(AP) MIAMI - Tropical Storm Debby crawled slowly closer to the northern rim of the Gulf of Mexico on Sunday, its exact track still uncertain as forecasters warned the system could begin strengthening and produce near hurricane force winds in coming days.

Amid an ongoing threat of torrential downpours from Debby, authorities warned of the possibility of flooding and strong winds from Texas to Florida. At least one tornado linked to the storm touched down Saturday in southwest Florida, but no injuries were reported. Heavy squalls pounded parts of that state.

At 5 a.m. EDT Sunday, Debby was about 165 miles southeast of the mouth of the Mississippi River, with maximum sustained winds of 50 mph, the National Hurricane Center in Miami said.

Debby was moving toward the north at 3 mph and was expected to strengthen as it gradually takes a more westward direction in coming hours.

The center of Debby was expected to linger in the northern Gulf over the next few days with no landfall in the immediate forecast.

Forecasters said Debby could be near hurricane strength by Monday night. Meanwhile, up to six inches of rain along the coast, with isolated amounts of 10 inches were possible.

It was the first time four tropical storms have been recorded before July 1 during the Atlantic hurricane season since record keeping began in 1851.