KINGSTON, Jamaica — Hurricane Melissa has intensified into a major Category 4 storm, with the potential to reach Category 5 status by Sunday night. The U.S. National Hurricane Center warns that the hurricane is unleashing heavy rainfall and poses a significant risk of catastrophic flooding in the northern Caribbean, particularly in Haiti and Jamaica.

The hurricane is expected to approach the southern coast of Jamaica late Monday or early Tuesday. Jamaican Prime Minister Andrew Holness urged residents to take the threat seriously, stating, "I urge Jamaicans to take this weather threat seriously. Take all measures to protect yourself."

As of Sunday morning, Melissa was located about 120 miles (195 kilometers) south-southeast of Kingston and approximately 280 miles (450 kilometers) south-southwest of Guantanamo, Cuba. The storm has maximum sustained winds of 140 mph (225 kph) and is moving west at 5 mph (8 kph).

The hurricane is forecasted to bring torrential rains of up to 30 inches (760 millimeters) to Jamaica and southern Hispaniola, which includes Haiti and the Dominican Republic. Some areas may experience as much as 40 inches (1,010 millimeters) of rain. The hurricane center has warned of extensive damage to infrastructure, power outages, and the isolation of communities in Jamaica.

By late Tuesday, Melissa is expected to be near or over Cuba, where it could deliver up to 12 inches (300 millimeters) of rain before moving toward the Bahamas on Wednesday. In anticipation of the storm, the Cuban government issued a hurricane watch for the provinces of Granma, Santiago de Cuba, Guantanamo, and Holguin.

The slow-moving storm has already resulted in fatalities, with at least three people reported dead in Haiti and one in the Dominican Republic. Another person is missing in the Dominican Republic. Jamie Rhome, deputy director of the hurricane center, noted, "Unfortunately for places along the projected path of this storm, it is increasingly dire."

Authorities in Jamaica announced that Norman Manley International Airport in Kingston will close at 8 p.m. local time. The status of Sangster Airport in Montego Bay remains unclear. More than 650 shelters have been activated across Jamaica, and officials have prepared warehouses with food packages for quick distribution if necessary.

In Haiti, authorities reported three deaths linked to the hurricane and five injuries from a collapsed wall. Rising river levels have caused flooding and destroyed a bridge in Sainte-Suzanne, located in the northeast. Ronald Délice, a director of civil protection in Haiti, expressed concern about the storm's movement, stating, "The storm is causing a lot of concern with the way it’s moving."

In the Dominican Republic, nearly 200 homes have been damaged, and water supply systems have been disrupted, affecting over half a million customers. The storm has also downed trees and traffic lights, caused small landslides, and isolated more than two dozen communities due to flooding.

The Bahamas Department of Meteorology has warned that Melissa could bring tropical storm or hurricane conditions to the Southeast and Central Bahamas and the Turks and Caicos Islands by early next week. Melissa is the 13th named storm of the Atlantic hurricane season, which runs from June 1 to November 30. The National Oceanic and Atmospheric Administration has predicted an above-normal season with 13 to 18 named storms.