NEW ORLEANS, Louisiana — New Orleans residents stocked up on supplies and prepared their homes on Friday as a strengthening Tropical Storm Barry threatened severe rain and flooding when it comes ashore as possibly the first Atlantic hurricane of 2019.

The storm was forecast to bring torrential rains of up to 25 inches (64 cm) in certain places. This could cause life-threatening flooding along the Mississippi River, which has been running at flood stage for months, officials warned. Residents were ordered to evacuate some nearby areas, but the New Orleans mayor said no evacuations were ordered from the low-lying city.

US President Donald Trump declared a state of emergency for Louisiana and the region's oil production was cut in half as energy companies evacuated offshore drilling facilities.

Barry packed maximum sustained winds of 65 miles per hour (100 km per hour) on Friday morning and was centered 100 miles (160 km) southwest of the mouth of the Mississippi River.

Barry will likely strengthen into a hurricane, the National Hurricane Center said, with winds of at least 74 mph (119 km) by the time it reaches the central Louisiana coast on Saturday.

It was forecast to bring a coastal storm surge into the mouth of the lower Mississippi River that winds through the heart of New Orleans, pushing its crest to 19 feet (5.79 m) on Saturday. That would be the highest since 1950 and dangerously close to the top of the city's levees.

New Orleans is already saturated after torrential rains flooded streets on Wednesday.

"If it's worse than the other day, it'd be the worst week since Katrina," said Robert Harris, 61, as he polished his trombone standing on a sidewalk.

Memories of the 2005 storm, which flooded much of the city and killed 1,800 people, are deeply embedded in New Orleans.

The brunt of Barry was expected to skirt the western edge of New Orleans, avoiding a direct hit. Mayor LaToya Cantrell said the city has not ordered any voluntary or mandatory evacuations. But she added that 48 hours of heavy downpours could overwhelm pumps designed to purge streets and storm drains of excess water.

"There is no system in the world that can handle that amount of rainfall in such a short period," Cantrell said on Twitter.

Louisiana Governor John Bel Edwards warned: "The more information we get, the more concerned we are that this is going to be an extreme rain event."

Officials from the US Army Corps of Engineers, which maintains the levees, insisted that no significant breaching of the 20-foot-tall levees in New Orleans was likely.

Mandatory evacuation orders were issued for areas of Plaquemines Parish beyond the levees southeast of the city, and for low-lying communities in Jefferson Parish, to the southwest.

Barry has shut more than 1 million barrels of offshore oil production and the coastal evacuation orders forced one refinery to halt operations.

New Orleans residents who plan to ride out the storm flocked to supermarkets for bottled water, ice, snacks and beer, thronging grocery stores in such numbers that some ran out of shopping carts. Throughout the city, motorists left cars parked on the raised median strips of roadways hoping the extra elevation would protect them from flood damage.

Armani McGriff, a 29-year-old retail worker, said she picked up nonperishable food and candles after the flooding earlier this week.

She remembered how Katrina uprooted her life at the age of 15, forcing her family to move constantly, but she could not decide whether the coming storm posed a real threat.

"Everybody’s unsure," McGriff said. — Reuters