SOUTHWEST TRAILS/GREY'S RIVER AREA ARCHIVE Issued at 02/09/2017 06:49 Valid Until: 02/09/2017 23:59 Archived for an incident in eastern Idaho on this day. The forecast is from Jackson Wyoming and the region covered by this may not extend completely to the incident location, but the conditions should be accurately reflected. CURRENT CONDITIONS (Mountain Weather Past 24 Hours) At 10,400' Elevation: 5 AM Temp: 28 º F Max Temp: 28 Avg Wind Direction: Southwest Avg. Wind Speed: 30(es Max Wind Gust: 50 Location Snowfall/Prec. Total Snow Depth Total Snowfall At 9,330' Elevation (Commissary Ridge Plot) 5(est)"/ .6 105" 319" At 9,000' Elevation (Blind Bull Meadow Plot)) 5(est)"/ .6" 111" 276" At 6,300' Elevation (Box Y Ranch Plot) rain"/ .5" 69" 181" Mountain Weather Forecast for 02/09/2017 Continued snowfall and rain. Temperature Forecast for 8,000´-9,000´: Rising into the mid thirties as the snow line rises above 8000 feet. Ridge Top Wind Forecast for 10,000´: Southwesterly at 25-35 mph. Snowfall Expected Next 24 Hours: 6-12 AVALANCHE DANGER 5 - EXTREME GENERAL AVALANCHE ADVISORY The avalanche danger will rise from High to Extreme today. VERY DANGEROUS AVALANCHE CONDITIONS EXIST AND ALL AVALANCHE TERRAIN SHOULD BE AVOIDED TODAY. As a warm and wet system brings increasing temperatures and constant snow and rain to the area today, the avalanche hazard will continue to rapidly increase. Snowfall at the higher elevations will continue to load existing wind slabs, making them both larger and increasing the likelyhood of them releasing naturally. Below 8500 feet, rain will quickly weaken the snowpack, allowing for wet slabs to occur. These avalanches will release naturally today and given the above average snowpack, are likely to entrain large volumes of snow. One such slide has already occurred this morning in the Snake River Canyon near Wolf Creek, closing Snake River Canyon. Teton Pass remains closed as WYDOT continues to clean up debris from several slides that occurred two days ago. Also of note is that two snowmobilers were both uninjured after being caught in a slide at Togwotee yesterday. One was fully buried with the exception of a visible part of his airbag that he had deployed. Beware of run out zones at lower elevations and use cautions around buildings as roofs will also be sliding. An avalanche warning has been issued by the center effective 1am this morning and continuing through at least 1am Friday. TODAY'S AVALANCHE PROBLEMS Wind Slab Very strong southwest to west winds over the past week have formed slabs and continue to load slabs in the backcountry. These slabs could release on density breaks throughout the storm cycle with depths of six inches to as much as four feet at the higher elevations. These slabs will be very sensitive to human triggers and are likely to release naturally today at the mid and high elevations and once triggered could run long distances and entrain the wet snow at the lower elevations. Continued snowfall and the rising snow/rain line will increase their likelyhood of failure today. Above 9000 feet in northerly terrain a slight chance exists for these slides to cause failure to the base of the snowpack. Wet Slab The snowpack at the mid and low elevations will be quickly weakened by rain. Avalanche activity in the form of wet slab and wet loose is activity is certain.