Where is the warm sector of a mature extra tropical cyclone?

My question says: Thunderstorm cells that spawn intense tornadoes such as the Oklahoma City tornado typicaly are ociated with the warm sector of a mature xtra-tropical cyclone. Considering the circulation surrounding a low pressure system and the path of the Oklahoma City tornad, it is likely that its parent thunderstorm formed generaly to the (northwest) or (southeast) of the center of an extra tropical cyclone. But how do I figure this out? The tornado is moving Northeast, and I Think the circulation is counter clockwise, but I don't know where the warm sector is or how to figure out which side the parent thunderstorm was.