Updated at 11:25 AM ......Localized snowfall rates in excess of an inch per hour are increasing the general avalanche hazard to considerable. Impacted areas include the southern Teton Range and Teton Pass. The WYDOT is scheduled to conduct avalanche hazard mitigation efforts on Teton Pass at 8 PM tonight and will be closing parking areas beginning at noon .................................................................................................................................................................................................................................................................................................................................................................The National Weather Service has issued a Winter Weather Advisory for the Tetons through 8 PM tonight. Since yesterday afternoon, there have been 6 to 12 inches of new snow in the Tetons, and another 6 to 8 inches of snow is expected throughout the day. The additional snow, gusty ridgetop winds, and warming temperatures will increase the avalanche hazard. The new snowfall accompanied by moderate winds has formed wind slabs along ridges and specific terrain features. It is possible for backcountry travelers to trigger these slabs, which could step down 3 feet deep to persistent weak layers. In steep terrain and on south-facing slopes, where the new snow lies over sun crusts, slabs could be more easily triggered and loose snow sluffing will likely occur. Backcountry travelers should monitor the increasing hazard and plan accordingly.
Moderate southerly and southwesterly winds have formed wind slabs at the mid and upper elevations. These slabs will increase in sensitivity throughout the day and be 1 to 2 feet deep. Below 7,500 feet, small isolated slabs on steep terrain features are possible and will increase in size and sensitivity throughout the day.
Moisture will continue to flow into region. A brief decrease in snowfall intensity is anticipated overnight with the main accumulation across Yellowstone Park and the far northern Tetons. Increased snowfall rates will return in the morning and spread south into the Salt River and Wyoming Ranges by early afternoon. Overall additional accumulations of 5 to 10 inches are anticipated in the Tetons with 4 to 8 inches expected in the Salt River and Wyoming Ranges. Temperatures will continue to climb further into the 20s in the mountains on Friday. Valley’s will reach 30 degrees. Winds will be from the south to southwest at 5 to 20 miles per hour.The general avalanche hazard is expected to be moderate in the Greys River and Togowtee Pass areas. In those areas, humans could trigger persistent slab avalanches one to four feet deep on steep avalanche prone slopes. More snow and warming temperatures are likely to keep the avalanche hazard at considerable in the areas of the Teton Range that were slammed by snow today. In those areas dangerous sluffs and large slab avalanches could by human triggered on steep slopes.
