Dangerous avalanche conditions exist. Recent snow and yesterday's strong southwesterly to northwesterly winds have added load to a snowpack that has buried weak layers. Avalanches could occur in the form of wind slabs at the higher elevations or as persistent slabs at all elevations. Although natural avalanches have become unlikely, human triggered avalanches are likely today and could be triggered remotely. Cautious route finding and conservative decision making is essential for safe backcountry travel.
Recent snow could be triggered as wind slabs in steep terrain above 8500 feet. These sensitive soft slabs were formed during strong southwest to northwest winds and could have depths to two feet. These slabs may become more sensitive this afternoon as they are weakened by rapidly warming temperatures and direct sunlight.
Persistent weak layers of faceted snow exist throughout the backcountry. Above 9000 feet these weaknesses are less prevalent and less sensitive but, if initiated, the result could be very large hard slabs with depths of three to five feet. They will be more sensitive between 7500 and 9000 feet where they could be hard or soft and have depths of two to four feet. At the low elevations the structure of the snowpack is very poor. At these elevations, slabs will be sensitive and are likely to involve faceted snow to the ground with depths to two feet. The sensitivity of these slabs will also increase as temperatures warm and the snowpack adjusts to the recent load.
( Discussion is generated from the previous day's afternoon forecast. )A ridge of high pressure will be over the area tonight and through Wednesday. Expect morning fog and inversion conditions with valleys starting out near or below zero and mountains starting near ten degrees. Highs in the mid-twenties are forecast for all elevations. The general avalanche hazard will be Considerable above 7500 feet in the Southwest Trails and Teton areas and Moderate below that elevation. In the Togwotee Pass area, the danger will be Moderate. Wind slabs and persistent slabs could be triggered in all areas. The recently formed wind slabs could have depths to two feet at higher elevations. The chance for human triggered avalanches involving persistent weak layers of faceted snow exists at all elevations. Although less likely to initiate, very large hard slab avalanches could be triggered at higher elevations with depths to five in the Teton and Southwest Trails areas and to three feet in the Togwotee Pass area. At mid and lower elevations, the triggering of avalanches by a single person is more likely but they will also be smaller in size, particularly at the low elevations.
