A survey of Limestone County after Wednesday’s storms revealed signs of a gustnado in the area, not a tornado, according to the National Weather Service.

Gustnadoes are small whirlwinds that form along the edges of thunderstorms and do not connect with cloud-based rotation, making them different from tornadoes. The NWS classifies them as “thunderstorm wind events” but notes they can be strong enough to cause damage.

NWS had issued a tornado warning Wednesday night after possible tornadoes were reported in North Alabama, with one headed from Rogersville toward Athens. On Friday, NWS released a public information statement in which they said a preliminary review of eyewitness statements, video evidence and “very little” damage in the area made it more likely that a gustnado was involved.

“A possible gustnado developed on the leading edge of a thunderstorm cluster and moved through along (U.S.) 31, north of Tanner,” NWS officials said in the statement. “Very minor damage was observed in this area and winds were estimated to be below 60 mph.”

NWS thanked Limestone County Emergency Management Agency for its help in surveying the area.