Narrative:

We departed ewr on a flight to elmira, ny. After leveling off at 12000', center cleared us directly to the elmira VOR. We starting painting thunderstorms on our radar and asked for 14000' to get above some intermediate clouds to allow a better view of the WX and also allow us to maneuver around some lower clouds. As we approached the thunderstorm vicinity and noticed the rapidly changing cloud activity to the right of the storm, we immediately began a deviation to the left. We entered some lower clouds as we attempted to get back into clear air. We were very surprised when we encountered severe turbulence. I was unable to hold our assigned altitude of 12000' due to extreme updrafts and the aircraft went from 12000 to 12700'. Center noticed our altitude deviation and asked us to immediately return to 12000' due to 13000' traffic in our vicinity. I immediately returned to 12000' and, shortly thereafter, we returned to VMC conditions. The problems involved in this situation were compounded by our inability to get a higher altitude when initially requested. A higher altitude would have allowed us to better interpret the WX situation and more effectively take evasive action. The intensity of the turbulence in the lower altitude clouds was expected. This altitude deviation could have been avoided by staying clear of all clouds in an intense frontal area, even those not directly associated with a thunderstorm cell. The intensity of the turbulence could be totally out of proportion with the size and height of the cloud.

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Original NASA ASRS Text

Title: INFLT ENCOUNTER WITH ENROUTE WX AND TSTM ACTIVITY CREATES AN ALT DEVIATION ALT EXCURSION.

Narrative: WE DEPARTED EWR ON A FLT TO ELMIRA, NY. AFTER LEVELING OFF AT 12000', CENTER CLRED US DIRECTLY TO THE ELMIRA VOR. WE STARTING PAINTING TSTMS ON OUR RADAR AND ASKED FOR 14000' TO GET ABOVE SOME INTERMEDIATE CLOUDS TO ALLOW A BETTER VIEW OF THE WX AND ALSO ALLOW US TO MANEUVER AROUND SOME LOWER CLOUDS. AS WE APCHED THE TSTM VICINITY AND NOTICED THE RAPIDLY CHANGING CLOUD ACTIVITY TO THE RIGHT OF THE STORM, WE IMMEDIATELY BEGAN A DEVIATION TO THE LEFT. WE ENTERED SOME LOWER CLOUDS AS WE ATTEMPTED TO GET BACK INTO CLR AIR. WE WERE VERY SURPRISED WHEN WE ENCOUNTERED SEVERE TURB. I WAS UNABLE TO HOLD OUR ASSIGNED ALT OF 12000' DUE TO EXTREME UPDRAFTS AND THE ACFT WENT FROM 12000 TO 12700'. CENTER NOTICED OUR ALT DEVIATION AND ASKED US TO IMMEDIATELY RETURN TO 12000' DUE TO 13000' TFC IN OUR VICINITY. I IMMEDIATELY RETURNED TO 12000' AND, SHORTLY THEREAFTER, WE RETURNED TO VMC CONDITIONS. THE PROBS INVOLVED IN THIS SITUATION WERE COMPOUNDED BY OUR INABILITY TO GET A HIGHER ALT WHEN INITIALLY REQUESTED. A HIGHER ALT WOULD HAVE ALLOWED US TO BETTER INTERPRET THE WX SITUATION AND MORE EFFECTIVELY TAKE EVASIVE ACTION. THE INTENSITY OF THE TURB IN THE LOWER ALT CLOUDS WAS EXPECTED. THIS ALT DEVIATION COULD HAVE BEEN AVOIDED BY STAYING CLR OF ALL CLOUDS IN AN INTENSE FRONTAL AREA, EVEN THOSE NOT DIRECTLY ASSOCIATED WITH A TSTM CELL. THE INTENSITY OF THE TURB COULD BE TOTALLY OUT OF PROPORTION WITH THE SIZE AND HEIGHT OF THE CLOUD.

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.