Hurricane Strength - Ernesto Spins West Over Open Sea - Seen Soaking Jamaica Reuters

Sun Aug 5, 2012 6:01pm IST

* Ernesto expected to make landfall in Mexico

* May reach hurricane strength by mid-week

* Tropical Storm Florence forms in eastern Atlantic (Updates with location at 8 a.m. EDT)

By Michael Connor

MIAMI, Aug 5 (Reuters) - Tropical Storm Ernesto kept on a westerly course in the Caribbean Sea on Sunday, and was expected to strengthen slowly over the next 48 hours, soaking Jamaica as it passes the island on its way to the Yucatan, U.S. forecasters said.

Tropical storm conditions were expected to reach Jamaica by Sunday afternoon, and tropical storm conditions were possible along the coast of Honduras by late Monday, the National Hurricane Center said.

Ernesto was following a predicted track that should keep it at sea until a forecast landfall, possibly at hurricane strength , over Mexico's Yucatan peninsula on Wednesday.

The storm was 215 miles (345 km) southeast of Kingston, Jamaica, around 8 a.m. EDT on Sunday, with maximum sustained winds weakening somewhat to 50 mph (85 kph),

Heavy rains were expected throughout Sunday in Hispaniola and Puerto Rico. Three to 6 inches (7.6 to 15.2 cm) were expected in Jamaica. Showers and thunderstorms - sometimes severe - were possible on the islands of Aruba, Curacao and Bonaire off Venezuela's northern coast.

"Ernesto is forecast to become a hurricane in the northwestern Caribbean in a day or two," the U.S. forecasters in Miami said.

Ernesto would be deemed a hurricane if its winds reach 74 mph (119 kph).

Forecasters expect Ernesto to move into the southern Gulf of Mexico by Thursday but it was too early to know whether it could disrupt oil and gas operations in the gulf.

U.S. National Hurricane Center forecasters said another tropical storm, called Florence, formed on Saturday in the eastern Atlantic and was moving west in open waters. As of early Sunday, forecasters said, Florence was about 680 miles (1,090 km) west of the Cape Verde Islands.

With maximum sustained winds of 60 mph (95 kph), Florence was the sixth named storm of the Atlantic-Caribbean hurricane season, moving west-northwest at 15 mph (24 kph). Some strengthening was expected over the next day or two.

August and September are usually the most active months of the Atlantic-Caribbean hurricane season, which runs from June 1 to Nov. 30. (Editing by Jon Hemming and Vicki Allen)