(Image Credit: AccuWeather)

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 Wednesday 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.”

The first tornado watches on Wednesday stretched across central Arkansas, northern Mississippi, and southwestern Tennessee.

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, and Florida. The threat may expand to portions of West Virginia and Ohio as well.

Even outside of tornadoes, AccuWeather Local StormMax™ wind gusts of 70 mph can occur in the strongest storms on Thursday. Gusts could be even stronger, with an AccuWeather Local StormMax™ of 80 mph expected in storms on Wednesday and Wednesday night.

On Tuesday evening, Texas Gov. Greg Abbott placed resources on standby in preparation for the onslaught of severe weather. “With heavy rain, high winds, and blizzard conditions expected in parts of the state overnight, Texas should be cautious of flood risks and potential damage from this weather event,” Abbott said in a press release.

Storms that developed on Tuesday night primarily produced large hail.

However, there was also a report of a possible tornado in western Oklahoma.

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.

In fact, for the first time since 2012, a “high risk” has been issued by the Storm Prediction Center (SPC) in the month of March. No high risk had been issued in any month since May 2019. A high risk is reserved for days on which significant severe weather is expected.

“It is possible that the period from Wednesday afternoon to Wednesday night brings a significant number of tornadoes and maybe the biggest period for tornadoes of the multiple-day 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.

In preparation for the outbreak, Alabama Governor Kay Ivey issued a state of emergency on Tuesday afternoon ahead of the severe weather.

“This severe weather event, coupled with the COVID-19 public health emergency, poses extraordinary conditions of disaster and of extreme peril to the safety of persons and property within the State,” the statement reads.

The rural, wooded landscape and gentle hills in part of the region will make it challenging for people to spot approaching violent storms on the horizon during the daylight hours. Added dangers will be the risk that some of the storms will be hidden from view by torrential rain or the darkness of night — a factor that AccuWeather forecasters said exemplified the importance of people heeding all warnings.

“We are very concerned about the risk to lives due to the potential for strong tornadoes to occur after dark on Wednesday over the South Central states,” AccuWeather Forecasting Manager Dan DePodwin stated.

And while nocturnal tornadoes are particularly dangerous since they strike at night while most people are sleeping, the region of the country in the line of fire this week is no stranger to this life-threatening phenomenon.

“In parts of the south-central and southeastern United States, nighttime tornadoes are more common than in any other region of the nation,” AccuWeather Senior Meteorologist Mike Doll said.

AccuWeather meteorologists stress that having a means to receive tornado warnings can make the difference between life and death. People have told AccuWeather that push notifications from the AccuWeather app “literally saved our lives” during a severe weather outbreak.

“It’s very important to have a way to get severe weather notifications at all times of the day, but especially at night,” Doll added. “The AccuWeather app can help with this.”

A battery-powered weather radio can also be kept on hand and set to a level loud enough to be a warning should storms approach at night, forecasters say.

The threat of severe thunderstorms in the Southern states will not end Wednesday night. A significant threat will exist in the Southeast where more than 60 million people may be at risk from Thursday to Thursday evening.

On Thursday, storms capable of producing large hail, torrential downpours, damaging wind gusts, and isolated tornadoes are forecast to flare up from northern Florida to southern Virginia and from the southern Appalachians to much of the southern Atlantic coast. Major cities at risk during part of Thursday include Atlanta; Charlotte, North CarolinaColumbia, South CarolinaNorfolk, Virginia; and Tallahassee, Florida.

An additional complicating factor to the nocturnal and rain-wrapped tornado threat will be the potential for flooding during and prior to the violent thunderstorms.

The pattern leading up to the main severe weather threat will favor repeated rounds of rainfall from portions of Louisiana and Arkansas to parts of Georgia and the Carolinas.

The rain will not only be heavy enough to trigger urban and small stream flooding, but it can have some of the rivers in the region on the rise.

High water could block escape routes for some people in rural and suburban areas, making planning ahead of the severe weather event all the more pivotal, AccuWeather meteorologists warn.

People are urged to review their tornado safety plans, closely monitor the weather on a daily basis this week, and have a means to receive severe weather watches and warnings as they are issued. Flashlights should be in working order and generators fueled in case of power outages.

AccuWeather’s team of expert meteorologists will be constantly monitoring the forecast and severe weather set up throughout the week.