HSV AFD 
“
It's at this point in the forecast that things get interesting. As
with any case of potential winter weather across the Southeast, you
normally have the available moisture, or the unseasonably cold air, 
but rarely both at the same time to provide the much-requested 
winter wonderland for Christmas Eve. This case is no different, and
despite the ensembles highlighting inches and inches of snow 
occurring in the wake of the cold front, sounding analysis just 
doesn't support it. The greatest lift arrives as much of the best 
moisture has already vacated the area to the E, which lowers the 
snowfall amounts significantly in an event like this. 
Here's what I think will truly happen (which is hard to depict the
fine-resolution of such thinking in a gridded forecast): The bulk of
the rain will push E just as the coldest air arrives into the area 
from the NW. Maybe one "heavier" snow band will set up and ride 
along with what's left of the greatest lift in the wake of the front,
and then we'll get a dusting or less from that burst of snow. A bit
of a break is expected for a few hours that morning, and then as
another piece of energy rotates through the base of the trof aloft
across the OH and northern TN Valley, we'll see some snow showers 
across N AL/Southern Middle TN. This won't be enough to cause much 
in the way of additional accumulations, but for those of you (like 
me) who just like to see the snow fall from the sky, then this 
forecast is for you! Models hint at maybe a little more accumulation 
than a dusting in the higher terrain of NE Alabama and Southern 
Middle TN, but overall snowfall totals range from a few tenths in NW 
AL to perhaps 0.5-0.7" in higher terrain locations. There is still a 
little uncertainty with this event, despite being 24-36 hours out. 
Stay tuned as additional forecast updates are expected.”