“We are not out of the conditions that will cause heavy rainfall for the city of New Orleans,” she said.

But some worry had already begun to drain out of the city. On Saturday afternoon in the historic Faubourg Marigny neighborhood, Ben Speight, an employee of a mule-drawn carriage company, sauntered up to a resident, Christopher Stanton, who was sitting on his stoop.

“You think it’s going to do anything?” Mr. Speight said, referring to the storm.

“Oh, I don’t know,” replied Mr. Stanton, 70. “Maybe a little bit of something.”

Mr. Stanton, a retired respiratory therapist, had seen a house in New Orleans East destroyed by Hurricane Katrina, but this place on Pauger Street was his family’s ancestral home. There was no place he knew better. And he said he was increasingly worried. “Since the last so many years, I’ve seen more flooding than I ever have before. It didn’t used to be like that,” he said.

He showed a cellphone video of floodwaters on Pauger Street just last Wednesday. It had come up to the first step of his stoop. Climate change could be the culprit, he said. “But it could also be that the pumps are so old that they’re not working as well.”

Barry had already collided with plans for the weekend. Officials confirmed that federal immigration raids that were expected this weekend would not take place in New Orleans because of the storm. Flights to and from Louis Armstrong New Orleans International Airport were canceled. The Rolling Stones pushed a Superdome concert originally scheduled for Sunday back to Monday.

At the Will family’s painstakingly restored home outside Baton Rouge, a large red storage unit in the driveway contained belongings that had still not been brought back into the house since the 2016 flood. The couple runs a cake-making business from home, and the storage unit was stuffed with cookbooks. Ms. Will said she expected the storage unit to flood, too, if the river gets as high as its forecast.

If their home did flood again, the couple said they might start over and fix it up again — “or sell everything,” Mr. Will said, half-joking, “and move to the desert where it doesn’t rain.”