heightened avalanche conditions are real and demand respect. Avalanches remain unlikely below 8500 feet except for the possibility of small isolated events on very steep features.
Winds from the south to northwest have created sensitive soft slabs. Riders and skiers have the potential to trigger these slabs above 8500 feet although they will be most sensitive and larger along high elevation ridge crests and areas prone to wind loading. These slabs could have depths to three feet.
Weak, faceted snow from the December 5 interface could result in larger avalanches up to 5 feet in depth. The activity on this layer has been limited but the increased load over the past 3 days has added stress to the snowpack. These persistent slab avalanches could be triggered by the weight of a single person or the impact of a wind slab. Careful evaluation of the snowpack is essential for assessing this potential avalanche problem.
( Discussion is generated from the previous day's afternoon forecast. )Periods of moderate snowfall are expected to occur tonight and Monday as snow showers pass through the area. Another 4-8 inches of snow is expected in favored terrain by tomorrow night. Temperatures are to remain cold with mountain highs in the single digits. Winds are to average in the twenties but could have gusts into the fifties, particularly during precipitation events. The general avalanche danger will remain Considerable above 9000 feet in the Tetons and above 8500 feet in the Togwotee and Southwest Trails areas. Sensitive wind slabs could be easily triggered in steep wind loaded areas to depths of three feet. A lesser chance exists to initiate larger and more dangerous slabs with depths to five feet. Between 7500 and 9000 feet in the Tetons, the danger will be Moderate where similar avalanche problems exist although slabs will be smaller and less sensitive. Below 7500 feet in the Tetons and 8500 feet in the other areas, the avalanche danger will be Low and avalanche activity is unlikely except for in isolated pockets.
