Rapidly accumulating new snow and strong westerly winds are forming new wind slabs on steep leeward terrain features. In addition to this new snow problem, this added load will further stress buried weak layers that are well preserved within the snowpack. The size and sensitivity of both new and old hazard will increase as they are further loaded today. These avalanche concerns are most relevant in steep terrain above 7500 feet. Avalanches below that elevation are unlikely today except in isolated pockets in the steepest terrain.
Strong winds are forming new soft slabs in leeward terrain. These slabs will be small in the morning but could increase to having depths of 12 inches later in the day.
Poor snowpack structure is widespread on Togwotee Pass. Basal facets, near-surface facets, surface hoar, and crusts all persist in the snowpack. On a variety of aspects above 7,500 feet, skiers and riders still have the potential to trigger persistent slab avalanches with depths between 1 and 3 feet. Large triggers, such as snowmobiles, are more likely to initiate one of these slabs.
( Discussion is generated from the previous day's afternoon forecast. )Snow is to develop by midnight, continue during the day and diminish to snow showers by evening. In the Tetons, accumulations of 3-6 inches are expected by sunrise with another 2-4 to fall during the day. The Togwotee and Southwest Trails areas will see slightly less accumulations. Temperatures at high elevations are to fall to the teens overnight with highs tomorrow in the low twenties. Winds are to increase to averages between 20 and 30 mph as the snowfall begins. They will also veer from the southwest to northwest as the system passes and colder air moves in Wednesday night. In the Tetons, the general avalanche danger will remain Considerable above 9000 feet and Moderate below that elevation. If predicted snowfall and winds validate, then new wind slabs will start small and grow in size and sensitivity as the day progresses in terrain above 8000. This load will also increase the chances the chances for humans to trigger persistent slabs involving the recently active layers buried in late January. In the Togwotee and Southwest Trails areas, conditions differ in that the snowpack is weaker overall and contains more faceted layers. Less action has occurred in these areas due to less snow being received in recent storms however that could change rapidly if a significant storm were to impact them. Tomorrow, less snow is expected in these areas and although small wind slabs will likely develop and slides involving deeper layers remain susceptible to human triggers the rating will remain as Moderate above 7500 feet and low below that elevation where avalanches are unlikely except for in isolated pockets.
