There is a 50% - 80% chance of a tornado occurring in the high risk area ranging from South-Central Georgia into the Calhoun County area of SC. These storms can produce EF2-EF5 tornados.
To understand these designations here are the definitions for each EF Category as listed on NOOA.GOV
The Fujita Tornado Intensity Scale
Category F0: Gale tornado (40-72 mph); light damage. Some damage to chimneys; break branches off trees; push over shallow-rooted trees; damage to sign boards.
Category F1: Moderate tornado (73-112 mph); moderate damage. The lower limit is the beginning of hurricane wind speed; peel surface off roofs; mobile homes pushed off foundations or overturned; moving autos pushed off the roads.
Category F2: Significant tornado (113-157 mph); considerable damage. roofs torn off frame houses; mobile homes demolished; boxcars pushed over; large trees snapped or uprooted; light-object missiles generated.
Category F3: Severe tornado (158-206 mph); Severe damage. Roofs and some walls torn off well-constructed houses; trains overturned; most trees in forest uprooted; heavy cars lifted off ground and thrown.
Category F4: Devastating tornado (207-260 mph); Devastating damage. Well-constructed houses leveled; structure with weak foundation blown off some distance; cars thrown and large missiles generated.
Category F5: Incredible tornado (261-318 mph); Incredible damage. Strong frame houses lifted off foundations and carried considerable distance to disintegrate; automobile sized missiles fly through the air in excess of 100 yards; trees debarked; incredible phenomena will occur.
The alerts that are issued to the public concerning tornados are:
Tornado Watch is issued when conditions are favorable for a severe thunderstorm, called a Supercell, that can produce a tornado or even several tornados.
Tornado Warning is issued to warn the public that severe thunderstorms with tornados are imminent or occurring.
Calhoun County is under a Tornado Watch until 8p.m.