After severe regional flooding Wednesday, New Orleans and the rest of the Gulf Coast are bracing for a tropical storm that could worsen into a hurricane by Saturday with Louisiana already declaring a state of emergency.

The developing storm, which could start Wednesday or Thursday, can become Tropical Storm Barry and bring an additional 18 inches of rain to the region.

In a series of Twitter postings Wednesday, Louisiana Gov. Edwards said "no one should take this storm lightly" and that the heavy rainfall could impact every part of the state.

"This system has the potential to become a dangerous hurricane," the National Weather Service in Lake Charles, Louisiana, wrote on its Facebook page. "The threat for damaging winds and deadly storm surge is increasing."

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New Orleans was hit with a wave of heavy rain and thunderstorms from a tropical disturbance that began forming earlier in the week. The resulting flash floods have caused massive problems to city municipalities, even forcing New Orleans City Hall to close.

Latest projections show Tropical Storm Barry picking up speed within the Gulf of Mexico as it moves towards the coast. The storm could be categorized as a hurricane before making landfall.

Storm watches and warnings have already been issued for much of Louisiana, Mississippi, Alabama and eastern Texas.

New Orleans officials have urged residents to stay home and prepare for the storm, amid serious difficulties and complications from the recent flooding.

Texas Gov. Greg Abbott has also addressed the storm, urging residents to prepare for a wave of heavy rain, thunderstorms, and hurricane-strength winds.

"If you prepare for the very worst, you will be in a situation where you will be able to come out far better in the end,” Abbott said during a press conference. “Begin preparing your property. Begin preparing your supplies. Begin preparing your lines of communication to your family members. Begin preparing to know exactly where it is you will be going to in an event you have to evacuate.”

Tropical Storm Rosa: Flooding, Landslides Expected In US, Mexico
Hurricane Rosa weakened to a tropical storm, while NHC issued flooding, landslide and debris flow warnings in portions of the U.S. and Mexico. In this image, Hurricane Rosa is shown from a National Oceanic and Atmospheric GOES East satelite over the eastern Pacific Ocean on Sept. 27, 2018. Reuters/NOAA Handout