Cascadilla

We went to Casacadilla to take a closer look at a large avalanche on Nyack Mountain reported by the BSNF Snow Safety team. 

• We had a brief window of visibility in the morning that confirmed that a recent large avalanche failed on the northeast face of Nyack Mountain.
• A 2.5-inch rain crust made travel slow. The crust was breaking under our skis until 4700 feet. Above this elevation, the crust was increasingly supportable but also slick. Skinning with a few inches of low-density snow on this knife-hard crust was also slow.
• There was widespread evidence that low and mid-elevations in this drainage were impacted by rain. We estimate this rain occurred on February 25th.
• With the rain,  many of the steep chutes in Cascadilla had wet loose debris. Some wet loose debris appeared to trigger thin slabs at low elevations.
• Well-developed runnels that have since frozen added to a challenging surface for skiing.
• Light snowfall on and off throughout the day accumulated 2 inches of low-density snow. We experienced harmless sluff on some steep slopes.

• Two inches of low-density snow, including graupel, fell during our tour.
• A 2.5-inch rain crust underlying the new snow was increasingly supportable and slick, as we gained elevation.
• The new snow readily sluffed on the recent rain crust. It was harmless and easily managed.
• Total snow depths at middle elevations range from 180 to 200 cm.