MIAMI (AP) — A tropical storm warning has been issued for a section of Louisiana’s coast as a weather system approaches from the Gulf of Mexico.

The warning is in effect from Cameron, Louisiana, to Intracoastal City.

The system’s maximum sustained winds early Tuesday are near 40 mph. The U.S. National Hurricane Center says some slight strengthening is possible before the system reaches the coast, either late Wednesday or Wednesday night.

Forecasters say the Alabama and Mississippi coasts could be inundated with as much as 15 inches of rain.

The heaviest rains are expected in an area that includes the port city of Mobile, Alabama, and the cities of Pascagoula and Biloxi in Mississippi. The forecast shows an even wider area from southeastern Louisiana into the western Florida Panhandle could receive as much as 10 inches of rain over three days.

The National Weather Service issued an expanded flash flood watch for the area Tuesday, and forecasters say the flooding threat will continue through Thursday night.

As of 5 a.m. Tuesday, the system is centered about 305 miles south-southwest of the mouth of the Mississippi River and is moving northwest near 8 mph.