FLC HAS TCASII TA WHILE AVOIDING TSTMS.

Narrative

FLT FROM BALTIMORE TO ATLANTA XX14 LIFTOFF FROM BWI. PRIOR TO DEP ROLL; RADAR ON; WE NOTICED A LINE OF WX 25 MI W. AFTER TKOF DURING OUR CLB TO 4000 FT SWITCHED TO BALTIMORE DEP. DEP CLRED US TO CLB TO 9000 FT. WE MADE REF TO THE WX AND INDICATED OUR DESIRE TO DEV SLIGHTLY S BY 10-15 DEGS FOR A S END RUN AROUND A LINE OF TSTMS. NO ANSWER CAME BACK. ABOUT 30 SECONDS LATER WE ASKED AGAIN FOR A SLIGHT TURN TO THE L FOR WX AND THE CTLR CAME BACK AND SAID 'UNABLE.' WE WERE NOW UNABLE TO TURN R BECAUSE OF A CELL VISIBLE JUST TO OUR R AND WE ASKED AGAIN FOR A SLIGHT L TURN. THE CTLR SAID UNABLE AND WANTED US TO TURN R TO 360 DEGS INTO THE CELL AND WE SAID THE ONLY WAY WE CAN GO IS L. THE CTLR FINALLY SAID 'TURN L WITH TFC AT 8000 FT (WE HAD LEVELED AT 7500 FT ON OUR OWN USING TCASII) AND FOR US TO SQUAWK 7700. WE DID ALL THAT AND ASKED FOR A DSCNT TO 7000 FT FOR CLRNC FROM OUR TFC WHICH WAS NOW A TCASII ALERT. WE AVOIDED THE WX AND THE ACFT USING EQUIP ON OUR ACFT WITH NO HELP FROM ATC. I FEEL ATC COULD HAVE STOPPED OUR CLB AT 5000 FT OR 700 FT FOR CLRNC FROM THE 8000 FT ACFT AND CLRED US FROM THE WX WITHOUT HAVING TO SQUAWK EMER 7700.