Whumpf

2800m elev, north aspect 32 degree angle supported slope. Very large whumpf while making skin uptrack, multiple people on slope. Suspect facetted lower snowpack. No snow profiles, HST 100cm. Firm layer 25cm down. Ski pen 15 cm, foot pen 20cm, dry powder. No naturals throughout the day. Low visibility this day and S-1. Skiing felt good but couldn't see it.