Powder reset in the St. Mary's

Recent storm gave the St Mary's a good reset with 30-40 cm of powder (except for a sun crust forming on south-facing slopes). We approached all steep terrain very cautiously as we were uncertain about both the storm snow and recently buried surface hoar layers. We had some whumpfs on a south-facing roll in a cutblock at 1800 m, but no other signs of instability or recent avalanches. Our whumpfs were on a 60 cm deep surface hoar layer. This layer was visible in a few pits but was only reactive at this location, suggesting the problem is isolated.