The Dispatcher and the Captain of an air carrier flight reported the flight's encounter with severe turbulence and the ultimate diversion to another airport.
Synopsis
The Dispatcher and the Captain of an air carrier flight reported the flight's encounter with severe turbulence and the ultimate diversion to another airport.
Narrative
There was a WSI SIGMET for Moderate Turbulence and wind shear across the ZZZ region. I do not recall seeing any significant PIREPs at that time. ZZZ Operations called to advise me that an inbound flight wanted a radio patch with me. In the background the flight was on the radio and said they were diverting to another airport due to severe turbulence inbound to ZZZ. I asked the agent to verify they were headed to ZZZ1 and I heard their reply that; yes; they had injuries in the cabin and they were diverting ZZZ1. ZZZ1 was an alternate on their release; so I did not amend the release; but called Chief Dispatcher and ensured appropriate support divisions were all notified. We then saw the flight crew's PIREP for severe turbulence over FIM at FL130. We had no other flights in or out of ZZZ for several hours. The flight crew paperwork had the WSI SIGMET for Moderate Turbulence and wind shear over the region. I was told there was also a NWS SIGMET in effect for that region that was forecasting possible severe turbulence. I did not see that SIGMET nor was it in the briefing packet for the flight. I do not know if the dispatcher that released the flight was aware of the NWS SIGMET. The Company computer program does not include NWS SIGMETs in the flight crew paperwork. It only includes WSI generated SIGMETs.
Second reporter narrative
I briefed the lead Flight Attendant and told her about the turbulence. I also informed her that I wanted all the Flight Attendants to be seated at top of descent and that I would inform her of the exact time once we had a better estimate. About 25 minutes before top of descent I call the A Flight Attendant and told her I wanted them seated at 31 past the hour; which was top of descent. We were about 5 miles north of ZZZ VOR when we encountered the first bout of severe turbulence. The airspeed fluctuated from +40 to -16 KTS from our 220 KT target; and about +/-10 degrees of pitch and +/-20 degrees of bank. I disconnected the autopilot and autothrottles and started a climb and directed the First Officer to get a higher altitude from ATC. It took what I thought was full aileron to control the bank and a fair bit of elevator to control the pitch. Using my Captain's emergency authority I started a slow climb not wanting to over control the aircraft or make sudden excursions with the throttles. The flight position was selected on the igniters. The severe turbulence lasted 100 seconds. We informed Approach we were in severe turbulence and climbing; reluctantly Approach gave us 13;000; but they kept badgering us to what our intentions were. All told we encountered three bouts of severe turbulence. In the middle of the turbulence events the Flight Attendants called the First Officer and stated the passengers were screaming and we had multiple injuries; also something was mentioned about a baby. They asked for permission to help the passengers (God bless them); but we told them to remain seated. Arriving at the gate we were met with a large contingent of EMS personal and aid vehicles. They surveyed all the passengers and administered aid to the injured passenger.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.