An outbreak of tornadoes that tore across Alabama, Florida and Georgia on Sunday was among the deadliest in recent years, but the weather itself, supercell storms with the potential to produce intense tornadoes, is standard activity during springtime in the Southeast.
“Unfortunately, this is not unusual in the sense that this time of year the Southeastern U.S. is the most likely part of the country to experience tornadoes,” said Bill Bunting, operations branch chief with the National Oceanic and Atmospheric Administration’s (NOAA) Storm Prediction Center.
A tornado outbreak generally describes multiple tornado-producing storms that are more than 20 miles in length, said Bunting. They are typically associated with higher casualties because of the number of storms and the distance they cover. Weather officials said on Monday it would take a few days to determine exactly how many tornadoes were part of this outbreak.
On Monday afternoon, the National Weather Service’s Birmingham field office said the storm that devastated Alabama’s Lee County, which borders Georgia, was an EF4 tornado with winds estimated at 170 mph. It was the type of storm with the greatest potential for extreme damage depending on where it hits. More than 85 percent of tornado deaths occur in tornadoes that are EF3 or stronger, according to the NOAA.
Sunday’s tornadoes began as a classic severe weather setup, said Brad Nitz, meteorologist for Channel 2 Action News. “We had an approaching cold front, and ahead of that, we had a lot of moisture feeding the thunderstorm and vertical wind shear, which is a change in speed and direction of the wind,” he said.
The strong winds blowing from different directions at different levels of the atmosphere helped initiate and enhance the rotations of the supercell storms. “Those ingredients, the greater instability and strongest wind shear was just south of metro Atlanta down into Middle and South Georgia,” said Nitz. “That is why they got the tornadoes and we got more run-of-the-mill thunderstorms.”
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While no fatalities have been reported in Georgia as a result of the tornadoes, the reported death toll of at least 23 in Alabama is significant compared to 2018, when the total number of tornado fatalities nationwide for the year was 10.
A similar tornado outbreak in the Southeastern U.S. resulted in about 15 deaths in late January 2017, said Kyle Brehe, regional climatologist for the Southern Regional Climate Center at Louisiana State University in Baton Rouge. But April 2011 remains the deadliest tornado month on record across Alabama (245 deaths) and Georgia (16 deaths), according to NOAA data.
One of the greatest challenges with the tornadoes was their speed. “These storms were moving incredibly fast yesterday (Sunday), more than a mile a minute. It emphasizes the point of not waiting until you see the approaching storm to take action,” Bunting said.
In this case, meteorologists were able to anticipate the storm days in advance. The storms were clear and easy to see on the radar once they formed, Nitz said. The fact that the storm traveled over 100 miles was helpful in forecasting the possibility of tornadoes. “The storm that produced the tornado in Lee County was the same storm that produced a tornado in counties in Georgia. As the storm continued to show signs of tornado potential, the warning was reissued again farther downstream several times,” Nitz said.
While metro Atlanta was not directly impacted this time, Nitz said we can take an important lesson from the event. “As we look at this damage and try to help our neighbors to the south, it is a good time for all of us to reflect on what we would do if a tornado was threatening our location,” he said. “It is a good reminder to make sure you have a way of getting warnings in a timely manner and that you know the safe place to go to in your home.”
