[6:35 p.m. ET] A state of emergency has been declared in Biloxi, Mississippi, in anticipation of Tropical Storm Lee, Mayor AJ Holloway told CNN.
[2:30 p.m. ET] A slow-moving tropical system with the potential to douse summer-ending beach plans and bring up to 20 inches of flooding rain to parts of the Gulf Coast strengthened into a tropical storm Friday afternoon, according to the National Hurricane Center.
Tropical Storm Lee could bring winds of 65 mph when it makes landfall this weekend, CNN meteoroloigist Sean Morris said.
The state of Louisiana and 10 of its parishes had declared states of emergency as of Friday afternoon, Gov. Bobby Jindal said. LaFourche Parish and the city of Grand Isle also issued voluntary evacuation orders, he said.
"This is going to be a slow-moving storm. It's going to bring a lot of rain," Jindal said.
Mississippi Gov. Haley Barbour also declared a state of emergency for portions of southern Mississippi expected to be affected by the storm.
The storm was likely to reach land in the next 48 hours, forecasters said.
The storm is over water as warm as 90 degrees and atmospheric conditions that are limiting its development should become more favorable to strengthening over the next 24 hours, CNN meteorologist Sean Morris said.
Tropical storm-force winds are being reported at several oil rigs in the Gulf, according to Morris and the National Hurricane Center.
The current track suggests a possible landfall west of Morgan City, Louisiana on Sunday morning, Morris said.
Tropical storm warnings were up for the Gulf coast from Pascagoula, Mississippi to Sabine Pass, Texas.