(Updates storm location, details)
MIAMI, July 8 (Reuters) - Tropical Storm Chantal churned across the Atlantic Ocean toward the eastern Caribbean on Monday on a track that would put it over flood-prone Haiti and the Dominican Republic later this week, U.S. forecasters said.
The third named storm of the 2013 Atlantic hurricane season posed no immediate threat to U.S. oil and gas operations in the Gulf of Mexico.
But while a track forecast from the Miami-based National Hurricane Center showed it turning away from the gulf after cutting across eastern Cuba early Friday, meteorologists said the forecast was still subject to possible change.
On the current track forecast, the storm would likely head back out to sea after skirting across the eastern coast of Florida and crossing the Bahamas on Saturday.
Chantal, which had winds of about 45 miles per hour (75 kph) on Monday as it swirled 390 miles (630 km) east-southeast of Barbados, was not forecast to strengthen into a hurricane. It was speeding westward at 26 mph (43 kph).
A tropical storm watch was in effect for the Virgin Islands. Tropical storm warnings were also issued for the eastern Caribbean islands of Barbados, Dominica, Saint Lucia, Martinique and Guadeloupe.
The storm is expected to reach near hurricane strength as it approaches Haiti and the Dominican Republic on Wednesday, but lose some of its power passing over the mountainous Hispaniola island made up of the two countries.
Jeff Masters, a hurricane expert with private forecaster Weather Underground, said it was rare for a tropical storm to form east of the Lesser Antilles Islands before mid-July. The hurricane season's traditional busy phase runs from mid-August to October.
He said storm prediction models were forecasting the formation of another tropical storm southwest of the Cape Verde Islands early next week.
"It appears that the Atlantic is primed for an active hurricane season," Masters said. (Reporting by Tom Brown and Kevin Gray; Editing by Gerald E. McCormick and Eric Walsh)