ACFT RISES 1200 FT AS IT ENTERS CONVECTIVE LIFTING AREA.

Narrative

ON JUL/XX/94 COMING FROM MLB TO AHN I WAS AROUND 10000 FT N OF JAX WHEN I ENCOUNTERED CONVECTED ACTIVITY WHICH WAS AN UPDRAFT AT GREATER THAN 2000 FPM. I IMMEDIATELY NOTIFIED CTR BUT FOR SOME REASON CTR DID NOT UNDERSTAND WHEN I INFORMED CTR ABOUT CONVECTED ACTIVITY WHICH HAD CAUSED ME TO CLB 1200 FT WITHIN ABOUT 20 SECONDS. I WAS FLYING A CESSNA ON EACH OF THE OCCASIONS REFERRED TO ABOVE. IN THE ALT EXCURSION I WAS IN WHAT WAS BASICALLY AN EMER SIT BECAUSE OF THE CONVECTIVE AND DID MY BEST TO SIMPLY KEEP THE WINGS LEVEL AND CTL THE AIRPLANE FOR THE 20 SECONDS THE ALT WAS INCREASING IN TURB AND NOTIFIED CTR IMMEDIATELY. IT WAS SIMPLY IMPOSSIBLE TO MAINTAIN ALT IN THE FACE OF AN AIR MASS WHICH WAS RISING IN EXCESS OF 2000 FPM (MY VERT SPD INDICATOR PEGGED AT 2000 FT) AND I DID NOTIFY CTR IMMEDIATELY UPON GETTING THE AIRPLANE STABILIZED. IN FACT I NOTIFIED CTR WHILE WE WERE STILL IN THE RISING AIR MASS. WE WERE IN IMC ON AN IFR FLT PLAN. I HESITATE TO TALK BACK TO THE CTLRS BECAUSE WHEN THEY ADMONISH ME I FEEL IT WOULD SIMPLY WASTE AIR TIME FOR ME TO BE RESPONDING. I THINK THAT FROM NOW ON I WILL RESPOND.