Worse than spoiling Halloween parties and trick-or-treating, lives and property will be threatened by severe thunderstorms and isolated tornadoes in the Deep South as flooding rain streams to the Ohio Valley into Thursday.
“A dangerous situation is unfolding from eastern Texas to Louisiana and Mississippi,” AccuWeather Senior Meteorologist Kristina Pydynowski stated. “Severe thunderstorms are expected to sweep across these states through Wednesday night, and isolated tornadoes can be spawned.”
After tearing through eastern Texas, the severe thunderstorms will sweep through Louisiana into early Thursday.
Anyone planning to be outdoors for trick-or-treating or other festivities from Austin to Houston, Tyler and Texarkana, Texas, are strongly urged to download the free AccuWeather app to receive severe weather bulletins as they are issued so you can seek shelter accordingly.
In addition to the tornado danger, the strongest thunderstorms will be capable of producing damaging winds, flooding downpours, hail, and frequent lightning.
The stormy conditions may force some communities to reschedule or cancel Halloween festivities. Houston is among the cities where indoor trick-or-treating options are being offered.
The violent thunderstorms will march across southeastern Texas and the lower Mississippi River Valley on Wednesday night. An isolated severe thunderstorm cannot be ruled out across Louisiana on Wednesday afternoon, but a more widespread danger will arise overnight.
“The tornado danger is not expected to lessen after dark,” Pydynowski said. “Isolated tornadoes, a few of which can be at least EF2-strength, can occur along and ahead of the main line of thunderstorms through the overnight hours.”
“That creates a particularly dangerous situation with the tornadoes hard to see at night and occurring when most people are sleeping,” she said.
Residents in Houston and Beaumont, Texas; Shreveport, Lake Charles, Lafayette, Baton Rouge, and New Orleans, Louisiana; and Natchez and Jackson, Mississippi, should not go to bed without making sure cell phones are turned on to receive life-saving weather alerts.
Motorists planning to travel on stretches of interstates 10, 12, 20, 49, and 55 should remain vigilant of the severe weather danger by listening to local radio stations and be ready to safely pull off the road and seek shelter. Remember that a vehicle is not a safe place to be when in the path of a tornado.
In addition to the tornado danger, the strong wind gusts produced by the thunderstorms can lead to downed trees and power lines. Widespread power outages and home/property damage can result.
The line of severe thunderstorms is expected to continue to press eastward across the northern Gulf Coast states on Thursday.
“The danger is expected to press from New Orleans and Meridian, Mississippi, on Thursday morning to Panama City, Florida, and Columbus, Georgia, late in the day,” according to Pydynowski.
Areas recently battered by Hurricane Michael are among those communities at risk.
“Damaging winds, flooding downpours, and isolated tornadoes can once again be produced,” Pydynowski said.
Flood danger to focus on Ohio and Tennessee valleys
Although areas farther north across the Ohio and Tennessee valleys will not have to face severe storms, persistent downpours and steady, heavy rain will increase the flash flood threat through Thursday.
There can be an AccuWeather Local StormMax™ of 6 inches where rain falls on both Wednesday and Thursday, generally from near Little Rock, Arkansas, to Columbus, Ohio.
While part of this corridor has received below-normal rainfall so far in October, too much rain can fall too quickly and cause flooding issues.
“This much rainfall, despite how dry it has been in recent weeks, can lead to flash flooding when it occurs in such a short amount of time,” AccuWeather Meteorologist Brett Rathbun said.
Not only can the heavy rainfall lead to urban and small stream flooding, but it can also cause major rivers to overflow their banks. Anybody in the flood threat area living along the Ohio and Mississippi rivers and their tributaries should be ready to evacuate and move to higher ground if flood waters threaten.
“Motorists traveling on portions of Interstates 40, 64, 65, 70 and 71 that lie within the threat zone should be prepared for rapidly falling roadway visibility and seek an alternate route if water covers the roadway ahead,” AccuWeather Meteorologist Kyle Elliott warned.
It is impossible to judge how deep any water across a roadway is just by using eyesight alone, and it only takes 2 feet of moving water to sweep away a moving vehicle.
Roadways and sidewalks may be extra slick where the rain dampens fallen leaves.
A shot of much cooler air is expected to follow the severe weather and soaking rain. Drier air will also sweep in from west to east across the Deep South and to the Ohio Valley, leading to a widespread rain-free start to the weekend.