Tropical Storm Florence was expected to become a hurricane by Saturday night with rapid strengthening Sunday to become a major hurricane by Tuesday, the latest National Hurricane Center said.
On Saturday morning, the storm had maximum sustained winds of 65 mph and was moving west at 7 mph. It was about 1,400 miles east of Florida.
Its forward speed is expected to increase by early next week on a west-northwest track. Florence is forecast to intensify further as it moves over the warm waters of the Gulf Stream through Wednesday.
Meanwhile, Tropical Storm Helene, which formed Friday, was about 195 miles east-southeast of the southernmost Cabo Verde Islands. It had maximum sustained winds of 50 mph, and was moving to the west at 13 mph.
Tropical Depression Nine was expected to become Tropical Storm Isaac later Saturday. It was 1,680 miles from the Windward Islands with 35 mph winds, moving west-northwest at 6 mph.
The National Hurricane Center was also monitoring a low-pressure system about 600 miles west of the Cabo Verde Islands. It is given a 90 percent chance of development in the next 48 hours.
