Weather News: Strong tornadoes could hit major cities in the South


“The SPC outlook uses phrases such as those that have been used in recent days only when environmental conditions appear favorable for more widespread and elevated severe weather potential,” CNN Chief Operating Officer Bill Bunting told CNN. forecast at SPC.

The global storm system was expected to start Monday in Texas before moving into the Deep South on Tuesday.

More than 30 million people are at risk of severe storms capable of producing a tornado through Tuesday. If you live in or near these cities listed below, you want to prepare.

This dynamic system presents multiple hazards, ranging from huge hailstorms to strong tornadoes.

“Long story short, all the variables are finally in place for this event,” the National Weather Service (NWS) of New Orleans wrote Monday morning.

The latest events have not seen all of these severe weather variables working together simultaneously.

The combination of warm, moist air colliding with drier air and a stream of intense winds in the atmosphere is not just getting news agency meteorologists like me, but researchers too. These scientists are now deploying across the South to study this system to learn more about these dangerous storms.

The National Weather Service has issued a tornado watch for parts of central and northern Texas through 10 p.m. CDT Monday. About 14 million residents were under surveillance, including residents of Austin, Dallas and San Antonio.

A few tornadoes have the potential to be intense (EF-2 and above) and the storms could produce hail up to 3 inches in diameter and wind gusts to 75 mph, forecasters said.

Storm timeline

“Thunderstorms will begin rolling in at noon on Monday and will quickly become severe in eastern Texas and much of Oklahoma,” CNN meteorologist Chad Myers said.

Slight risk, level 2 out of 5, for severe storms includes parts of Oklahoma, Arkansas, Louisiana and Texas. Higher and increased risk, level 3 out of 5, and includes most of the eastern half of Texas. An even higher moderate risk, level 4 out of 5, includes Austin, Texas.

After dark, thunderstorms will continue to move east. They will likely line up, charging east with every possible form of severe weather. Before midnight, the strongest weather will approach Little Rock, Shreveport and Houston, Myers said.

One thing we will need to pay close attention to is the individual storms that form ahead of this line, he adds. They will be east of the line and therefore sooner to arrive than the line of storms itself.

Individual storms, called supercells, will likely spin and create the greatest tornado threat, Myers noted. “So watch out and pay attention to the timing on these!”
Find out how a storm produces a tornado

The storms will continue through Tuesday with even the possibility of a third round in Houston and eastern Texas on Tuesday morning, but our attention will shift east to Louisiana, Mississippi and Alabama throughout throughout the day.

The worst will center on Louisiana and Mississippi, where Moderate Risk, Level 4 out of 5, includes Baton Rouge in Louisiana and Jackson in Mississippi.

“The risk for tomorrow will be greater during the day, which is a good thing for people to be more awake and alert,” Joanne Culin of the NWS office in Jackson told CNN. “Unfortunately, we’re going to be tapping more into that daytime instability and fueling the thunderstorms.”

Just south of the center of the target is New Orleans, which is in the heightened risk level, level 3 of 5.

“High and destructive winds” are possible, said Tim Erickson of the NWS office in New Orleans. “Tornadoes won’t be out of the question at all,” he added.

This area just north of New Orleans is where scientists are beginning to deploy mobile radars, lightning mapping arrays and dozens of other instruments as part of a joint research project called PERiLS. .

“Our target area is east-central Mississippi and west-central Alabama,” Tony Lyza, coordinator of NOAA’s involvement with PERiLS, told CNN.

Scientists say ‘never let your guard down’ in the Southeast

“You never let your guard down in the Southeast,” Christopher Weiss, a professor of atmospheric science at Texas Tech, told CNN.

“It’s not just that they have tornadoes. But there are other factors – you can’t see them very well because of the hills and the trees.”

Jennifer and I both went out in the field with Weiss as he extended the instruments called sticknets in front of an approaching storm.

They look like yellow tripods with devices on top that spin with the wind.

Chris Weiss (left) deploys a sticknet before a storm in 2016.

It was to have 16 instruments on Monday to begin capturing wind and pressure data. Then on Tuesday they will monitor the data and as specific storms begin to form, it will deploy eight more in the path of the potential tornado storm, usually in an area awaiting a tornado warning.

“About an hour before the line arrives, we will deploy our remaining eight probes, ahead of the line,” he explained. “So it’s going to be dangerous.”

They drive quickly along a highway stopping at a good open spot. All the doors open as his team gets out of the truck, grabs a net out of the trailer, pulls it out, unfolds it. A running team member with a hammer begins to drive it into the ground. Another grabs and attaches the instruments and transmitter. Then they run to the truck.

As Jenn and I raced with them years ago, you can feel your heart racing as you pull your seat belt across your chest.

Then they rush to another spot on the road, trying to deploy the eight.

“We have to be very careful, of course, of the approaching storm, the threat of a tornado, of course, but also of lightning,” he added.

Tomorrow, he will not be the only scientist in the field. A group of them from nine universities, three divisions of NOAA and the NSF are meeting on Tuesday to better understand dangerous tornado storms.

They can come with little warning

Look, as meteorologists, we cringe every time we hear someone interviewed after a tornado say these words, “It happened without warning.”

The National Weather Service does an amazing job of issuing advance warnings. Not to mention the past days, they begin to tell people the likelihood of severe storms.

The strongest and most intense tornadoes usually occur from supercells, forming before the main line of storms. They’re easy to chart on radar, and in a way, it’s easier to warn people.

Know the difference between a tornado watch and a warning

But the group is studying tornadoes that can form in a line of storms.

“Tornadoes can, and tend to, turn with very little warning, sometimes even a short enough amount of time to fall between weather service radar scans,” Weiss pointed out.

“So that’s what we’re going to be focusing on here as we’re trying to learn more about how tornadoes are spawned by these linear storms, in particular.”

“A lot of these tornadoes tend to happen at night, of course. That’s part of what makes this part of the country so attractive for this type of project, because there are so many different ways storms can affect people there.”

Night-time, rain-shrouded tornadoes

Monday evening and Tuesday evening there will be a risk of nighttime tornadoes, which is an incredibly dangerous scenario.

People can be caught off guard when alerts wake them up in the middle of the night.

“People, of course you know they’re sleeping, need a way to wake up whenever your severe weather alarm goes off,” Erickson said.

He thinks there will be a line somewhere around New Orleans that will be a threat there before or around midnight, and maybe even into the morning.

It’s not just the darkness that could keep you from seeing the tornado coming. The air is so humid in the south that rain often wraps around tornadoes and it can be difficult to see them.

Heavy rain will make it extremely difficult to view tornadoes, as tornadoes could become enveloped in rain fairly quickly, the Dallas NWS said.

The WPC has also issued a Moderate, Level 3 out of 4, risk of extreme precipitation for many of the same areas that could see tornadoes today and tomorrow.

This means that beyond rain-shrouded tornadoes, there will be the threat of flash flooding from Texas to Alabama. Flood watches were issued Monday along the Gulf Coast states from Texas to Mississippi, and they could extend to Alabama later in the day.

The threat of flooding will be greatest where storms form over the same areas “and drop an enormous amount of precipitation and locally up to six inches or more is certainly not out of the question,” it said Monday. the NWS office in Shreveport.

CNN meteorologists Taylor Ward and Jennifer Gray contributed to this article.


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