KINGSTON, Jamaica (AP) – 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.

The weather agency added Melissa is likely to reach the southern coast of Jamaica Tuesday morning and urged Jamaicans to seek shelter now.

It should be near or over Cuba by late Tuesday before moving toward the Bahamas later Wednesday.

The erratic and slow-moving storm has killed at least three people in Haiti and a fourth person in the Dominican Republic, where another person remains missing.