MIAMI — Tropical Storm Hanna is on a wobbly path about 600 miles east-southeast of Miami, but forecasters said it could become a hurricane by Thursday somewhere off the Central Florida coast.

Hanna, the eighth named storm of the 2008 Atlantic hurricane season, had intensified briefly, but then its maximum winds pulled back to 45 mph Sunday as it moved northwest past Turks and Caicos Islands toward the Bahamas.

South Florida is within the latest five-day forecast cone issued by the National Hurricane Center, but forecasters acknowledged the storm's path is far from certain and its organization is "rather ragged."

Some forecasting models show the storm moving north toward the Carolinas late in the week while others point it southwest toward Cuba. The official forecast leans toward the northern path, but forecasters hope to get a better handle on Hanna's track once it interacts with a ridge of high pressure along the U.S. East Coast.

"We know that Hanna is out there," Florida Gov. Charlie Crist said Sunday in Tallahassee. ''We don't know how strong she's going to be."

And if Hanna and Hurricane Gustav weren't enough, hurricane center forecasters continued to monitor a cluster of thunderstorms off the west coast of Africa that has a high probability of forming into a tropical depression. The system had moved west of the Cape Verde Islands on Sunday, about 3,200 miles from Miami.

"Conditions appear to be conducive for development," hurricane center forecasters noted, giving the system a greater than 50 percent chance of becoming a depression.

The ninth named storm of the hurricane season would be Ike.

Miami Herald staff writer Mary Ellen Klas contributed to this report.