Today's sunshine and warming conditions will be increasing the hazard and creating dangerous conditions. In steep wind loaded avalanche starting zones and cliff areas backcountry travelers could trigger small to large wind slabs. The sensitivity of these winds slabs to human triggers and the potential for them to release naturally will increase as the day warms. Warming temperatures will also increase the wet snow avalanche hazard. Small to large wet slides are likely to release naturally from steep sunlit slopes and cliff areas. These wet slides could shed off hanging snowfields and overhead cliff areas. The warming conditions will also increase the potential for dangerous deep slab avalanches to release naturally, be triggered by a surface slab or wet slide or be triggered by a human. Temperatures at 5 am this morning are generally 3 to 15 degrees warmer than yesterday at 5 am. Monitor conditions for increasing hazard and make travel plans that will get you off and out from under steep sunlit slopes before the hazard increases.
At the mid and upper elevations skiers and riders could trigger wind slab avalanche that are 1 to 3 feet deep. The likelihood of triggering these slabs will increase during the day, especially on sunlit aspects. Natural releases are possible.
The potential for very large deep slab avalanches to occur in the Teton area is less than our other forecast zones but cannot be ruled out, especially during the warmest portion of the day. If triggered these dangerous deep slab avalanches are likely to run long distances and be un-survivable. They could be 4 to 8 feet deep at the mid and upper elevations and 2 to 4 feet deep at the lower elevations. Natural releases are possible.
High pressure is to dominate. Expect mild temperature inversions in the morning and warmer highs at all elevations with temperatures at the 9000 feet reaching the low forties. All three forecast areas have the same problem types, wind slabs and deep persistent slabs, but they vary considerably in the extent and likelihood of those problems. In the Tetons, where the most snow was received, the chance of triggering a deep slab is becoming unlikely but it remains a slight possibility due to uncertainty associated with the forecast warm temperatures. Those warm temperatures will first weaken wind slab which, if triggered could then cause failure of deeper layers which could cause a very large avalanche. The danger will be Moderate in the morning and raise to Considerable in the afternoon. At Togwotee Pass, the snowpack is weaker and the triggering of deep layers is the primary concern. Just 2 days ago a snowmobile triggered an avalanche with an eight foot crown. Similar events remain possible, especially during the afternoon as warming weakens the snowpack. The danger will be Considerable above 8000 feet and Moderate below that elevation. In the Southwest Trails area, as has been the case a lot this season, it lies in between the other two areas. More snow has been received there than the Togwotee Pass area but not as much as in the Tetons. Triggering truly deep slab avalanches there is more likely than in the Tetons and they could be very large with depths to eight feet. As in the other areas, wind slabs also remain a threat. The danger rating there will also be Considerable and avalanches will be more sensitive to human triggers during the heat of the day.
