HOUSTON — Hurricane Melissa strengthened into a major Category 4 hurricane, with the possibility of intensifying to a Category 5 storm Sunday night, unleashing torrential rain and threatening to cause catastrophic flooding in the northern Caribbean, including Haiti and Jamaica, the U.S. National Hurricane Center said.

Hurricane Melissa has strengthened into a Category 5 storm as it draws closer to Jamaica, where forecasters say it will unleash catastrophic flooding, landslides and widespread damage