Hurricane #Ian is starting to undergo extratropical transition tonight on its way to the Carolinas. Notice the big dry slot sneaking in from the SW and frontal boundary extending from #Ian's south into the Bahamas... Fwiw, one of the simplest methods I use to discern b/t tropical & extratropical cyclones is to locate the subtropical jet & assume everything poleward/north of that is extratropical, while to the south = tropical. #Ian is in the middle rn => "hybrid" warm core/subtropical cyclone