Southeastern Louisiana and parts of the northern Gulf of Mexico came under a tropical storm warning as Debby slowed and intensified, prompting the governor to declare a state of emergency.
On Sunday morning, the National Hurricane Center projected Debby could make landfall as a hurricane in Plaquemines on Wednesday. But a number of conditions left forecasters unable to say exactly where Debby would end up. Storm warnings were issued from Florida to the middle of Louisiana.
It appeared the storm was moving to the northeast rather than west, as had been predicted Saturday.
Forecasters said the latest projections were for up to 8 inches of rainfall and coastal flooding up to 6 feet in isolated spots.
Still, as of Sunday morning, no evacuations had been ordered.