On October 26, 2023, a United Airlines flight UA194 experienced convective turbulence during a climb through 19,000 feet after departing San Francisco International Airport (SFO). The flight crew immediately declared an emergency and diverted to Denver, Colorado for medical assistance. Before departure, the lead flight attendant was instructed to remain seated until the 10,000-foot signal due to weather conditions at the departure airport. Approximately 12,000 feet above cloud level, the captain gave the 10,000-foot signal, instructing the flight attendants to begin initial service. During the climb, the flight encountered intermittent turbulence, with a smooth ride occurring once the airplane was above a cloud layer. Approximately 12,000 feet in, the captain issued the 10,000-foot signal, instructing the flight attendants to climb to FL350. Subsequently, as the airplane climbed through 19,000 feet, the flight crew encountered unexpected turbulence for approximately 5 seconds. The flight attendant experienced a violent and abrupt jolt, resulting in a fractured leg. Airmen’s Meteorological Information (AIRMETs) were in effect, indicating moderate turbulence below 12,000 feet and moderate turbulence from FL220 to FL360. A convective Significant Meteorological Information (SIGMET) was issued at 1455 PDT, indicating severe or greater turbulence, severe icing, and low-level windshear, and was in effect for the area with forecast thunderstorms. Numerous pilot reports (PIREPs) reported moderate or greater turbulence across central California, including the accident area, within two hours of the incident. The probable cause was an encounter with forecast convective turbulence during the climb.On October 26, 2023, a United Airlines flight UA194 experienced convective turbulence during a climb through 19,000 feet after departing San Francisco International Airport (SFO). The flight crew immediately declared an emergency and diverted to Denver, Colorado for medical assistance. Before departure, the lead flight attendant was instructed to remain seated until the 10,000-foot signal due to weather conditions at the departure airport. Approximately 12,000 feet above cloud level, the captain gave the 10,000-foot signal, instructing the flight attendants to begin initial service. During the climb, the flight encountered intermittent turbulence, with a smooth ride occurring once the airplane was above a cloud layer. Approximately 12,000 feet in, the captain issued the 10,000-foot signal, instructing the flight attendants to climb to FL350. Subsequently, as the airplane climbed through 19,000 feet, the flight crew encountered unexpected turbulence for approximately 5 seconds. The flight attendant experienced a violent and abrupt jolt, resulting in a fractured leg. Airmen’s Meteorological Information (AIRMETs) were in effect, indicating moderate turbulence below 12,000 feet and moderate turbulence from FL220 to FL360. A convective Significant Meteorological Information (SIGMET) was issued at 1455 PDT, indicating severe or greater turbulence, severe icing, and low-level windshear, and was in effect for the area with forecast thunderstorms. Numerous pilot reports (PIREPs) reported moderate or greater turbulence across central California, including the accident area, within two hours of the incident. The probable cause was an encounter with forecast convective turbulence during the climb.