Avalanche: Superior

JPTD

Salt Lake » Little Cottonwood Canyon » Superior

South Ridge Superior - Dead Tree Chute

10,300'

Southeast

Natural

Unknown

Unknown

Our group headed up to ski Superior late this morning, starting around 9:00, expecting mostly cloudy skies. To our surprise, the sun was stronger than anticipated, and a thin cloud layer created a greenhouse effect that quickly warmed the snow. As we approached Little Superior, we began discussing whether we were already too late in the day for safe conditions. Deciding to continue, we stayed alert for any signs of instability. While I was leading, I heard what I initially hoped was just a thermal cycle moving up the mountain. But when I looked toward the cliffs above Dead Tree Chute (lookers’ right of the more commonly skied Country Lane), I saw a point-release wet loose slide breaking free. The avalanche accelerated quickly, gaining both volume and speed as it flowed over the cliffs. It split into multiple fingers, some flowing into the bottom of Country Lane, the rest into the gully on the skier’s left. The slide grew as it descended the mountain — clearly strong enough to knock a skier off their feet, and likely to cause serious injury. The toe of the debris came to rest roughly 40 meters below the final choke leading to the main Superior apron. Our group regrouped and decided the mountain was sending a clear message. The aspects that released are very similar to the south face we had planned to ski next, and we didn’t want to be caught under potential hangfire. We enjoyed a fun boot-ski on the ridgeline back to Little Superior and then skied down the LS ridge. Small, slow-moving wet snow releases occurred along the way, but we maintained safe terrain choices down. It was clear we would not have wanted to be there any later. I traversed over to the debris and ran a quick beacon search. Fortunately, nothing. We notified a group of 3 touring up the apron of what we had witnessed. The slide occurred around 11:50a. In short: more sun than expected, rapidly rising temperatures, and unusually warm snow made today’s conditions dangerous. The Wasatch is behaving differently than typical late February / early March patterns, and caution is essential on sun-exposed slopes during warming periods.