The pilot of the tailwheel-equipped airplane reported that, the intention of the flight was to fly over a friend’s property to determine how much snow had accumulated. On a low approach without intent to land, the overcast sky and flat light made it difficult to determine his height above the field, and the airplane’s right wheel touched the soft snow and dug in. The pilot attempted a go-around, however the left main tire then dug in. He decided to land rather than lose directional control, however on rollout the airplane struck a snow drift that he could not see, and the airplane nosed over. The airplane sustained substantial damage to the left wing, vertical fin, and rudder. The pilot reported that there were no preaccident mechanical malfunctions or failures with the airplane that would have precluded normal operation.