SAN JUAN, Puerto Rico (AP) — Tropical Storm Melissa was nearly stationary in the central Caribbean on Friday as forecasters warned it could strengthen and swipe Jamaica as a powerful hurricane and dump a staggering amount of rain — up to 35 inches (89 centimeters) — on southwest Haiti, where they warned of catastrophic flooding and landslides.

The erratic storm was expected to drop copious rain on Jamaica and the southern regions of Haiti and the Dominican Republic. At least three people were killed in Haiti, and one person was killed and one reported missing in Dominican Republic.

“These heavy rains are just going to sit over one area for several days,” said Jamie Rhome, deputy director at the U.S. National Hurricane Center.

The storm was located about 190 miles (310 kilometers) southeast of Kingston, Jamaica, and about 225 miles (360 kilometers) southwest of Port-au-Prince, Haiti. It had maximum sustained winds of 65 mph (100 kph) and was moving north at 2 mph (4 kph), the U.S. center said.

A hurricane watch and a tropical storm warning were in effect for Jamaica and Haiti’s southwest peninsula.