A look at the 3/21 avalanche in NE bowl of Powderhouse Peak.

We received a report of a skier triggered avalanche occurring at 6:15 pm on 3/21 with minimal details so we went to investigate. We found the fresh crown, flanks, and debris of a deep slab avalanche that was less than 24 hours old in the area as reported. Due to the location of the avalanche within the steep terrain and possible lingering hazard we were unable to access the crown or flanks directly. Another deep slab avalanche was human triggered here on 3/15. Some remnants of the old crown from that avalanche were almost entirely filled in but still visible in a few areas.

We dug a snowpit adjacent to the climber's left flank of the 3/21 avalanche and were unable to reproduce this deep slab failure in snowpit tests. It is unclear if this avalanche failed on old facets just below the old snow/storm snow interface or on a graupel layer at the old snow/storm snow interface.

Otherwise, we encountered the expected well settled storm snow with no additional obvious signs of instability. SE aspect slopes were experiencing minor warming and surface wet snow formation while steeper N aspects were escaping evidence of snow surface warming.

Upon our departure from the area around 1:30 pm, thick convective cloud cover was moving overhead with light snow showers visible in the distance.