Narrative:

At cruise at 31000 ft, we were in IMC and circumventing many radar echoes for the prior 15 mins. We were just about to exit the WX area when we hit moderate to severe turbulence for 10 seconds. Our altitude went up to 31500 ft before the first officer was able to ease it over gently to stop the ascent. It evidently wasn't gentle enough in the back of the airplane, as 1 flight attendant hit the ceiling. Beverage service was spilled all over the cabin floor. 1 other flight attendant jammed her knuckle. 2 passenger had minor bumps. The first officer was flying the airplane between 2 large radar echoes, perhaps 30 mi apart, and doing a good job keeping us in smooth air. I noticed 2 or 3 very small echoes in our path, maybe 1 mi in diameter, but I was more concerned with the large echoes to our left and right, so I allowed the first officer to continue. I was just about to release the seat belt sign when we hit the turbulence. In retrospect, the only difference between these and previous, benign echoes we had gone nearby, was this later one had defined edges, and the prior ones had diffuse edges.

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Original NASA ASRS Text

Title: INFLT ENCOUNTER WITH TURB IN PROX OF TSTM ACTIVITY. CABIN ATTENDANT PAX INJURY.

Narrative: AT CRUISE AT 31000 FT, WE WERE IN IMC AND CIRCUMVENTING MANY RADAR ECHOES FOR THE PRIOR 15 MINS. WE WERE JUST ABOUT TO EXIT THE WX AREA WHEN WE HIT MODERATE TO SEVERE TURB FOR 10 SECONDS. OUR ALT WENT UP TO 31500 FT BEFORE THE FO WAS ABLE TO EASE IT OVER GENTLY TO STOP THE ASCENT. IT EVIDENTLY WASN'T GENTLE ENOUGH IN THE BACK OF THE AIRPLANE, AS 1 FLT ATTENDANT HIT THE CEILING. BEVERAGE SVC WAS SPILLED ALL OVER THE CABIN FLOOR. 1 OTHER FLT ATTENDANT JAMMED HER KNUCKLE. 2 PAX HAD MINOR BUMPS. THE FO WAS FLYING THE AIRPLANE BTWN 2 LARGE RADAR ECHOES, PERHAPS 30 MI APART, AND DOING A GOOD JOB KEEPING US IN SMOOTH AIR. I NOTICED 2 OR 3 VERY SMALL ECHOES IN OUR PATH, MAYBE 1 MI IN DIAMETER, BUT I WAS MORE CONCERNED WITH THE LARGE ECHOES TO OUR L AND R, SO I ALLOWED THE FO TO CONTINUE. I WAS JUST ABOUT TO RELEASE THE SEAT BELT SIGN WHEN WE HIT THE TURB. IN RETROSPECT, THE ONLY DIFFERENCE BTWN THESE AND PREVIOUS, BENIGN ECHOES WE HAD GONE NEARBY, WAS THIS LATER ONE HAD DEFINED EDGES, AND THE PRIOR ONES HAD DIFFUSE EDGES.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.