Melissa has already been blamed for three deaths in Haiti this week, as its outer bands brought heavy rains and landslides to the impoverished nation.

In the Dominican Republic, which shares the island of Hispaniola with Haiti, a 79-year-old man was found dead after being swept away in a stream, local officials said Saturday. A 13-year-old boy was missing.

"You feel powerless, unable to do anything, just run away and leave everything behind," Angelita Francisco, a 66-year-old homemaker who fled her neighborhood in the Dominican Republic, told AFP through tears.

Floodwater had inundated her house, causing her refrigerator to float away as trash bobbed around the home.

The US National Hurricane Center (NHC) said on Sunday that Melissa had intensified into a Category 4 hurricane, packing winds of about 140 miles (225 kilometers) per hour and moving at 5 mph.

The storm was expected to set off "life-threatening and catastrophic" flooding and landslides in parts of Jamaica and southern Hispaniola, the NHC said, forecasting "continued rapid intensification... followed by fluctuations in intensity."

Melissa was "expected to be a major hurricane when making landfall in Jamaica Monday night or Tuesday morning, and southeastern Cuba late Tuesday," it added.

As of Sunday, Melissa was about 120 miles (around 190 kilometers) southeast of Jamaica's capital Kingston, and 280 miles (450 kilometers) southwest of Guantanamo, Cuba.

The Dominican Republic's emergency operations center said nine of 31 provinces were on red alert Saturday due to risk of flash floods, rising rivers and landslides.

Melissa could bring 15 to 30 inches (38 to 76 cm) of rain in portions of southern Hispaniola and Jamaica, with isolated areas expected to receive as much as 40 inches, the NHC said.

Jamaican Prime Minister Andrew Holness on Friday urged residents of flood-prone areas to heed warnings and be prepared to evacuate.

"If you live in an area that was flooded before, expect that it will flood again," he said.

Norman Manley International Airport, which serves Kingston, announced it would close on Saturday evening and urged the public not to travel there.

The Jamaica Information Service government agency said on Saturday that all seaports had been closed.

Melissa is the 13th named storm of the Atlantic hurricane season, which runs from early June to late November.

The last major hurricane to impact Jamaica was Beryl in early July 2024 -- an abnormally strong storm for the time of year.

Beryl brought downpours and strong winds to Jamaica as it moved past the island's southern coast, leaving at least four people dead.