Background
Prior to departure, the flight crew received a weather briefing that included a SIGMET indicating the chance of severe turbulence along the proposed route. In anticipation of potential weather hazards, the crew took precautionary measures before entering instrument meteorological conditions (IMC). They activated the 'Fasten Seat Belt' signs and issued verbal instructions for passengers to return to their seats and fasten their seat belts.
Incident
During the flight, the pilot-in-command observed precipitation on radar and diverted the airplane to avoid it. However, as the aircraft came into close proximity to the precipitation, it encountered what the crew described as three to four seconds of 'moderate' chop. The sudden turbulence affected individuals who were not properly secured.
Injuries
As a result of the encounter, an unseated passenger sustained minor injuries, and a flight attendant received serious injuries. The report does not specify the nature of the injuries or the total number of occupants on board.
No additional details about the aircraft, flight number, or operator were provided in the source material.