WX AT DFW; TX; RESULTS IN AN ACR PLT USING HIS DISCRETION TO AVOID WX WHEN UNABLE TO GET CLRNC FOR WX AVOIDANCE.

Narrative

DEPARTING DFW WITH QUITE A BIT OF WX IN THE AREA. AFTER WAITING IN LINE FOR MORE THAN 1 HR; THINGS STARTED MOVING AGAIN. TWR ADVISED THAT WE WERE DEPARTING 20 MI IN TRAIL DUE TO ALL THE DEVS. WE TOOK THE RWY (RWY 18L) AND DIDN'T SEE ANYTHING PARTICULARLY HVY ALONG RWY HDG. IMMEDIATELY AFTER DEP; THE RADAR PAINTED AN AREA OF HVY RAIN APPROX 5 MI OFF THE DEP END. UPON CONTACTING DEP CTL; I HAD THE FO ASK THE CTLR FOR 30 DEGS TO THE R FOR WX. HE SAID 'UNABLE; FLY HDG 185 DEGS.' WE TOLD HIM WE REALLY NEEDED A R TURN FOR WX; AND AGAIN WE WERE DENIED. FINALLY; WE INFORMED THE CTLR THAT WE WERE IN FACT TURNING TO AVOID WX AND WOULD FLY ABOUT A 250 DEG HDG NOW. HE DID NOT RESPOND; SO AGAIN WE TOLD HIM THAT WE WERE FLYING A 250 DEG HDG; AND RECEIVED A COMMENT WE COULDN'T MAKE OUT. AFTER A COUPLE OF MINS; WE INFORMED THE CTLR THAT WE NOW NEEDED TO COME BACK TO A MORE SW HDG. HIS RESPONSE WAS 'NO ONE ELSE IS HAVING ANY PROBS WITH THE WX.' AT THIS POINT; I GOT ON THE RADIO AND TOLD HIM THAT I DIDN'T CARE WHAT ANYONE ELSE WAS DOING; THAT WE HAD MODERATE TO HVY RAIN AND LIGHTNING ON THE NOSE AND NEEDED THE TURN. IMMEDIATELY AFTER THAT; A NEW CTLR GOT ON THE FREQ AND ALL WAS NORMAL. THERE WASN'T ANY TFC ON THE TCASII. WE WERE 20 MI IN TRAIL AND THE FREQ WAS ALMOST DEAD OF OTHER TFC. THE FO AND I TALKED ABOUT IT DURING THE REST OF THE FLT; AND BOTH AGREED THAT WE WERE WITHIN MOMENTS OF DECLARING AN EMER.