Narrative:

We were being vectored for final approach. Our radar showed 2 cells developing side by side with our current track taking us between the two. We advised approach that we would like to deviate due to WX. They curtly advised us 'unable, turn right to 080 degree'. That heading would have placed us directly toward another contoured cell. The captain chose to turn left away from the WX. I advised ord of our intentions to which they promptly began a surely of other aircraft in our area who had already passed the build-ups as to the ride and WX through the line. Chicago reluctantly provided vectors around the area and back onto the arrival corridor. No conflict was created other than an upset controller when we refused to drive through a contoured cell. It is interesting to note that ATC never knows anything about the WX you're about to enter unless they want you in a particular place, then they seem to be experts. Perhaps in the current overstressed and understaffed ATC they have forgotten how fast WX can and does build!

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Original NASA ASRS Text

Title: FLT CREW OF LGT ON APCH TO ORD DEVIATED CONTRARY TO CTLR'S INSTRUCTIONS TO AVOID A CONTOURED TSTM CELL.

Narrative: WE WERE BEING VECTORED FOR FINAL APCH. OUR RADAR SHOWED 2 CELLS DEVELOPING SIDE BY SIDE WITH OUR CURRENT TRACK TAKING US BETWEEN THE TWO. WE ADVISED APCH THAT WE WOULD LIKE TO DEVIATE DUE TO WX. THEY CURTLY ADVISED US 'UNABLE, TURN RIGHT TO 080 DEG'. THAT HDG WOULD HAVE PLACED US DIRECTLY TOWARD ANOTHER CONTOURED CELL. THE CAPT CHOSE TO TURN LEFT AWAY FROM THE WX. I ADVISED ORD OF OUR INTENTIONS TO WHICH THEY PROMPTLY BEGAN A SURELY OF OTHER ACFT IN OUR AREA WHO HAD ALREADY PASSED THE BUILD-UPS AS TO THE RIDE AND WX THROUGH THE LINE. CHICAGO RELUCTANTLY PROVIDED VECTORS AROUND THE AREA AND BACK ONTO THE ARR CORRIDOR. NO CONFLICT WAS CREATED OTHER THAN AN UPSET CTLR WHEN WE REFUSED TO DRIVE THROUGH A CONTOURED CELL. IT IS INTERESTING TO NOTE THAT ATC NEVER KNOWS ANYTHING ABOUT THE WX YOU'RE ABOUT TO ENTER UNLESS THEY WANT YOU IN A PARTICULAR PLACE, THEN THEY SEEM TO BE EXPERTS. PERHAPS IN THE CURRENT OVERSTRESSED AND UNDERSTAFFED ATC THEY HAVE FORGOTTEN HOW FAST WX CAN AND DOES BUILD!

Data retrieved from NASA's ASRS site as of August 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.