The video showed a 4-mile-wide funnel cloud blanketing the skyline of a Southern California valley.
“Is this a tornado?” Steve Naglic, a meteorologist at the National Weather Service’s headquarters in West Columbia, S.C., asked 25 Richmond County firefighters, paramedics, sheriff’s deputies and emergency responders during a disaster training course this week at Georgia Regents University.
“No,” an emergency official shouted from the back of the classroom. “There’s no cloud rotation.”
At the beginning of the 90-minute class, Naglic’s question likely would have stumped each person in attendance. The severe-weather warning coordinator receives dozens of reports each year from residents in the Augusta area who are convinced a tornado is hovering over their homes, ready to strike.
The storm system on the screen was merely a “scud cloud,” a low, detached wind-torn storm fragment that does not produce severe weather.
“That is probably the best-looking fake tornado you will ever see,” Naglic said to the audience, his laser pointer fixed on the cloud footage. “Hollywood could not even make it better than this.”
Under Naglic’s guidance, 25 more emergency officials can now properly spot a tornado. The trick, Naglic said, is first watching a funnel cloud for 20 to 40 seconds to see whether it rotates. The next step is determining whether the cloud system is preceded by rain.
“Even the best-looking funnel clouds may not be a tornado,” Naglic said.
The meteorologist said 85 percent of tornadoes develop on the backside of a supercell thunderstorm system after rain currents have passed. The dead giveaway, Naglic said, is the “wall cloud,” a 1- to 4-mile-wide, rain-free base that lowers abruptly and is usually situated in the southwest portion of a tornado.
“Wall clouds are found in the rear of the storm; never on the leading edge,” Naglic said. “Sometimes they can have a noticeable tail, but they almost always follow rain or hail.”
Though peak tornado season has passed, Augusta has entered the critical stages of its hurricane and downburst periods. The two severe weather threats are known to produce 100-mph, water-balloonlike wind systems capable of flattening trees and causing flash flooding.
Mie Lucas, the disaster preparedness coordinator for Augusta’s Fire and Emergency Management Division, said she was pleased to see a full class and, based on community interest, plans to hold another severe-weather-spotting course in August.
“We know it is not tornado season, but hurricanes spawn tornadoes, and it is important that we are prepared,” Lucas said.
Naglic said most thunderstorms occur in the Southeast because it has the moisture, heat and atmospheric lift ripe for production. For tornado warnings to be issued, Naglic said, at least 58 mph winds and 1-inch hail must exist.
Pamela Nestor and Mary Keegan, of the Richmond County Community Emergency Response Team, said Naglic’s presentation was thorough, practical and extremely helpful.
“I learned a lot of things I did not know,” Nestor said. “One thing is for sure: I know I will be much more aware that tornadoes follow the rain.”