Tetons

The General Avalanche Hazard this morning is LOW at the Mid and Higher elevations and MODERATE at the low elevations.The Hazard will increase to MODERATE at Mid elevations as the day warms. Warm overnight lows and some rain have kept the snow warm at Mid elevations and lower. Yesterday a snowcat clearing the South Pass Traverse at the closed Jackson Hole Resort triggered a large wet slide that ran 2000 vertical feet(Buffalo Bowl, 8000', SE aspect). The start was a four foot slab that rapidly dissolved and entrained large amounts of debris.The bed surface was a saturated snow layer at the tops of evergreen brush (cyanothus). The free water in the snow showed there is NO strength and the snow sits in a fragile equilibrium between liquid and solid phases waiting for a shock (skier) to send it downhill. At elevations above 8500 to 9000 feet the deeper snow is still mostly dry and travellers should concern themselves with the upper two feet of the warm snow where wet slides are possible.

The first impulse of a powerful Spring storm system will move through the region tonight and Sunday. Four to six inches of new snow are expected at higher elevations by Sunday night. Snow levels should remain near 7500 feet. AVALANCHE HAZARD FORECAST FOR THE TETON, TOGWOTEE PASS, AND SOUTHWEST TRAILS AREAS:The General Avalanche Hazard tomorrow will be MODERATE as little overnight cooling is expected and new snow will easily slough off the crusts. As the day warms the possibility of slides growing to dangerous sizes will rise. The danger from large, wet loose slides at Mid to Low elevations will increase with rain and warming.