Arthur’s ghost is fueling tornadoes and a rare high flood risk for the Gulf Coast

(CNN) — Arthur is no longer a tropical system but its leftover moisture and energy are still fueling a deadly flood threat and severe storms across the Gulf Coast and into the South.

A rare Level 4 of 4 high risk of flooding rainfall was issued by the Weather Prediction Center for parts of Florida, Mississippi, Alabama and Louisiana on Thursday. Arthur’s “ghost”— its lingering, moisture-rich air — is responsible for this very dangerous threat for areas that have been soaked all week.

It’s hard to overstate just how significant these high risk flooding events are. They are issued on fewer than 4% of days per year on average, but are responsible for 80% of all flood-related damage and 36% of all flood-related deaths, WPC research shows.

Dangerous flooding prompted at least three flash flood emergencies — the highest level of warning — in Louisiana and Mississippi mid-morning Wednesday. The storms that prompted a flash flood emergency in Plaucheville, Louisiana, dumped around two feet of rain in just 12 hours, according to the National Weather Service.

Flood watches for the system’s heavy rain have been issued for more than 17 million people along the northern Gulf Coast to as far east as parts of Georgia. Rainfall rates of 3 to 4 inches per hour are possible at times in some of these areas.

Arthur dissipated inland about 35 miles north-northeast of Galveston, Texas, on Wednesday night, according to the National Hurricane Center. But its remnant thunderstorms will continue to push deeper into the South Thursday and generate more flash flooding and tornadoes along the way.

⛈️ Track the storm on CNN Weather for iPhone

Arthur’s remnants have produced multiple tornadoes in southeast Louisiana. An EF1 tornado struck Avondale, Louisiana — just south of New Orleans — early Thursday morning, destroying four homes and causing minor damage to around a dozen others, Jefferson Parish spokesperson Rachel Strassel told CNN.

One mobile home was blown off its cinder blocks and struck a neighboring modular home, she said. A person in the mobile home was tossed to the ground and the neighbor was trapped by the mobile home. Both people were taken to the hospital. The neighbor had a leg injury and the occupant of the mobile home was taken for assessment, according to Strassel.

Winds also shattered the windows of a third home in the area and reportedly blew its occupant out of bed, she said. Vehicles and trees were also damaged. On the east side of Jefferson Parish, the storms damaged office buildings and blew a stationary train off the tracks, Strassel said.

The city of Houma in Terrebonne Parish, Louisiana, was also hit by an EF1 tornado overnight Wednesday. There are reports of damaged homes as well as “significant street and residential flooding,” according to the Houma Fire Department.

A tornado also moved through St. Tammany Parish, northeast of New Orleans, on Thursday morning. “Our area was hit this morning by strong storms. Crews are responding to flooded streets, stalled or overturned vehicles, and downed power lines,” the St. Tammany Fire Protection District 1 posted on social media. Responders conducted “multiple high water evacuations out of homes” in another part of the parish Wednesday, according to parish Fire Protection District No. 5.

Heavy rainfall supercharged by tropical moisture has already left its mark even before Arthur formed — at least two people have died in floodwater in Texas so far this week.

Parts of eastern Texas, Louisiana and Mississippi have picked up more than a month’s worth of rain in just three days, with some accomplishing this in several hours because of such heavy rainfall rates.

Arthur is expected to produce another 5 to 10 inches of rain through early Saturday from central and southern parts of Louisiana east through Mississippi and Alabama, the western Florida Panhandle and western Georgia.

Flooding kills two in Texas

Some locations from southern and eastern Texas to southern Louisiana and southern Mississippi have seen over 6 inches of flooding rain so far. The highest official totals as of Thursday morning were 11.41 inches near Village Mills, Texas, and 11.31 inches near Picayune, Mississippi, according to the Weather Prediction Center.

Totals continued to climb rapidly Thursday afternoon, especially in parts of Louisiana and Mississippi.

New Orleans International Airport picked up their entire June’s-worth of rainfall from midnight to 7 a.m. CT Thursday. June is the rainiest month on average, with 7.6 inches normally falling during the entire month. Thursday is also the rainiest June day on record there, dating back 80 years.

There have been more than 180 reports of flooding across these areas since Sunday afternoon, according to the National Weather Service.

In Bandera County, northwest of San Antonio, a woman was killed after her vehicle was swept into a flooded creek early Monday morning. Her vehicle was found “several miles downstream” and “completely submerged,” the sheriff’s office said in a statement..

Street flooding in Montgomery County, part of the greater Houston metro area, led to several stranded vehicles and at least 10 street closures on Tuesday, according to Montgomery County Sheriff spokesperson Miranda Hahs.

On Tuesday evening, a 15-year-old boy was found dead in Magnolia in Montgomery County, after he entered a flooded retention pond while playing with a group of teenagers near a construction roadway, the sheriff’s office said in a statement to CNN.

Drivers stranded in floodwater have required rescue or assistance in Travis, Bexar and Williamson counties since Monday, according to local authorities.

Homes, buildings and roads flooded in Picayune, Mississippi, where an estimated 8 to 9 inches of rain fell over six hours on Tuesday.

Fire crews rescued a family, including an infant, from a home with knee-deep water, Picayune Fire Department Chief Joshua Abercrombie told CNN, noting floodwater was waist-deep on the road outside the home. Some drivers also got stuck in the flooding in the city, but there were no reported injuries.

“This just dumped a tremendous amount of rain,” Abercrombie said. “We’re not used to flooding in the areas we got it in.”

In neighboring Forrest County, responders rescued a driver from the top of a submerged vehicle, county Director of Emergency Management Glen Moore told CNN. The driver lost control of the vehicle and ended up in a flooded ditch, but was able to climb onto the roof before it became completely submerged.

In Shreveport, Louisiana, the sheriff’s office received 52 calls for water rescues in a roughly six-hour period, Caddo Parish Sheriff’s Deputy John Lane told CNN. He didn’t know how many of those calls ultimately required a rescue. No injuries were reported, he said.

In Waco, Texas, multiple vehicles were stranded in floodwater on parts of Interstate 35 on Sunday night, forcing rescues, according to the Texas Department of Transportation.

Timing the flood threat

Here’s where the biggest flooding concerns are expected in the next few days:

• Thursday to Thursday night: Heavy rain is ongoing over eastern Louisiana and parts of Mississippi and Alabama. This batch of storms will spread as far east as Georgia and the western Florida Panhandle by afternoon and evening.

• Friday to Friday night: The cold front could cause at least isolated flash flooding in much of the South, but the most significant risk is in southern Alabama and nearby parts of southern Mississippi and the western Florida Panhandle.

The-CNN-Wire
™ & © 2026 Cable News Network, Inc., a Warner Bros. Discovery Company. All rights reserved.

CNN’s Karina Tsui and Andrew Freedman contributed to this report.