Sept. 19 (Bloomberg) -- Tropical Storm Rita maintained its track toward the southern Florida coast with maximum sustained winds of 50 mph (80 kph) and higher gusts that are expected to strengthen to hurricane force later today.

Rita's center was located about 295 miles (480 kilometers) north-southeast of Nassau, the Bahamas, at 11 p.m. Miami time last night, according to the latest advisory on the Web site of the National Hurricane Center. The season's 17th named storm is moving west-northwest at about 10 mph (16 kph) and is expected to continue on this path for the next 24 hours.

A hurricane warning is in effect for all of the Florida Keys and Florida Bay from Ocean Reef southward and westward to Dry Tortugas. Tropical storm warnings are in place further north on the Florida peninsula and for the southwest and central Bahamas.

``Additional strengthening is forecast during the next 24 hours and Rita could become a Category One hurricane by late Monday,'' the advisory.

Tropical storm force winds extend outward as far as 70 miles and are expected to strengthen in the next 24 hours. A tropical storm has sustained winds of 39 to 73 mph. A hurricane has sustained winds of 74 mph or more.

Category One is the lowest on the five-step Saffir-Simpson scale. Wind speeds are between 74 and 95 mph in a Category One hurricane with a storm surge of as high as 5 feet above normal.

Such storms can damage unanchored mobile homes, trees and other shrubbery, according to the Miami-based Hurricane Center.

The center's forecasters said last month the June 1-Nov. 30 season will be worse than previously predicted, producing as many as 21 tropical storms, 11 of which may become hurricanes.

That compares with a forecast in May of 12 to 15 tropical storms and seven to nine hurricanes.

To contact the reporter on this story: Aaron Sheldrick in Tokyo at asheldrick@bloomberg.net.

Last Updated: September 19, 2005 01:40 EDT