NEW ORLEANS — Hurricane Sally, one of a record-tying five storms churning simultaneously in the Atlantic, closed in on the Louisiana-Mississippi coast Monday with rapidly strengthening winds of 100 mph and the potential for up to 2 feet of rain that could bring severe flooding.

Storm-weary Gulf Coast residents rushed to buy bottled water and other supplies ahead of the storm, which was expected to reach Louisiana’s southeastern tip around daybreak Tuesday and make its way sluggishly northward into Mississippi on a path that could menace the New Orleans metropolitan area and cause a long, slow drenching.

Forecasters said the Category 2 hurricane could gain strength by the time it nears the coast. It could give Louisiana its second pounding from a hurricane in less than three weeks.

Jeremy Burke lifted things off the floor in case of flooding in his Bay Books bookstore in the Old Town neighborhood of Bay St. Louis, Mississippi, a popular weekend getaway from New Orleans, about 60 miles to the west. The streets outside were emptying fast.

“It’s turning into a ghost town,” he said.

Sally has lots of company during what has become one of the busiest hurricane seasons in history — so busy that forecasters have almost run through the alphabet of names with 21/2 months still to go.

For only the second time on record, forecasters said, five tropical cyclones were swirling simultaneously in the Atlantic basin. The last time that happened was in 1971.

In addition to Sally were Hurricane Paulette, which passed over a well-fortified Bermuda on Monday and was expected to peel harmlessly out into the North Atlantic, and Tropical Storms Rene, Teddy and Vicky, all of them out at sea and unlikely to threaten land this week, if at all.

Sally was about 145 miles southeast of Biloxi, Mississippi, moving at 7 mph. Sally’s sluggish pace could give it more time to drench the Mississippi Delta with rain and push storm surge ashore.

Residents in New Orleans watched the storm’s track intently. A more easterly course could bring torrential rain and damaging winds to Mississippi. A more westerly track would pose another test for the low-lying city, where heavy rains have to be pumped out through a century-old drainage system.

Even with a push toward the east, New Orleans, which is on Lake Pontchartain, will be in the storm surge area, said University of Miami hurricane researcher Brian McNoldy. He said New Orleans “should be very concerned in terms of track.”

The National Hurricane Center forecast storm surges of up to 11 feet, including 4 to 6 feet in Lake Pontchartrain and 6 feet in downtown Mobile, Alabama.

In coastal Mississippi, water spilled onto roads, lawns and docks well before the storm’s arrival. Sally was expected to bring a surge of 10 feet or more.

The town of Kiln, Mississippi, where many homes sit high on stilts along the Jourdan River and its tributaries, was under a mandatory evacuation order, and it appeared most residents obeyed.

Many of them moved their cars and boats to higher ground before clearing out.

Michael “Mac” Mclaughlin, a 72-year-old retiree who moved to Kiln a year ago, hooked his boat up to his pickup truck to take to his son’s house in another part of Mississippi before heading to New Orleans to ride out Sally there with his girlfriend.

“It would be dumb to stay here,” Mclaughlin said. He said his home was built in 2014 to withstand hurricanes, “but I just don’t want to be here when the water’s that deep and be stranded. That wouldn’t be smart.”