PORT-AU-PRINCE — Jamaica is staring down what could become a catastrophic, days-long assault of hurricane conditions as Melissa strengthens over some of the hottest ocean water on the planet.

The storm’s outer bands are already brushing Jamaica and western Haiti, where hurricane watches are in effect, meaning hurricane-force winds are possible by the weekend. A tropical storm warning is also in effect for these islands, where officials are urging residents to prepare for power outages, flooding, landslides and dangerous seas.

At least three deaths have been reported in Haiti due to the storm, the Haitian Civil Protection Agency said in a statement.

As of early Friday, Melissa just over 150 miles south-southeast of Kingston, Jamaica, with sustained winds of 45 mph, according to the National Hurricane Center. The storm is hardly moving.

Melissa is expected to rapidly intensify to a Category 4 or stronger hurricane by Sunday, hovering near or over Jamaica with punishing wind and torrential rain through early next week. This explosive strengthening is happening more often as the world warms due to fossil fuel pollution. Three of the four Atlantic hurricanes this season underwent extreme rapid intensification: Erin, Gabrielle and Humberto.

Up to 14 inches of rain could fall, with isolated totals topping a foot across southern Haiti, southern Dominican Republic and eastern Jamaica through early next week. Those totals will likely climb even higher, but by exactly how much depends on Melissa’s track and intensity.

All public hospitals have been in “emergency mode” since Thursday evening, according to Christopher Tufton, Jamaica’s Minister of Health and Wellness. This designation halts outpatient and elective procedures and ensures more beds are open for emergencies.

Jamaica’s airports remain open for now, but will likely close within 24 hours of a hurricane warning being issued for the country, according to Daryl Vaz, Minister of Science, Energy, Telecommunications and Transport.

The United States mainland is not completely out of the woods, but a direct hit looks unlikely. If Melissa takes longer to turn north, it could bend toward eastern Cuba or the Bahamas before curving into the Atlantic. Even so, rough surf and rip currents could spread along the US East Coast next week.

There’s also still a slim chance that Melissa takes a sharp turn to the north earlier than expected and bear down directly on Haiti. That scenario would deliver highly-concentrated impacts there and torrential rain to the Dominican Republic.

As this tricky forecast comes into focus, all signs point to Jamaica being ground zero for what could become one of the most destructive hurricanes of the season. — CNN