Severe weather outbreak in the south after tornadoes in Texas

The same mother-storm system shifted east on Tuesday, sweeping through the deep south with another round of tornadoes, hail and damaging winds in a straight line. The National Weather Service Storm Prediction Center raised an unusual level 4 out of 5 risk of severe weather, warning of a “regionally severe weather outbreak, including the potential for strong tornadoes.”

Tornado clocks were in effect from southeastern Louisiana through western Alabama until Tuesday night. The watches included Baton Rouge and New Orleans in Louisiana, Hattiesburg and Meridian in Mississippi and Tuscaloosa in Alabama.

As severe storms swept through Louisiana into central Mississippi Tuesday afternoon, nearly 80,000 customers were without power in the south. The weather service reported that at least one tornado had hit about 7 miles west-northwest of Vicksburg, Miss., Tuesday. Several tornado warnings were active in eastern Mississippi near the border with Alabama around 3:30 p.m. local time, focused in the zone between Tupelo and Meridian. The responsible series of storms was expected to reach Birmingham and Huntsville, Alabama after dark.

With the storm system moving further east on Wednesday, there is a risk of severe weather over parts of the southeastern and southern Mid-Atlantic, including the Carolinas.

There are signs that another round of active weather may be in the cards for April, when the calendar faces the tornado season. April, May and June represent the months that feature the largest number of tornadoes, and with reason to believe that this season could be more active than average, the ongoing storms may provide a glimpse of what’s to come.

Dangerous weather is forecast for Deep South on Tuesday

In the deep south, a level 4 out of 5 risk area encompasses much of Louisiana and southern Mississippi.

Thunderstorms, gathered in a shower line that produced heavy rainfall, had been revived by noon Tuesday as they moved into a moist mass of air heated by the sun.

The squall line itself was turning into a QLCS, or quasi-linear convective system, on Tuesday afternoon. It is basically a band of thunderstorms with embedded circulations that can produce short, fast-hitting tornadoes with a little advanced warning. The incipient QLCS will evolve and shift eastward with time, entering Alabama in the late afternoon and rolling through the state after dark. Alabama is notorious for hosting a high percentage of nocturnal tornadoes.

The concern is greater for what may happen ahead by QLCS. This is where “hot air advection” or hot air arriving on a conveyor belt of rapid southerly winds will allow some more isolated, discrete thunderstorm cells to pop. In an environment characterized by high to extreme wind shifts or a change in wind speed and / or direction with altitude, any of these cells would turn into rotating thunderstorms or supercells. They would have the best chance of more significant tornadoes, one or two of which can reach EF3 or greater strength and remain on the ground for a considerable time.

Since supercells will precede QLCS, some areas may be exposed to multiple rounds of severe weather. High-resolution computer models are beginning to suggest a disturbing array of supercells that may be targeting eastern Mississippi and western central Alabama around sunset, which could lead to an increased risk of nocturnal tornadoes to places like Tuscaloosa, Cullman and Birmingham.

Parts of the Deep South have a high density of mobile and manufactured homes that are unusually vulnerable to even low tornadoes. The majority of tornado deaths occur in mobile and manufactured homes or vehicles. It is imperative that residents of Louisiana, Mississippi, and Alabama who live in an unbuilt home establish adequate weather plans before issuing warnings.

Thunderstorms will move into the southeast on Wednesday with an accompanying level 2 out of 5 “light risk” of severe weather. Southern Virginia, the coastal Carolinas, Georgia and the Florida Panhandle could see storms. Widespread harmful straight gusts and an isolated spin-up tornado are possible before the front shifts offshore early Thursday.

In addition to the danger of severe thunderstorms, there is a likelihood of dangerous flooding. The National Weather Service also highlights a moderate risk of excessive rainfall and flooding in northern Louisiana and Mississippi and northwestern Alabama – including Monroe, La .; Tupelo and Starkville, Miss .; and Huntsville and Decatur, Ala. This is where moisture that accumulates north of the warm front will solidify into a vast mass of rain showers that will train or move over the same areas repeatedly.

Flash-flood watches are up in much of this area, where a widespread 2 to 4 inches is expected. Localized totals approaching half a foot can also not be ruled out. Urban and small-stream floods are possible, with more disturbing lightning floods also possible in places.

Storms cause damage and injuries in Texas

The violent thunderstorms and tornadoes that ravaged Texas on Monday quickly shot just west of Interstate 35 around 4 p.m. local time Monday. They erupted along a dry line, or leading edge of dry air from the southwestern part of the desert, and blossomed into a warm, humid, and “unstable” air mass blowing in from the Gulf of Mexico.

The first damaging tornado of the day hit Jacksboro, about 100 miles northwest of Dallas, where a high school was damaged among dozens of other structures. The weather service rated the tornado as an EF3 on a scale of 0 to 5 for tornado intensity and found that its headwinds reached 140 to 150 mph.

One person was killed by a tornado and at least seven more were hospitalized in northwestern Grayson County, Tex., About 60 miles north of Dallas, in the Sherwood Shores community.

Kingston, Oklahoma, was also hit a damaging tornadowhich marks Sooner State’s first of the year.

Several tornadoes were reported just outside Austin.

A significant, devastating tornado crossed Interstate 35 in Round Rock, Tex., Just north of Austin, directly hitting a tower camera belonging to the KVUE television station.

The same storm produced a tornado that narrowly missed the Fort Hood weather radar, about 60 miles north of Austin. The radar measured 100 mph rotational speed only 253 feet above the ground. The radar went offline moments later, initially raising fears that it would be hit – but it was later revealed that the radar escaped unharmed.

Tornado damage was also reported in Taylorabout 15 miles east of Round Rock.

Elgin20 miles east of Austin, was also hit by a destructive twister and was the scene of a viral video showing a pickup truck flipped by a tornado spinning around but still able to operate when the twister passed:

Jarrell, about 40 miles north of Austin and largely devastated by an F5 tornado that killed 27 people on May 27, 1997, was hit again.

Further east are the communities in Crockett and Madisonville, about halfway between Dallas and Houston, was also hit by tornadoes, with reports of injuries and trapped people. Storm hunters took to social media to seek medical attention and supplies for the hard-hit area. The Crockett tornado was judged and EF2.

In all, the weather service received more than 100 reports of severe weather and issued dozens of tornado warnings as the storms were besieged through central and eastern Texas.

How rare was the Texas tornado outbreak?

Tornadoes are not uncommon in March, but Monday’s tornadoes hit something unusually far south and east of an early spring eruption. While the chance of a tornado in late March is historically not zero in southeast Texas, twisters are as much as three times less common than over other parts of the inner southeast.

That said, abnormal events are happening and East Texas is no stranger to strong twisters – even in March. Just last year, for example, intense supercells hit the Panhandle on March 13th. Although the tornadoes associated with that eruption remained over sparsely populated parts of the Lone Star State, radar suggested that some might have been violent.

Another recent spring eruption hit East Texas on April 22, 2020. A powerful supercell that day tracked several hundred miles and produced a large EF3 that killed two people. The parent thunderstorm dropped tornadoes in three states during its journey, leading to the issuance of 16 tornado warnings.

Two particularly notable EF4 tornadoes have hit East Texas in recent years, though both were further north than many of Monday’s twisters. One, on December 27, 2015, tore through the suburbs of Dallas, killing 10. The other tracked just west of Athens on April 29, 2017. Intense tornadoes are becoming more common in the populous corridors of Texas as spring builds in.