A B737 ENCOUNTERS SEVERE TURB RESULTING IN A CABIN ATTENDANT INJURY.

Narrative

IN LEVEL CRUISE FLT AT FL390 APPROX 20 MI S OF ATL VOR; WE WERE DEVIATING TO THE W OF A CELL THAT WAS ABOVE OUR ALT. THE WIND AT ALT WAS 220 DEGS AT 35 KTS. THERE WERE SEVERAL SMALLER CELLS WELL BELOW US AND THEN; ALL OF A SUDDEN; THE RADAR PAINTED A RED CELL APPROX 1 MI WIDE AND 1 MI IN FRONT OF US. IT HAD TO BE CLBING VERY FAST! WE THEN SKIPPED OVER THE TOP OF THAT CELL AND THE ACFT CLBED TO APPROX FL394 AND THE STICK SHAKER SOUNDED MOMENTARILY AS MY FO REACHED FOR THE START SWITCHES THEN DSNDED TO FL386. THIS ALL TOOK PLACE IN ABOUT 10-15 SECONDS. AFTERWARDS FO SAID THAT WE HAD LOST 45-50 KTS OF AIRSPD. WE HAD 33 PAX ON BOARD. THE FLT ATTENDANT X CALLED AND SAID THE FLT ATTENDANT Y WAS IN THE AFT GALLEY AND A SPRITE CAN HAD HIT HER ON THE HEAD AND SHE BOUNCED AROUND THE AFT GALLEY. SHE THEN FELL TO THE FLOOR AND LANDED ON HER TAILBONE. FLT ATTENDANT X CALLED BACK AND SAID THAT FLT ATTENDANT Y WAS REQUESTING EMS CARE AND WOULD ALSO NEED TO BE PULLED FROM HER TRIP. WE USED ACARS AND ARRANGED IT WITH DISPATCH. FLT ATTENDANT Y WALKED OFF THE ACFT AND WENT TO THE DOCTOR ON HER OWN. ENRTE FO AND I DISCUSSED THE TURB AND DECIDED IT WAS MOMENTARILY SEVERE ACCORDING TO THE AIM. WE MADE A LOGBOOK ENTRY AND MAINT DID AN INSPECTION AND FOUND NO DAMAGE.