ATLANTA — More than 45 million people across 14 Southern states are now in the midst of what’s being called a “flash drought” that’s cracking farm soil, drying up ponds and raising the risk of wildfires, scientists said Thursday.

The weekly U.S. Drought Monitor report released Thursday shows extreme drought conditions in parts of Texas, Alabama, Georgia, Kentucky, South Carolina and the Florida panhandle. Lesser drought conditions also have expanded in parts of Arkansas, Louisiana and Mississippi.

Overall, nearly 20 percent of the lower 48 U.S. states is experiencing drought conditions.

The drought accelerated rapidly in September, as record heat combined with little rainfall to worsen the parched conditions, said Brian Fuchs, a climatologist at the National Drought Mitigation Center in Nebraska.

“Typically we look at drought as being a slow onset, slow-developing type phenomenon compared to other disasters that rapidly happen, so this flash drought term came about,” Fuchs said. “The idea is that it’s more of a rapidly developing drought situation compared to what we typically see.”

Fuchs said he expects scientists to have further discussions about flash droughts, and perhaps develop parameters for what constitutes a flash drought.

In Mississippi, wildfires have been on the rise, Gov. Phil Bryant said this week, as he ordered a statewide burn ban. Outdoor burning is also restricted in parts of several other states including Texas, Alabama, Georgia, Tennessee and West Virginia, according to the drought center.

The Drought Monitor is produced by researchers at the University of Nebraska-Lincoln, the National Oceanic and Atmospheric Administration and the U.S. Department of Agriculture.