AccuWeather Global Weather Center – March 16, 2021 – AccuWeather forecasters warn that a dangerous severe weather outbreak could put at least 17 states and more than 100 million Americans at risk across the United States this week. Severe thunderstorms will erupt each day through Thursday across parts of the southern U.S., with the greatest threat and potential for tornadoes Wednesday, lasting well into the nighttime hours, and Thursday.
All facets of severe weather ranging from large hail and flash flooding to damaging straight-line wind gusts and tornadoes can occur from Tuesday evening through Thursday evening in what is likely to evolve into a significant severe thunderstorm and tornado outbreak.
“I think the highest tornado threat is going to be Wednesday and Thursday, especially on Wednesday afternoon and Wednesday night,” AccuWeather Chief On-Air Meteorologist Bernie Rayno said, adding that in addition to unleashing all modes of severe weather, there’s another aspect about this outbreak that has meteorologists particularly concerned: “Severe weather will be lingering long after sunset over the next few nights.”
States at risk for severe weather, including at least isolated tornadoes, are Texas, Oklahoma, Kansas, Missouri, Arkansas, Louisiana, Mississippi, Alabama, Tennessee, Kentucky, Illinois, Indiana, Virginia, North Carolina, South Carolina, Georgia, Florida. The threat may expand to portions of West Virginia and Ohio as well.
This graphic shows the approximate start time of the main severe weather and tornado threat. The risk may extend beyond the periods shown, especially from near the Mississippi River eastward.
Even outside of tornadoes, AccuWeather Local StormMax™ wind gusts of 70 mph can occur in the strongest storms during Tuesday night and Thursday. Gusts could be even stronger, with an AccuWeather Local StormMax™ of 80 mph expected in storms on Wednesday and Wednesday night.
Within the zone along the Interstate 20 corridor from eastern Texas and southern Arkansas to Georgia, some thunderstorms can briefly turn severe and produce damaging wind gusts into Tuesday night.
The storms late Tuesday may erupt near or just to the east of the hardest-hit areas of West Texas from this past weekend. At least 19 tornadoes were reported in the region during Saturday, according to storm reports from the National Weather Service’s Storm Prediction Center (SPC).
“The first storms are likely to erupt near sunset Tuesday evening in the vicinity of U.S. Route 83 in Texas and U.S. Route 183 in Oklahoma and press eastward from there,” AccuWeather Senior Meteorologist Paul Walker said.
During Tuesday night, a greater concentration of severe thunderstorms will develop across central Texas, much of Oklahoma, southern Kansas and western Arkansas, where approximately 30 million Americans live.
“While all forms of severe weather can occur in this southern Plains zone during Tuesday night, we expect the main threats to be from large hail and damaging wind gusts,” AccuWeather Lead Storm-Warning Meteorologist Kayla St. Germain said.
Cities at risk for severe thunderstorms during Tuesday night include Dallas and Waco, Texas; Oklahoma City and Tulsa, Oklahoma; Wichita, Kansas; and Fort Smith, Arkansas.
On Wednesday, the threat of severe weather will shift east of these cities, but the potential for large and long-lived tornadoes is expected to increase.
“It is possible that the period from Wednesday afternoon to Wednesday night brings a significant number of tornadoes and may be the biggest period for tornadoes of the multipleday severe weather outbreak,” AccuWeather Meteorologist Matt Benz said.
The threat of violent storms will focus over the lower and middle portions of the Mississippi Valley, much of the upper Gulf Coast, the Tennessee Valley and part of the Ohio Valley, which is home to more than 40 million people. Cities and rural areas stretching from New Orleans, northward to St. Louis and from Tulsa, Oklahoma, to Atlanta are expected to be at risk during part of the period from Wednesday to Wednesday night.