Melissa is a relatively slow-moving Category 4 major hurricane—a brutal combination that will drench some parts of Jamaica with up to 40 inches of rain

K INGSTON, Jamaica — 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.

An extremely dangerous and unnerving scenario will unfold tonight, tomorrow and Tuesday across the eastern half of Jamaica, including the capital, Kingston.

U.S. forecasters issued a hurricane warning for Jamaica on Saturday as Tropical Storm Melissa reached hurricane strength, threatening catastrophic flooding in the northern Caribbean.

Tropical Storm Melissa is expected to become a major hurricane over the weekend. The storm is currently located in the Caribbean and is not expected to directly hit Florida. Jamaica and Haiti are under hurricane and tropical storm watches and warnings.