The pilot reported that, during the landing flare, it felt like "[something] pushed [the airplane] real hard from behind." He added that he applied power, but the airplane continued in a rapid descent. The airplane landed hard, bounced, and veered to the left upon the second touchdown. The pilot added full power and right rudder to recover, but the airplane exited the runway to the left and impacted a small hill. The airplane sustained substantial damage to the left wing. The pilot reported that there were no preaccident mechanical failures or malfunctions with the airplane that would have precluded normal operation. A review of recorded data from the automated weather observation station located on the airport reported that, about the time of the accident, the wind was from 310° at 12 knots, gusting to 19 knots. The airplane landed on runway 25.