Date: 201511
Local time of day: 1201-1800
Location: ZZZ.Airport, US
Flight conditions: Mixed
Weather elements / visibility: Turbulence
Light: Daylight
Aircraft: A319
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Cruise
Airspace: Class A ZZZ
ATC / advisory: Center ZZZ
Reporter organization: Air Carrier
Reporter function: Pilot Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Second reporter function: Pilot Not Flying
Anomaly: Deviation - Altitude Excursion From Assigned Altitude; Flight Deck / Cabin / Aircraft Event Illness / Injury; Inflight Event / Encounter Weather / Turbulence
Detector: Person Flight Crew
When detected: In-flight
Result: General Physical Injury / Incapacitation
Contributing factors: Weather
Primary problem: Weather

Narrative: This report is in reference to a severe turbulence encounter. We flew down from our destination earlier and were cognizant of the convective activity around the area. We decided to hold west of the field and analyze the movement of the weather which was between us and the runway extending north to south for twenty miles. Other aircraft followed us into the hold.We saw a break in the line to the south of the field and flew until we could turn to the final approach fix and executed the RNAV approach. We picked up the field at 1;400 MSL and landed without incident. The weather worsened while at the gate with heavy rain and strong winds. I spoke with our Dispatcher on a plan for departure. He suggested FL280 for a better ride. We previously flew down at FL 390 and it was continuous light with some moderate turbulence.At taxi out; we decided to hold short of the departure runway and wait for the storms to move through. After considerable improvement in the weather we taxied on to the runway and made a radar sweep. The departure corridor looked excellent. We departed and climbed to FL 280. We requested a westerly deviation and were eight miles from our original track. We were well clear of any cells. I turned back on course after analyzing the radar. Out of nowhere we hit an area of severe turbulence which lasted for 3-5 seconds.The autopilot remained engaged and altitude varied plus or minus 200 feet. I immediately made a PA announcement for the Flight Attendants (FAs) to take their seats. I was informed by our Purser that she was thrown to the floor and the B FA was on the aft galley floor unable to get up. I told her to see if a Doctor was on board to help. Fortunately there was. I then reassured our customers that this was an isolated occurrence and to remain seated for the remainder of the flight.We conducted an HF phone patch with Dispatch to discuss the event that transpired. After receiving the B FAs vitals and condition; it was decided to continue to the destination. The physician had our FA stabilized in the last row. The flight continued and landed where medical personnel met our aircraft and transported our B FA to the hospital. The A FA had a lot of back pain but stayed on the trip. Our C FA also had back pain and got off the trip the following day. During deplaning a passenger told me she injured her thumb and ear during the turbulence and wanted medical evaluation. However; one of our crew members talked to her after we left the sterile period and she showed her the black and blue thumb before the incident happened. Also; she claimed to have hurt her left ear on the cabin sidewall but was seated in seat 14F. It would have been her right ear.Turbulence is a serious issue and this incident is a call to be even more cautious and vigilant in all phases of flight.


Second narrative: [Report Narrative Contained No Additional Information.]


Synopsis: An Aircraft encountered severe turbulence in the vicinity of convective weather activity. The event resulted in flight attendant injuries.