A regional outbreak of severe thunderstorms, with damaging gusts of up to 75 miles per hour, hail as large as billiard balls or larger, and several tornadoes — including some that could be “intense” — is expected Thursday into Friday across a swath of the country from Texas to Tennessee, forecasters warned.
Over 30 million people living in the South are being told to prepare for the possible severe weather in their areas.
When forecasters predict that a “regional severe weather outbreak” is likely, they believe the coverage and intensity (and potential impacts) of severe weather will be substantial within a relatively concentrated area, said Matthew Elliott, a meteorologist with the Storm Prediction Center.
Some thunderstorms formed already on Thursday morning, but the more dangerous storms were not likely to pick up until the afternoon, forecasters said. The storms could come in multiple waves, said Chris Nuttall, a meteorologist with the Shreveport, La., forecast office. These first storms from late Thursday afternoon through the evening pose the greatest threat for significantly large hail — about the size of a billiard ball or larger — and a few strong, potentially long-lasting tornadoes across the Arkansas, Louisiana and Texas region.
This region (sometimes called Ark-La-Tex) is under a “moderate risk” of severe storms, forecasters at the Storm Prediction Center said on Thursday morning. A moderate risk means forecasters believe that the storms that form in the area will be at a strength typically only experienced once a year, if that.
“Moderate risks and higher risks are saved for those days where it looks like an outbreak,” Mr. Nuttall said. “We get lots of severe weather days during the year, but we don’t typically have this great of confidence combined with the unusually strong storm system.”
These outlooks are typically only issued about a dozen times a year on average. This is only the second one issued this year. The last was issued this past Sunday when damaging winds and tornadoes tore through parts of Oklahoma.
However, Mr. Nuttall cautioned residents to avoid getting caught up in what level of risk they were in; if you are in any risk area, there is a chance you could be affected, he said.
The second wave of storms will begin near Dallas late Thursday afternoon before sweeping east through the evening hours, across Louisiana and Arkansas overnight, and into tomorrow morning across western Tennessee and down through Mississippi.
Extreme winds will be an extensive threat with this line of storms, bringing the risk of more tornadoes.
“It is looking pretty likely we’re going to have some pretty strong winds not only during the storms as they’re moving through but even after the fact,” said Hunter Reeves, a meteorologist at the Dallas-Fort Worth office of the National Weather Service.
But it isn’t just severe winds, hail and tornadoes that forecasters are worried about. It is also the risk of excessive rainfall. Portions of Texas, Oklahoma, Missouri, Kentucky, Tennessee and most of Arkansas are at risk for rain that could lead to flash flooding Thursday into Friday.