Hurricane Melissa strengthened into a Category 5 storm early Monday, unleashing torrential rain and threatening to bring catastrophic flooding to the northern Caribbean.

Hurricane Melissa strengthened into a Category 5 hurricane Monday morning and forecasters warn more strengthening is possibe.

Haiti is expected to see catastrophic flash floods and landslides early next week causing “extensive infrastructural damage and potentially prolonged isolation of communities.” The southwestern peninsula of Haiti, from the border of the Dominican Republic to Port-au-Prince, was placed under a hurricane watch and a tropical-storm warning.

The storm's slow movement is expected to bring a deluge of rain to multiple countries in the Caribbean, and prolong its dangerous impacts over a period of several days.

Hurricane Melissa has 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,