I will not add much to what Jimmy has already said about this event except that i was too late for the first supercell near Appin due to family commitments but I was able to get to south western Campbelltown in time to witness the new second supercell develop and chase it all the way to Heathcote Road and intercept it Menai. I then backed off away from the rain/hail core to Holsworthy and watched this storm until it started to collapse. I then headed back down to Appin, met up with Jimmy and watched an amazing supercell on sunset which developed over the mountains to our west.
Nice pics; this is what it looked like from the south end of Lake George at sunset: https://www.facebook.com/photo.php?fbid=739561486075076&set=gm.279871685507411&type=1&theater
Jeff Brislane, interesting motion being anticyclonic! So was this the anticyclonic couplet? I think there usually is an RFD (Rear flank downdraft) cutting in somewhere which I may have observed. This storm was very interesting to watch as well as confusing as this particular cell developed on the outflow of the original supercell!