Officials across the Caribbean prepare for days of heavy rain from the storm.

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.

The National Hurricane Center's 5 p.m. Friday update reported that Tropical Storm Melissa is in the Caribbean Sea, 215 miles southeast of Kingston Jamaica and 225 miles southwest of Port Au Prince Haiti. Packing maximum sustained winds of 65 mph, it is tracking north at 2 mph. Melissa is expected to strengthen into a hurricane.