Narrative:

Captain's emergency authority/authorized used. Z time: XA07Z. Frequency/altitude: ZJX/FL310. ATC facility: ZJX. Location: cty/285 degree radial/42 DME. Line of thunderstorms from north of lal to cty and east. Deviated to west of line. ZJX an acmi extension, which is not shown on the us hi 5-6 chart 'according to jax' or warning area 470 and told me to turn right 15 degrees initially, and later told me to turn right 40 degrees. This would have put me squarely into the middle of both a severe thunderstorm, and the line of severe storms I was trying to avoid. In the interest of flight safety, I told jax I would need a left turn to approximately 275 degrees for thunderstorm avoidance. The controller told me to squawk 7700, and asked if I was exercising my emergency authority/authorized. I said if necessary, yes, and he initiated the emergency at XA07Z. I was on the cty 285 degree radial/42 DME. After circumventing the line of thunderstorms, I turned to 015 degrees as instructed, and eventually told to proceed direct to vhp, on a 355 degree heading. The emergency was terminated at XB24Z 5 mi southeast of pfn. Both my copilot and jump seat observer 'another pilot,' agreed with my decision.

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Original NASA ASRS Text

Title: ZJX CTLR INSTRUCTED ACFT DEVIATING AROUND A TSTM NEAR A MIL RESTR AREA TO SQUAWK 7700 EMER.

Narrative: CAPT'S EMER AUTH USED. Z TIME: XA07Z. FREQ/ALT: ZJX/FL310. ATC FACILITY: ZJX. LOCATION: CTY/285 DEG RADIAL/42 DME. LINE OF TSTMS FROM N OF LAL TO CTY AND E. DEVIATED TO W OF LINE. ZJX AN ACMI EXTENSION, WHICH IS NOT SHOWN ON THE US HI 5-6 CHART 'ACCORDING TO JAX' OR WARNING AREA 470 AND TOLD ME TO TURN R 15 DEGS INITIALLY, AND LATER TOLD ME TO TURN R 40 DEGS. THIS WOULD HAVE PUT ME SQUARELY INTO THE MIDDLE OF BOTH A SEVERE TSTM, AND THE LINE OF SEVERE STORMS I WAS TRYING TO AVOID. IN THE INTEREST OF FLT SAFETY, I TOLD JAX I WOULD NEED A L TURN TO APPROX 275 DEGS FOR TSTM AVOIDANCE. THE CTLR TOLD ME TO SQUAWK 7700, AND ASKED IF I WAS EXERCISING MY EMER AUTH. I SAID IF NECESSARY, YES, AND HE INITIATED THE EMER AT XA07Z. I WAS ON THE CTY 285 DEG RADIAL/42 DME. AFTER CIRCUMVENTING THE LINE OF TSTMS, I TURNED TO 015 DEGS AS INSTRUCTED, AND EVENTUALLY TOLD TO PROCEED DIRECT TO VHP, ON A 355 DEG HDG. THE EMER WAS TERMINATED AT XB24Z 5 MI SE OF PFN. BOTH MY COPLT AND JUMP SEAT OBSERVER 'ANOTHER PLT,' AGREED WITH MY DECISION.

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.