Hurricane Elsa fell back to tropical storm force as it brushed past Haiti and the Dominican Republic and threatened to unleash flooding and landslides before taking aim at Cuba and Florida.
The storm weakened during its approach to Hispaniola and Cuba on Saturday, according to the National Hurricane Centre in Miami.
The long-term forecast track showed it heading toward Florida as a tropical storm by Tuesday morning, but some models would carry it into the Gulf or up the Atlantic Coast.
At least one death was reported in St. Lucia, according to the Caribbean Disaster Emergency Management Agency.
In Haiti, authorities used social media to alert people about the storm and urged them to evacuate if they lived near water or mountain flanks.
"The whole country is threatened," the Civil Protection Agency said in a statement. "Make every effort to escape before it's too late."
Haiti is especially vulnerable to floods and landslides because of widespread erosion and deforestation. In addition, a recent spike in gang violence has forced thousands of people to flee from their homes, so the civil protection agency is running low on basic items including food and water, director Jerry Chandler told The Associated Press.
"It's been three weeks that we've been supporting families who are running away from gang violence," he said. "We are working at renewing our stocks, but the biggest problem is logistics."
He said officials are still trying to figure out how to deliver supplies to Haiti's southern region, which braced for Elsa's impact.
Meanwhile, people bought water and food before the storm approached.
Elsa was the first hurricane of the Atlantic season and the earliest fifth-named storm on record.