Tropical downpours to unleash 12 inches over flood-weary south-central US

The combination of a slow-moving non-tropical storm and a weak tropical disturbance loaded with moisture will unleash torrential rain and raise new concerns for flooding over the south-central United States into this weekend.

Moisture was already streaming northward from the upper Texas coast to Mississippi during Wednesday morning and will continue for several days over part of the lower Mississippi Valley.

Radar snapshot 6/5 10:30 AM

Radar shows heavy rainfall dousing the Texas coast on Wednesday, June 5, 2019. (AccuWeather Interactive Radar)

 

Hourly rainfall of 1-3 inches can occur with daily rainfall averaging 3-5 inches.

A daily AccuWeather Local StormMax™ of 6 inches is forecast.

Flooding Rain Through Wednesday night

However, there is the potential for some areas of the Interstate 10 and 20 corridors to receive a foot or more of rain from the multiple-day event that may last through the weekend.

Rainfall of this magnitude will trigger street and poor drainage area flooding, initially. Motorists should be prepared for road closures, substantial delays and the need to alter their routes. To drive through flooded roadways is extremely dangerous.

Flooding Rain Thru Monday 11 am

Cities such as Houston and Beaumont, Texas, and New Orleans, Lake Charles and Baton Rouge, Louisiana, will be at risk for inundation in some neighborhoods.

Some small streams and bayous will flood and ultimately trigger river flooding in areas that have not had such problems recently.

Home and property owners prone to flooding should be prepared to move valuables and seek higher ground.

To complicate matters, heavy rainfall over the Central states and melting snow from the Rockies has created a surge of water from the Missouri and Arkansas rivers that is emptying into the Mississippi River and flowing southward.

Over the lower part of the Mississippi Valley, this surge of water may occur at nearly the same time that heavy rain falls.

The combination thereof could result in record-challenging high water on the lower Mississippi River, especially where the water levels are not mitigated by spillways toward the middle and into the latter part of June.

Mississippi River at Red River Landing, La.

Official forecast levels from Wednesday could be underdone over part of the Southern states along the Mississippi and other rivers depending on how far inland torrential rain occurs.

The opening of the Morganza Spillway on the Mississippi River above Baton Rouge has been pushed back to June 12, based on National Weather Service hydrologist forecasts, according to The Associated Press.

Morganza Spillway from May 18, 2011

In this May 18, 2011 file photo, floodwater is seen rushing from the Mississippi River, above right, into the Atchafalaya Basin through open bays of the Morganza Spillway in Morganza, La. As the Mississippi River rises, the Army Corps of Engineers plan to open the Morganza Spillway will be opened for the third time ever - and only the second time for flood control on June 12, 2019. (AP Photo/Rich Matthews, File)

 

The spillway would be overtopped if not opened with the anticipated level of water. The release of water at the spillway and the Old River structure diverts some water from the main stem of the Mississippi River and creates flooding in the Atchafalaya River Basin.

The back edge of the heavy rain is forecast to make slow eastward progress this weekend.

Much of eastern Texas should be in the clear from rain by Saturday. However, runoff from rains through Friday will continue to cause flooding problems.

It may take until Monday or Tuesday before the rain departs the lower Mississippi Valley.

On a positive note, the heaviest rain will pass south and east of hard-hit flood areas of Oklahoma, Kansas, Iowa and northern and western Missouri. This may allow rivers and streams in the area to further recede.

As the corridor of torrential rain advances eastward, it will reach needy areas of the southeastern U.S. late this week and this weekend. The rainfall could provide relief from drought and abnormally dry conditions that have been building across the region. However, even in some of these eastern areas, too much rain could fall and may result in flooding.

Download the free AccuWeather app to receive the latest flood watches, warnings and advisories for your area. Keep checking back for updates on AccuWeather.com and stay tuned to the AccuWeather Network on DirecTV, Frontier and Verizon Fios.

16 PHOTOS
2019 spring weather across the US
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2019 spring weather across the US
A vehicle drives through Mississippi River flood water in downtown Alton, Il. on Monday, May 6, 2019. Flooding from the Mississippi River closed streets in downtown, forced the closure of Argosy Casino and flooded the basements of several businesses. The Mississippi River is expected to crest at 34.8 feet later on Monday, almost 14 feet above flood stage. The red painted line beneath the American flag on the grain silos denotes the height of flood water in 1993. (David Carson/St. Louis Post-Dispatch via AP)
Water from the swelling Mississippi River covers roadways and surrounds houses on Saturday, May 4, 2019 in Foley, Mo. he National Weather Service at St. Louis says rain in the coming days will determine whether Mississippi River levels will rise more than expected. A flood warning continues for areas on either side of the river from Minnesota all the way to Louisiana, where the river empties into the Gulf of Mexico.(Colter Peterson/St. Louis Post-Dispatch via AP)
A runner makes his way along South Grandview Ave. during a snowfall Saturday, April 27, 2019 in Dubuque, Iowa. (Dave Kettering/Telegraph Herald via AP)
John Love of Pacific Junction, Iowa, stands in flood water to wash the muck off of his golf clubs which were in a flooded shed Thursday, April 18, 2019. The mandatory evacuation of the city during the flooding from the Missouri River has been lifted Thursday and residents and owners were allowed to return to their property to determine the viability of their premises. (AP Photo/Nati Harnik)
Marissa Whitman, 20, wades in about 3 feet of floodwater from the swelling Mississippi River, while guiding a boat carrying her boyfriend Brendan Cameron and his mother, Tory Cameron, to their home along Pet Street, Sunday, May 5, 2019, in East Foley, Mo. "I just need to see if the water reached inside," said Tory. The family had to evacuate Saturday when the water rose suddenly. (Laurie Skrivan/St. Louis Post-Dispatch via AP)
A van stands in floodwaters as cornstalks cover its roof after a flood inundated Pacific Junction, Iowa, Thursday, April 18, 2019. The mandatory evacuation of the city during the flooding from the Missouri River has been lifted Thursday and residents and owners were allowed to return to their property to determine the viability of their premises. (AP Photo/Nati Harnik)
Floodwaters surround a home, Wednesday, May 29, 2019, in Ottumwa, Iowa, as rising waters from the Des Moines River has forced residents out of homes along the riverbank. (Matt Milner/The Ottumwa Courier via AP)
Residents load sandbags onto a truck Wednesday, May 29, 2019, in Ottumwa, Iowa, as floodwaters from the Des Moines River has forced residents out of homes along the riverbank. (Matt Milner/The Ottumwa Courier via AP)
In this Tuesday, May 22, 2019 photo, a late-spring snowstorm fell in Red Cliff, Colo. The unusually cold weather impacted other parts of the West, including California, that were hit by late spring storms. A storm dumped heavy, wet snow in Colorado and Wyoming, cancelling flights and snapping newly greened up tree limbs. (Chris Dillmann/Vail Daily via AP)
Frisco resident Dianne Stuhr walks with her dogs, Winston and Patty, Tuesday, May 21, 2019, along Tenmile Creek in Frisco, Colo. Nearby Breckenridge Ski Resort reported 9 inches of snow overnight. (Hugh Carey/Summit Daily News via AP)
This image from a Caltrans traffic camera shows traffic moving along Interstate 80 past new snow Thursday, May 16, 2019, at Donner Summit, Calif. Slopes of the Sierra Nevada sported fresh powder Thursday as a late-spring storm with a winter-like potency moved through California, adding to snowpack and rainfall accumulations that were already well above normal. (Caltrans via AP)
In this May 10, 2019 photo, flood waters from the Missouri River flow through a break in a levee, north of Hamburg, Iowa. Communities that were flooded when levees failed along the Missouri River earlier this spring will likely remain exposed to high water for months to come. More than 40 levees were damaged but only a handful of construction contracts to fix them have been issued. (AP Photo/Nati Harnik)
Repair and cleaning efforts begin on a neighborhood damaged by a tornado storm system that passed through the area, destroying homes and cutting off access to utilities, Wednesday, May 29, 2019, in Dayton, Ohio. Tens of thousands of Ohio residents were still without power or water Wednesday in the aftermath of strong tornadoes that spun through the Midwest. (AP Photo/John Minchillo)
Repair and cleaning efforts begin on a neighborhood damaged by a tornado storm system that passed through the area, destroying homes and cutting off access to utilities, Wednesday, May 29, 2019, in Dayton, Ohio. Tens of thousands of Ohio residents were still without power or water Wednesday in the aftermath of strong tornadoes that spun through the Midwest. (AP Photo/John Minchillo)
People watch from the Liberty Memorial as a severe storm that dropped several tornados earlier approaches downtown Kansas City, Mo., Tuesday, May 28, 2019. (AP Photo/Charlie Riedel)
In this aerial image, debris from damaged homes litters the properties on Fairground Road after a tornado storm system passed through the area the previous night, Tuesday, May 28, 2019, in Celina, Ohio. A rapid-fire line of apparent tornadoes tore across Indiana and Ohio overnight, packed so closely together that one crossed the path carved by another. At least half a dozen communities from eastern Indiana through central Ohio suffered damage, according to the National Weather Service. (AP Photo/John Minchillo)
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