Jamaica and other parts of the Caribbean are staring down what could become a catastrophic, days-long assault of extreme rainfall and damaging winds.

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.

Hurricane Melissa has strengthened into a major Category 4 hurricane, with the possibility of intensifying to a Category 5 storm Sunday night.

FOX Weather Meteorologist Ari Sarsalari breaks down Tropical Storm Melissa as the slow moving storm intensifies in the Caribbean.  Millions of people in Jamaica, Haiti and the Dominican Republic are preparing for flooding rain and high winds as Tropical Storm Melissa,

Tropical Storm Melissa lumbered through the Caribbean Sea on Thursday, bringing a risk of dangerous landslides and life-threatening flooding to Jamaica and southern Hispaniola -- an island shared by the Dominican Republic and Haiti.

The US-based National Hurricane Center (NHC) is monitoring a tropical wave moving over the Windward Islands, according to its 8:00 am bulletin on Sunday. Heavy rainfall and gusty winds are anticipated as it moves across the region,