UPDATE 4-Tropical Storm Fay batters Cuba, threatens Florida

(Adds deaths in Haiti, Jamaica)

By Jeff Franks

HAVANA, Aug 17 (Reuters) - Tropical Storm Fay raked Cuba's southern coast with gusty winds and heavy rains on Sunday while tourists fled the Florida Keys as the storm threatened to reach the United States as a likely hurricane.

The sixth storm of the Atlantic hurricane season, Fay has already killed dozens.

Around 50 people died in Haiti when a bus tried to cross a river swollen with rain, adding to the toll after five deaths in Haiti and the Dominican Republic on Saturday.

A middle-aged couple drowned in the Jamaican capital Kingston when their car was caught in a flooded crossing.

The U.S. National Hurricane Center said the storm's maximum sustained winds were 50 miles per hour (80 km per hour), but Cuban forecasters said gusts up to 66 miles per hour (110 kph) had been recorded at Cabo Cruz, which juts into the Caribbean.

Fay was cruising over warm Caribbean Sea waters at 10 mph (17 kph) about 200 miles (330 km) southeast of Havana and 265 miles (430 km) south-southeast of Key West, Florida, the hurricane center said.

The storm was expected to make landfall in Cuba around midnight, cross the island and enter the Florida Straits by mid-morning on Monday.

Hurricane watches were posted along much of Cuba's central and western coast, including Havana. But Jorge Rubiera, chief of Cuba's weather center, said he did not expect Fay to become a hurricane, which has minimum winds of 74 mph (118 kph).

The U.S. hurricane center said Fay would pick up steam once it is back over water and possibly hit the Florida Keys on Monday night as a hurricane. Hurricane watches were posted in the Keys and along Florida's west coast.

Heavy rains were reported in some Cuban coastal provinces but so far only minor flooding and damage had occurred. Rains up to 8 inches (20 cm) were possible, the Cuban Meteorological Institute said.

People in flood-prone areas had been evacuated, along with foreign tourists at coastal resorts in the storm's path, they said.

GUANTANAMO CARNIVAL

In Guantanamo, the weather was not bad enough to stop the annual Carnival celebration, said Pedro Alvarez, 35, a resident of the coastal city that neighbors the controversial U.S. military detention center where the Bush administration holds more than 200 accused terrorists.

"Up to now there has been just a very light, off-and-on rainfall, so much so that last night the people continued celebrating Carnival," he told Reuters.