BTW does'nt the speed limit drop down once you enter Virginia? I know for years it seemed like it did but it's been about 3 years since I went up through there.
The speed limit drops from 70 to 65 as you cross into Bristol VA; since Bristol TN is in Sullivan County, the whole thing is rather stupid, and with the hills, 65 mph is pretty solid speed (this ain't central Kansas topography here). As for gulf stream air, yes, part of the joy of the weather here is that it does benfit from stuff being brought from the Alabama/Louisiana region and bouncing up the Smokies 'draft pipe' to the area.