Observation: Cardiff/Mineral

Route today was Cardiff Pass into Cardiff Fork to look at the avalanche occurrence from Sunday (observation). We ascended Cardiac Ridge when the southeast aspects were beginning to warm by about 10:30 am, dropping into north-facing Room of Doom, and exiting through Mineral Fork. Snow was much more stable than Sunday, with only minor sluffing in the storm snow on dry, northerly aspects. The density inversion was also much less apparent than on Sunday, and has quickly gained strength.

There were both natural and human-triggered avalanches in Cardiff Fork/Cardiac Bowl from Sunday, but Mineral Fork had much more natural activity, with numerous slides running over 1000'. The crowns all looked rather shallow (less than 30 cms), but the slabs were connected and the slides had propagated very widely, several hundred feet in some places. We were unable to identify graupel as a weak layer where we had dug around in Cardiff and Mineral, and the weaknesses from the Sunday avalanche cycle appeared to be a layer of low-density snow underneath a denser slab. This low-density layer was 15-20 cms deep, and the denser slab likely formed from heating and possibly some wind. What had surprised us was how shallow, yet connected, the storm slabs were.

Video and photos of the extensive avalanche activity in Mineral Fork.

Hazard was Low/Moderate in the morning on all aspects, most likely rising to Considerable on solar aspects by late morning. Mid and upper elevation north aspects remained Low/Moderate through the early afternoon when we had exited the canyon.

Southeast aspects began to warm by about 10:30 with rollerballs and loose, wet sluffs. Mid and upper elevation north aspects retained dry snow when we were exiting at 12:30 pm.