Louisiana declares state of emergency over possible hurricane

A storm swamped New Orleans streets and paralyzed traffic Wednesday as concerns grew that even worse weather was on the way: a possible hurricane that could strike the Gulf Coast and raise the Mississippi River to the brim of the city's protective levees.

Rain swamps New Orleans streets amid fears high water levels could breach levees

David Fox makes a call from his business on Poydras Street in New Orleans after flooding in the city on Wednesday. A storm swamped streets in the area and paralyzed rush-hour traffic, as concerns grew that even worse weather — a hurricane — was on the way. (Matthew Hinton/Associated Press)

A storm swamped New Orleans streets and paralyzed traffic Wednesday as concerns grew that even worse weather was on the way: a possible hurricane that could strike the Gulf Coast and raise the Mississippi River to the brim of the city's protective levees.

By Wednesday afternoon, the National Hurricane Center (NHC) had issued a hurricane watch for parts of the southern coast of Louisiana.

The agency said conditions appeared favourable for a weather system in the Gulf of Mexico to strengthen into a hurricane as it approaches the United States coastline by this weekend. Forecasters said the weather disturbance is expected to become a tropical depression by Thursday morning, a tropical storm by that night and a hurricane on Friday.

The storm is most likely to make landfall west of New Orleans on Saturday, National Weather Service (NWS) senior hurricane specialist Jack Beven said.

Forecasters are calling the weather system "potential tropical cyclone two."

Lines of thunderstorms ranged far out into the Gulf and battered New Orleans, where as much as 18 centimetres of rain fell over a three-hour period on Wednesday, officials said. Forecasters said parts of the central Gulf Coast could see a total of up to 30 centimetres of rain, with up to 46 centimetres in isolated areas.

All that rain turned the city's streets into small, swift rivers that overturned garbage cans and picked up pieces of floating wood. Water was up to the doors of many cars. Other vehicles were abandoned, while kayakers paddled their way down some streets.

At one point, the storm prompted a tornado warning. The NWS said it planned to investigate apparent wind damage to at least one house on Bayou St. John, a channel extending from Lake Pontchartrain.

A car trudges through water on a flooded street in New Orleans on Wednesday in this image obtained from social media. (David Mora/Reuters)

Chandris Rethmeyer lost her car to the flood and had to wade through water more than a metre deep to get to safety. She was on her way home after working an overnight shift when she got stuck behind an accident in an underpass and the water started rising.

"I was going to sit in my car and let the storm pass," she said. "But I reached back to get my son's iPad and put my hand into a puddle of water."

Valerie R. Burton woke up Wednesday to what looked like a lake outside her door.

"There was about three to four feet of water in the street, pouring onto the sidewalks and at my door," she said. "So I went to my neighbours to alert them and tell them to move their cars."

Levees 'in good shape'

Louisiana Gov. John Bel Edwards declared a statewide emergency Wednesday, and said National Guard troops and high-water vehicles would be positioned all over the state in advance of more heavy rain.

"The entire coast of Louisiana is at play in this storm," Edwards said. "No one should take this storm lightly."

He warned that a "considerable" amount of water could over-top levees that hold back the Mississippi River in the New Orleans area as emergency officials prepare for a potential weekend storm.

That's because the Mississippi River is already swollen from spring rains as the weather system builds in the Gulf and could add about a metre of storm surge to the river.

Jalana Furlough carries her son Drew Furlough as Terrian Jones carries Chance Furlough in New Orleans after flooding Wednesday. The city is bracing for more heavy rain, and a possible hurricane that could strike by the weekend. (Matthew Hinton/Associated Press)

Ricky Boyett, a spokesperson for the U.S. Army Corps of Engineers in New Orleans, said the agency was not expecting widespread overtopping of the levees, but there are concerns for areas south of the city. Forecasters expect the river to rise to six metres by Saturday morning at a key gauge in New Orleans. The area is protected by levees that are six to 7.6 metres high, he said.

Army engineers were working with local officials to identify any low-lying areas and reinforce them, Boyett said. He cautioned that the situation may change as more information about the storm arrives.

"We're confident the levees themselves are in good shape," he said. "The big focus is height."

Forecasters expect a broad area of disturbed weather in the Gulf to become stronger this weekend when it threatens the region with torrential rain. Louisiana, Mississippi and Texas are all making preparations for heavy rain and possible flooding.

'Prepare yourself,' governor warns

New Orleans officials have asked residents to keep at least three days of supplies on hand and to keep their neighborhood storm drains clear so water can move quickly.

"If you haven't already prepared yourself and your family for a severe weather event, you need to go ahead and do that," Edwards, the governor, said.

Wednesday's flooding was reminiscent of floodwaters that surprised the city during an August 2017 rain. That flood exposed major problems at the agency overseeing street drainage. It led to personnel shake-ups at the New Orleans Sewerage and Water Board and required major repair efforts.

On Wednesday, the board said 118 of 120 drainage pumps were operational and the agency was fully staffed.

New Orleans has been battered by devastating floods before, including 2005's Hurricane Katrina, which left most of the city under water, killed hundreds of residents and displaced 130,000 people from Louisiana's largest city.

Forecasters said the storm in the Gulf of Mexico is expected to become a hurricane on Friday. (David Grunfeld/The Advocate via Associated Press)

With files from Reuters