What happened
While operating at flight level 330, the crew of a Boeing aircraft (type not specified) performed a rightward deviation from their flight path to avoid a nearby thunderstorm rated at level 6 intensity. During this maneuver, the aircraft encountered moderate turbulence lasting approximately one second.
The turbulence resulted in one serious injury to a flight attendant. According to the captain's report, the seat belt sign was not illuminated at the time of the encounter.
Approximately two minutes following the event, the Jacksonville Air Route Traffic Control Center Weather Service Unit issued a center weather advisory. This advisory described a thunderstorm characterized by moderate rain with tops reaching flight level 450 and a diameter of 20 nautical miles. When plotted, the center of this storm was located roughly 23 nautical miles from the site of the accident.