Severe storms, flooding threaten U.S. south into early week

Following large hail and wind damage across the Deep South on Saturday, additional rounds of severe weather and flooding downpours will target these areas and expand eastward through Monday.

Two separate lines of storms pushing northeastward across the Deep South and Tennessee River Valley may cause severe weather to be clustered in two specific areas.

"The first cluster of severe weather is expected to push through South Texas and threaten communities from Laredo to McAllen and Corpus Christi on Sunday morning," AccuWeather Senior Meteorologist Kristina Pydynowski said.

These storms will move rapidly northeastward as an intense squall line this afternoon, rumbling through Houston and Baton Rouge, Louisiana, prior to sunset.

More isolated severe storms may fire up both ahead of and behind this organized line across the lower Mississippi Valley and eastern Texas.

"The second area of severe weather may ignite around Little Rock and Memphis on Sunday morning before pressing northeastward over parts of the Tennessee and Ohio River valleys during the rest of the day," Pydynowski added.

These storms will likely lose some of their intensity by the time they reach Nashville, Tennessee, and Louisville, Kentucky, on Sunday afternoon, but will still be capable of producing brief torrential downpours and strong winds.

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The main threats from all of the rounds of severe weather will be damaging winds, hail and flooding downpours.

There may also be isolated tornadoes, especially in association with the storms in Texas and Louisiana.

By Sunday night, the severe weather threat will shift eastward into Mississippi and eastern Louisiana and return to western Tennessee.

"The after-dark severe weather risk will make it important for residents to keep their cell phones on and charged with audible severe weather alerts enabled throughout the night," according to AccuWeather Meteorologist Renee Duff.

"Motorists along stretches of interstates 10, 20, 30, 35, 49 and 55 may face sudden reductions in visibility and a heightened risk of hydroplaning while traveling at highway speeds," according to Pydynowski.

With the soil becoming saturated due to the repeating downpours, wind gusts as low as 40 to 50 mph may be sufficient to knock down trees and power lines.

Gusts of 60 to 70 mph will be possible in the most intense storms, and winds of this magnitude can cause property damage and turn loose objects into dangerous projectiles.

Download the free AccuWeather app to find out when severe weather is likely in your community.

By Monday, the threat for heavy, gusty storms and repeating downpours will shift eastward into the Southeast and the Carolinas.

Although the threat for severe weather will be less severe than that of Sunday, a few incidents of wind and hail damage cannot be ruled out.

However, the main threat from the storms on Monday will be flash flooding triggered by torrential rainfall in a short amount of time.

Flooding of low-lying and poor-drainage areas, as well as small streams and creeks, is likely.

In areas hit by the heaviest downpours, streets and roadways may become temporarily submerged by larger rivers overflowing their banks.

Motorists should avoid flooded roadways. It only takes 1 to 2 feet of moving water to cause most vehicles to stall or get swept away.

In addition, the prolonged period of wet, stormy weather will only exacerbate and worsen the ongoing flooding issues on the Mississippi River and its tributaries.

Through Monday night, the highest rainfall totals of 3 to 6 inches are forecast to extend from eastern Texas and western Louisiana into southeastern Arkansas, northern Mississippi and western parts of the Tennessee Valley.

In these areas, an AccuWeather Local StormMax™ of 10 inches will be possible.

Outside of these areas, rainfall amounts of 1 to 3 inches will be most common.

Although dry weather is expected to return during the middle of the week, the weather pattern will remain favorable for more rounds of thunderstorms and heavy rain through at least the third week of April.