The same parent storm system is shifting east Tuesday, sweeping through the Deep South with another round of tornadoes, hail and damaging straight-line winds. The National Weather Service Storm Prediction Center has hoisted an uncommon Level 4 out of 5 risk of severe weather, warning of a “regional severe weather outbreak, including potential for strong tornadoes.”
The Weather Service issued tornado watches for southern Louisiana and much of Mississippi Tuesday morning, which were extended into western Alabama in the afternoon. They are in effect into the late afternoon and evening hours.
The watches include Lake Charles, Baton Rouge and New Orleans in Louisiana, Jackson and Hattiesburg in Mississippi and Tuscaloosa in Alabama.
By late Wednesday, there’s a chance of severe weather over parts of the Southeast and southern Mid-Atlantic, including the Carolinas.
There are signs that another round of active weather could be in the cards for April as the calendar flips to peak tornado season. April, May and June represent the months that feature the greatest number of tornadoes, and with reasons to believe this season could be more active than average, the ongoing storms may offer a glimpse of what’s to come.
Dangerous weather targets Deep South on Tuesday
In the Deep South, a level 4 out of 5 risk area encompasses much of Louisiana and southern Mississippi.
Thunderstorms, clustered into a squall line producing heavy rainfall, had become reinvigorated midday Tuesday as they moved into a humid air mass heated by the sun.
The squall line itself was morphing into a QLCS, or Quasi-Linear Convective System Tuesday afternoon. That’s essentially a band of thunderstorms with embedded circulations that can produce brief, quick-hitting tornadoes with little advanced notice. The nascent QLCS will evolve and shift east with time, entering Alabama around sundown and rolling through the state after dark. Alabama is notorious for hosting a high proportion of nocturnal tornadoes.
Concern is greater for what may happen ahead of the QLCS. That’s where “warm air advection” or warm air arriving on a conveyor belt of swift southerly winds will allow for some more isolated, discrete thunderstorm cells to pop. In an environment characterized by high to extreme wind shear or a change in wind speed and/or direction with height any of those cells would become rotating thunderstorms or supercells. Those would have the best chance of more significant tornadoes, one or two of which may reach EF3 or greater strength and remain on the ground for a considerable amount of time.
Since supercells will precede the QLCS, some areas might be exposed to multiple rounds of violent weather. High-resolution computer models are beginning to hint at a disconcerting assortment of supercells that may target eastern Mississippi and west central Alabama around sunset, which could bring an elevated risk of nocturnal tornadoes to places such as Tuscaloosa, Cullman and Birmingham.
It’s important to note that part of the Deep South has a high density of mobile and manufactured homes, which are exceptionally vulnerable to even low-end tornadoes. The bulk of tornado fatalities occur in mobile/manufactured homes or vehicles. It’s imperative that residents of Louisiana, Mississippi and Alabama who reside in a non site-built home solidify adequate severe weather plans before warnings are issued.
Folks sp. in mobile homes need to use today’s quiet wx to solidify plans in case of warnings tomorrow. pic.twitter.com/wlPGz5ZNav
—Jack Sillin (@JackSillin) March 21, 2022
Thunderstorms will move into the Southeast on Wednesday with an attendant Level 2 out of 5 “slight risk” for severe weather. Southern Virginia, the coastal Carolinas, Georgia and the Florida Panhandle could see storms. Widely scattered damaging straight-line wind tastes and an isolated spin-up tornado are possible before the front shifts offshore early Thursday.
In addition to severe thunderstorm hazards, dangerous flooding is probable. The National Weather Service is also highlighting a moderate risk of excessive rainfall and flash flooding in northern Louisiana and Mississippi and northwest Alabama—including Monroe, La, Tupelo and Starkville, Miss., and Huntsville and Decatur, Ala. That’s where moisture pooling north of the warm front will congeal in a sprawling mass of downpours that will train or move over the same areas repeatedly.
Flash flood watches are up in much of that area, where a widespread 2 to 4 inches is expected. Localized totals approaching a half foot can’t be ruled out either. Urban and small stream flooding is possible, with more disruptive flash flooding possible in spots, too.
Storms cause damage, injuries in Texas
The severe thunderstorms and tornadoes that ravaged Texas Monday rapidly fired just west of Interstate 35 around 4 pm local time Monday. They erupted along a dryline, or the leading edge of arid air from the Desert Southwest, blossoming into a warm, moist and “unstable” air mass blowing in from the Gulf of Mexico.
The first damaging tornado of the day struck Jacksboro, about 100 miles northwest of Dallas, where a high school was damaged among scores of other structures.
One person was killed by a tornado and at least seven more hospitalized in northwest Greyson County, Tex., about 60 miles north of Dallas, in the Sherwood Shores community.
Kingston, Okla. also was hit by a damaging tornadomarking the Sooner State’s first of the year.
Several tornadoes were reported just outside Austin.
A significant, destructive tornado crossed Interstate 35 in Round Rock, Tex., just north of Austin, making a direct hit to a tower camera belonging to TV station KVUE.
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 of rotational velocity just 253 feet above the ground. The radar went offline moments later, Initially prompting fears that it was hit — but it was later revealed the radar escaped unscathed.
Tornado damage was also reported in taylorabout 15 miles to the east of Round Rock.
Elginabout 20 miles east of Austin, was also hit by a destructive twister and was the scene of a viral video which showed a pickup truck flipped by a tornado, spun around, but still able to operate once the twister passed:
Jarrell, about 40 miles north of Austin and largely razed by an F5 tornado that killed 27 people May 27, 1997, was hit again.
Farther east, the communities of Crockett and Madisonville, about midway between Dallas and Houston, were also struck by tornadoes, with reports of injuries and individuals trapped. storm chasers took to social media to solicit medical aid and supplies for the hard-hit area.
In all, the Weather Service received more than 100 reports of severe weather and issued dozens of tornado warnings as the siege of storms charged through Central and Eastern Texas.
How rare was the Texas tornado outbreak?
Tornadoes aren’t uncommon in March, but Monday’s tornadoes struck somewhat unusually far south and east for an early spring outbreak. While the chance of a tornado in late March is, historically, nonzero in Southeast Texas, twisters are as much as three times less common than over other parts of the interior Southeast.
That being said, anomalous events do happen, and East Texas is no stranger to strong twisters — even in March. Just last year, for example, intense supercells raked the Panhandle on March 13. Though the tornadoes associated with that outbreak remained over sparsely populated parts of the Lone Star state, radar implied that some may have been violent.
Another recent springtime outbreak impacted East Texas on April 22, 2020. A powerful supercell that day tracked several hundred miles and produced a large EF3, killing two people. The parent thunderstorm dropped tornadoes in three states during its journey, which prompted the issuance of 16 tornado warnings.
Two particularly noteworthy EF4 tornadoes have struck East Texas in recent years, though both were farther north than many of Monday’s twisters. One, on Dec. 27, 2015, ripped through the suburbs of Dallas, killing 10. The other tracked just west of Athens on April 29, 2017. Intense tornadoes become more common in the populous corridors of Texas as spring builds in.