At about 20:10 CDT, a passenger on Southwest Airlines Flight 1857 sustained a fractured wrist while jumping from the airplane after arrival at Nashville. The Boeing 737-500 was about one hour into a ramp hold due to a weather-induced airport power outage and subsequent gate unavailability. Prior to jumping from the airplane, the passenger repeatedly left his seat, approached a flight attendant at one of the aft entry doors and told her he needed some air. She directed him to reseat himself. On the third such encounter the passenger grabbed the flight attendants hair, opened the slightly ajar door and jumped to the tarmac. The flight attendant remained aboard the airplane and was not injured.