On February 13, 2025, Southwest Airlines flight 3338, operating from Metropolitan Oakland International Airport (OAK), Oakland, California, to San Diego International Airport (SAN), San Diego, California, encountered turbulence during descent. One flight attendant (FA) sustained a serious injury. Prior to departure, the flight crew reviewed weather data via the Weather Services International (WSI) and SkyPath applications and noted the possibility of turbulence during climb-out and descent. Flight attendants were briefed to remain seated until further notice. During climb and cruise, the aircraft experienced “light chop.” After the turbulence cleared, the flight crew permitted flight attendants to begin service. The seatbelt sign was subsequently turned off for passengers, and the remainder of the cruise segment was uneventful. According to the flight crew, they continued to monitor the weather and noted no “moderate turbulence plots” along the route, though they did observe occasional “light turbulence plots.” At FL300, prior to descent, the captain reactivated the seatbelt sign and advised passengers to be seated. Shortly thereafter, while descending through scattered clouds between FL300 and FL250, the airplane encountered moderate turbulence. The captain then instructed the FAs to take their seats. According to the FAs, although the flight crew had illuminated the seatbelt sign and briefed passengers via the PA about the impending turbulence, no separate advisory was provided to the cabin crew before the turbulence event. When the turbulence subsided, the flight crew checked on the FAs via the interphone and was informed that one FA had been seriously injured. The captain subsequently requested medical personnel and a manager to meet the flight upon arrival.