Regarding Erin, yes, it is unusual but not necessarily unprecedented. Most of the other cases involve interaction with a trough and occur much further to the east, though there are a few Texas cases as well. What happened last night was probably somewhat similar to intense convective systems that fire in the central Plains during the warm season, with an intense low level jet stream supporting convection on the east side of the storm. The remnant circulation center provided the focusing mechanism for that convection and it took on the appearance of an intense overland tropical cyclone once again.