"Smoky Mountain rain, it keeps on fallin'." -Ronnie Milsap's "Smoky Mountain Rain"
"The name "Smoky" comes from the natural fog that often hangs over the range and presents as large smoke plumes from a distance. This fog, which is most common in the morning and after rainfall, is the result of warm humid air from the Gulf of Mexico cooling rapidly in the higher elevations of Southern Appalachia." -Wikipedia