That is impressive. As I previously mentioned years ago I was able to get KTRH groundwave in the New Orleans area. To think that it gets to the Florida panhandle by day is excellent.KTRH popping up there at any point daytime is pretty impressive. There is plenty of land between their towers northeast of Houston and your location, most notably in the first few hundred miles that signal would have to cross before it hits any salt water to speak of.
Nighttime reception doesn't surprise me. On my two visits to the Florida panhandle, it was there every time I checked at night. Never strong and I doubt that lobe would make it all that much farther east, but it was there.