Rain bands from Tropical Storm Lee are hitting Louisiana's gulf coast as the storm moves closer to the state.

The National Hurricane Center says Lee could dump 50 centimeters of rain over southern parts of Louisiana, Mississippi and Alabama through Sunday.

It says the center of the storm is expected to reach the Louisiana coast later Saturday.

Lee's approach prompted oil and gas producers to shut down platforms and evacuate workers from the Gulf of Mexico.

Tropical storm warnings have been issued from Mississippi to Texas. New Orleans, Louisiana, which suffered devastating damage in 2005 from Hurricane Katrina, is in the storm's path.

Lee is the 12th named storm of the Atlantic hurricane season.

Meanwhile, crews continue to help residents recover from Hurricane Irene, which ravaged the eastern U.S.

Flooding devastated parts of the states of Vermont, Connecticut, New York, New Jersey and North Carolina. Irene is blamed for at least 45 deaths in the U.S. and five in the Caribbean, and has caused billions of dollars of damage.

U.S. President Barack Obama signed disaster declarations for New York, New Jersey and North Carolina, making federal funding available for recovery efforts. Mr. Obama is scheduled to visit the state of New Jersey on Sunday to view wind and flood damage from Irene.

Meanwhile, forecasters are monitoring Hurricane Katia, which regained hurricane status in the Atlantic on Friday.

Katia, the second Atlantic hurricane of the season, is currently classified as a Category 1 storm on the five-point scale of hurricane intensity, after being downgraded to a tropical storm earlier in the week.

September is normally the peak of the hurricane season. Experts predicted an active 2011 hurricane season with eight to 10 hurricanes possible, which would be slightly more than normal.