Date: 201406
Local time of day: 1201-1800
Location: A80.TRACON, GA
Flight conditions: VMC
Weather elements / visibility: Thunderstorm
Light: Daylight
Aircraft: Medium Transport; Low Wing; 2 Turbojet Eng
Operator: Fractional
Operating under: Part 91
Flight plan: IFR
Flight phase: Climb
Airspace: Class A ZTL
ATC / advisory: TRACON A80
Reporter organization: Corporate
Reporter function: Captain; Pilot Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Communication Breakdown; Distraction; Troubleshooting; Workload
Anomaly: ATC Issue All Types; Deviation - Track / Heading All Types; Inflight Event / Encounter Weather / Turbulence
Detector: Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Issued New Clearance; Flight Crew Requested ATC Assistance / Clarification; General Declared Emergency
Contributing factors: Weather
Primary problem: Weather

Narrative: We were getting staggered climb instructions from the low teens to low 20's in altitude. ATC wanted us to turn left to 240 heading. We did; but it looked bad on radar (red returns of two cells that seemed to be growing into each other) and visually (gray and black areas of clouds and virga) due to the thunderstorms we were getting vectored into. We requested a west; northwest; or south heading to avoid the weather. At some point in time it sounded as if an ATC observer/supervisor took over their side of the conversation. We were told we could not turn west or south and had to fly the assigned 240 heading (10 degrees left or right of that heading was approved as well). The Controller also mentioned that a Challenger aircraft had just gone through with only light to moderate turbulence. There appeared to be less than 3 miles between the 2 cells that they were trying to vector us through. Not liking what I saw on the radar; as well as visually; my concerns included thunderstorm penetration; the possibility of hail; lightning strikes; turbulence; heavy precipitation; potential inability to maintain altitude or speed; and company FOM thunderstorm separation criteria; among others. After a brief pause; to discuss with my co-pilot; and possibly some more back-and-forth with ATC (who remained unrelenting in their vector assignment); I (for at least the second time) informed the Controller that the assigned heading was no good. I continued by declaring a weather emergency and requested a turn to the north. ATC immediately gave us a turn to the northwest (which was acceptable) and we remained safely out of the thunderstorms. After a frequency change; a few good vectors; and much more helpful and understanding controllers; we continued to our planned destination without further incident. During the event; I do not recall seeing any potential traffic conflicts visually or on TCAS; nor were any pointed out to us by ATC. I have no idea why we couldn't get what we needed without declaring an emergency except that maybe a Controller/Supervisor was so used to moving traffic a certain way that doing something different wasn't even a consideration or possibility for them. I really don't know; but I do realize that ATL is the busiest airport in the world; so I'm sure there are ATC considerations and needs that I am unaware of. There was no specific acknowledgment of our weather emergency declaration; aside from the vector; and there were no further references to the event by the initial or any subsequent controllers (aside from normal weather concerns); although I did try to recognize and apologize for the inconvenience to subsequent controllers. We were VMC almost the entire time and did not penetrate any amber or red areas. Perhaps we had climbed above the weather by then. It was a somewhat stressful situation and my memory of more details fails me. After clearing all weather hazards and continuing on our way; we were told that FL340 would be our final (glad we had a little extra fuel as we were filed for FL400). ATC did ask if that was ok; and I replied in the affirmative; but that could have led to an additional event. I also contacted the on-duty Assistant Chief Pilot to advise of the event.I don't know where to start. Maybe just a better understanding between pilots and controllers as to what each needs; and perhaps better controller understanding of the unpredictability and rapid changes that can occur with thunderstorms. Just because someone else went through a hole 30 seconds ago; doesn't mean that I am safe or willing to do so.




Synopsis: Pilot reports of flight that is hampered by weather and he requests to deviate only to be told by the Controller that he cannot. Pilot declares weather emergency and is given a vector clear of thunderstorms.