During the last few days, skiers and riders have been triggering many surface slabs with some very close calls. Yesterday a skier was carried and not buried by a slide in the Tetons, a snowboarder avoided being carried when he was able to dig into the bedsurface on Togwotee Pass, and snowmachiners were not caught but triggered hard slabs in the Wyoming range. On Wednesday a skier was hospitalized when a slide swept him into trees on Snow King mountain. The sensitivity of these wind formed slabs has decreased and although the hazard is now rated at Moderate, the chance continues for a single person to trigger similar events. This likelihood will increase in the afternoon as warm temperatures makes them more sensitive and also provides for the possibility of wet slides.
Recently formed surface slabs lie upon slick sun crusts and faceted snow. Above 7,500 feet, backcountry travelers could trigger these slabs to depths of one to two feet in steep, avalanche-prone terrain. Below 7,500 feet, skiers and riders might be able to trigger similar slides, but with shallower depths.
( Discussion is generated from the previous day's afternoon forecast. )Friday looks to be partly to mostly cloudy and slightly warmer with temperatures in the mid thirties expected at 9000 feet. West to southwest winds are to be strong with averages over thirty miles per hour. These winds will limit rapid heating of the snow surface in high terrain, however warming will still make current slabs more sensitive to human triggers in the afternoon. These slabs lie on all aspects in the backcountry and although the snowpack is adjusting and gaining strength, slabs that have formed since Sunday night could be triggered in steep wind loaded avalanche terrain to depths up to two feet. The general avalanche hazard will be rated as MODERATE.
