Hammy, I agree in that this was a case yesterday morning in which the models underestimated the strength of the dynamics, which were in play with this shortwave as it traversed through the TN Valley and eventually through the NC Mountains and Western NC Piedmont.
There was an impressive jet streak, which developed from the southwest yesterday that really energized the shortwave after it emerged from the Ozarks and into the TN Valley yesterday. Therefore, this bought about the robust snow totals by surprise. Also, the models had also a tendency in past runs the move the cold air out too quickly. As it turned out, there was quite a sufficient deep cold air pocket which stayed in place throughout areas, especially across Southeast TN and Northwest GA and Northeast Georgia Mountains right into early afternoon when the shortwave exited the region.
There were reports of areas receiving 6-8 inches in the extreme Northeast Georgia mountains. Impressive! They also had upwards to about an inch of snow in Clemson, SC and Greenville SC area and a dusting to 1/2 inch over in the Charlotte metro. Atlanta metro had some flurries, but for the most.part, the main action was just to their north and northeast, where the deepest cold pocket of air was situated.
So, Mother Nature indeed gave the Deep South a very unique suprise winter storm yesterday, so the 2019-2020 winter precip season turned out to have something to write home about after all for folks in Southeast TN, Northern GA and across into Upstate SC.