Louisiana Gov. Bobby Jindal declared a state of emergency and New Orleans prepared for possible flooding, with 8 to 10 inches of rain forecast in the next few days.
In its 8 p.m. EDT update, the National Hurricane Center in Miami said the storm, with maximum sustained winds of 45 mph, was about 180 miles west-southwest of the mouth of the Mississippi River and 170 miles southeast of Cameron, La., heading north at 3 mph. A tropical storm warning was in effect from Pascagoula, Miss., west to Sabine Pass, Texas, including New Orleans, Lake Pontchartrain and Lake Maurepas, the center said.
Tropical storm force winds extended out 200 miles, and were expected to reach the coast in the area covered by the warning Friday evening. The storm is forecast to gain strength during the next 48 hours and its center should approach southern Louisiana during the weekend.
Isolated tornadoes were possible Friday night over parts of southern Louisiana and extreme southern Mississippi.
Sustained winds of 60 mph were reported about 65 miles from the mouth of the Mississippi at an altitude of a few hundred feet above the ocean surface, the NHC said. Major oil producers evacuated workers, CNN reported.
The storm could produce rainfall accumulations of 10-15 inches over southern Louisiana, southern Mississippi and southern Alabama through Sunday, the hurricane center said. Isolated amounts could reach 20 inches.
"What we do know is there's high wind, there is a lot of rain and it's going slow," New Orleans Mayor Mitch Landrieu said Thursday. "That's not a good prescription for the city of New Orleans should it come this way."