POTENTIAL CONFLICT DURING HDG TRACK WX DEV.

Narrative

ON CLBOUT FROM IAH; DEP ISSUED HDG OF 020 DEGS; AND AFTER ON THE HDG ASSIGNED; CREW DECIDED TO DEV TO THE N FOR WX AVOIDANCE AND MADE A CALL TO DEP; BUT WAS BLOCKED OR STEPPED ON BY OTHER XMISSIONS. SUBSEQUENTLY; THE DEP CTLR CALLED ASKING OUR HDG AND REASON FOR DEV AND THAT THERE WAS TFC AT OUR 12 O'CLOCK POS THAT COULD BE CONFLICTING WITH OUR FLT PATH AND GAVE US A HDG OF 090 DEGS TO AVOID THE POSSIBLE CONFLICT. AFTER TFC WAS NO FACTOR; WE RECEIVED A HDG OF 360 DEGS TO RESUME NAV TO JOIN THE AIRWAY. THEN AN EXPLANATION FROM THE CTLR AS TO THE EVENTS AND REASONS WE SHOULD NOT HAVE DEVIATED OFF COURSE UNTIL CLRED BY ATC. THE CREW FELT THE NECESSITY WAS IMPERATIVE FOR THE SAFETY OF THE CREW; PAX AND ACFT AND THAT WE WERE SURE THAT ATC COULD SEE THIS DEV AND PLAN ACCORDINGLY. COORD BTWN ATC AND ACFT IS OF THE HIGHEST CONCERN FOR THE SAFETY IN OUR AIRWAY SYS AND WE ARE THANKFUL THIS SYS WORKED TODAY. SUPPLEMENTAL INFO FROM ACN 272287: VERY HAZY DAY -- ON ASSIGNED TKOF HDG WE ENCOUNTERED A STRONG TWRING CUMULUS THAT WAS DIRECTLY IN OUR FLT PATH. WE HAD TO TAKE EVASIVE ACTION TO MISS IT; BUT WERE NOT ABLE TO ALERT CTLR BEFORE TURNING -- HE WAS TALKING TO ANOTHER ACFT AND WE COULD NOT GET IN ON FREQ. I CORRECTED BACK TO ASSIGNED HDG; AND CTLR INFORMED US WE HADN'T INFORMED HIM BEFORE TURNING AND THAT WE HAD HAD A POTENTIAL PROB WITH A HELI.