Tetons

The second avalanche fatality of the season occured yesterday when backcountry skiers triggered a large slab avalanche at an elevation of about 10,000 feet on a northeast aspect on Mount Taylor in the southern end of the Teton Range. The crown of this slab was six feet deep and was triggered in the starting zone of a major avalanche path with an estimated slope angle of 40 degrees. On Beard Mountain (elevation 9,466 feet) another backcountry skier dropped a cornice on a northerly aspect which triggered a shallow surface slab that then stepped down to a depth of four feet and ran full track. Large natural avalanches with crown depths of four to eight feet, which likely occured Wednesday, were observed on Teewinot Mountain, Buck Mountain and two peaks east-southeast of Mount Oliver. Similar events are likely to be triggered today in the steep wind loaded starting zones of major avalanche paths. Todays mountain temperatures will be warmer then yesterday and will increase the sensitivity of these large dangerous slabs to triggers such as skiers, snowboarders and snowmachines. Clear skies and good visibility can encourage backcountry users to take greater risks. Good decision making skills are essential today.

A ridge of high pressure and the associated very warm airmass over the area will break down over the next 24 hours. The first in a series of Pacific storms will bring light valley rain and snow to the northwest mountains of Wyoming Saturday afternoon. Expect clouds to increase during the day as this precipitation develops. Mountain daytime highs will climb into the upper 20's to low 30's. Winds will be southwesterly at 16 to 25 MPH. AVALANCHE HAZARD FOR THE TETON, TOGWOTEE PASS/CONTINENTAL DIVIDE AND GREYS RIVER/SOUTHWEST TRAILS AREASThe general avalanche danger is expected to be MODERATE. Dangerous slabs could be triggered in very steep heavily wind drifted avalanche starting zones and have potential to run full path. Slabs to eight feet in depth have run primarily on east through north aspects. Some have been triggered by shallow surface slabs that have stepped down to deeper layers. Larger triggers such as snowmachines and groups are most likely to trigger these slabs. The consequences of an interaction with these slabs are likely to be severe! Backcountry users are advised to consult area specific forecasts issued every morning as new information may become available and unexpected weather can change conditions.