KINGSTON, Jamaica -- Tropical Storm Chantal was downgraded Wednesday to a tropical wave as its scattered clouds drifted quickly westward toward Jamaica. But heavy rains from the weakened system continued to drench parts of Haiti and the Dominican Republic and force the evacuation of thousands from flood-prone areas.

One storm-related death was reported in the Dominican Republic: a firefighter swept away by floodwaters.

What was once a fast-moving storm began degenerating late Wednesday afternoon about 230 miles (370 kilometers) east-southeast of the Jamaican capital of Kingston. Its remnants still packed maximum sustained winds of 45 mph (75 kph), but a reconnaissance plane found that Chantal lacked the closed circulation necessary to be classified as a storm.

The U.S. National Hurricane Center in Miami said the wave was expected to spread over Jamaica and eastern Cuba into Thursday. It was projected to move over or near the Florida peninsula by Friday, where heavy wind shear is expected to keep it from reforming as a storm.

Jamaica's Meteorological Service said "the main threat at this time is for outbreaks of heavy showers and thunderstorms," starting over eastern parishes. It warned that flash flooding was possible and called for mariners to stay alert.

As a storm earlier Wednesday, Chantal's center skirted the southern coasts of the Dominican Republic and Haiti, which share the island of Hispaniola. But its heavy rains still posed a threat to some of the region's most vulnerable people, many of whom live in flimsy homes of plywood and corrugated steel.

The only reported fatality was that of Juan Ramon Rodriguez, a 26-year-old Dominican firefighter, in the community of Maimon, about 50 miles (85 kilometers) north of the capital of Santo Domingo. Rodriguez was trying to clear a storm drain when rushing waters carried him away, said Luis Luna, director of the country's civil defense agency.

Dominican authorities were evacuating thousands of people from communities considered at high risk for flooding as rivers near the capital and along the southern coast reached dangerously high levels from the heavy rains. Authorities said more than 6,500 people had been evacuated by Wednesday night.

"We're not in the clear yet," said Juan Manuel Mendez, director of the Emergency Operations Center.

Even remnants of Chantal could create problems for the rural southern peninsula of Haiti and southwestern Dominican Republic. Tropical systems can trigger flooding and landslides on Hispaniola, and severe deforestation and makeshift housing make Haiti especially vulnerable.

Haitian officials urged people to move away from ravines, secure important records and stock up on food and water.

Farmers in southern Haiti, where mountainside crops are particularly vulnerable to strong winds, feared the worst as heavy rain fell. "I'm scared for the people," farmer Jean-Marc Tata said by telephone of his neighbors in Mapou, a village near the southeastern coast.

All tropical storm warnings were cancelled late Wednesday afternoon. But people in Jamaica, eastern Cuba and the Bahamas were urged to monitor the wave's progress.

American Airlines canceled flights to Haiti and elsewhere in the Caribbean, and cruise lines made numerous changes to their itineraries.

Chantal raced through the eastern Caribbean early Tuesday, with officials in Dominica reporting that heavy winds ripped the roofs off over 15 homes and toppled power lines. No injuries were reported there or anywhere else in the small islands of the Eastern Caribbean.

Overnight, the storm passed south of Puerto Rico, leaving about 7,000 people in the U.S. territory without power and more than 2,500 people without water. Gov. Alejandro Garcia Padilla ordered public employees back to work on Wednesday.

In northeast Jamaica, Fredericus Enneking took it easy as gray clouds began swirling overhead and the breeze picked up at his eco-resort on a one-acre seaside property.

"You can feel something is in the air," said the Holland-born Enneking, who uses the Rastafarian name of "Free-I." Of course, you can never know what Mother Nature will do, but I am waiting for the storms later in the season. They are typically the ones that do the damage."