In addition to newly formed shallow wind slabs, the potential still exists for backcountry skiers and riders to trigger deep hard slab avalanches involving weak faceted snow near the base of the snowpack. These deep slabs will be larger, more sensitive, and more widely distributed above 7500 feet where conditions remain dangerous and cautious terrain choices are recommended. If considering steeper terrain, careful snowpack evaluation is essential as large avalanches could still be triggered in areas where the weak layer is present if a particularly thin spot on a slope is impacted. Below 7500 feet avalanches are not expected except for small slabs in isolated areas where strong winds this morning have loaded steep starting zones.
At the higher elevations, shallow wind slabs could be triggered to depths to eight inches in steep leeward terrain that was loaded by very strong southwest winds this morning.
Persistent weak layers of faceted snow that formed during the extended dry periods in November and at the end of December continue to be a real threat to backcountry travelers. Many avalanches involving these layers have occurred over the last week. Above 7500 feet these slabs could have depths of four to seven feet. At low elevations, isolated pockets of slab could be triggered with depths of one to two feet.
( Discussion is generated from the previous day's afternoon forecast. )Another round of snow expected overnight is to bring five to ten inches of snow to the higher elevations by sunrise. Low elevations should see one to three inches. Lingering snow showers are possible on Wednesday. Mountain temperature are to become more seasonal with a low in the low teens in the morning followed by highs in the upper teens. Southwest winds are to average 20-25 mph overnight followed by 15-20 mph averages tomorrow. The general avalanche hazard at the higher elevations will remain Considerable in the Tetons and Southwest Trails areas and Moderate in the Togwotee Pass area. The chance continues in all areas for a single person to trigger deep and dangerous hard slabs if a particularly weak point on a slope is impacted. These slabs could have depths to eight feet in the Teton and Southwest Trails areas and five feet in the Togwotee pass area. Wind slabs are also expected tomorrow on steep leeward slopes near ridges and summits. The size of these soft slabs will be dependent on the amount of snow received overnight.
