MIAMI, United States (CMC)—A hurricane watch is in effect for Haiti on Wednesday as Tropical Storm Melissa moves slowly across the region, and is expected to bring heavy rainfall and flooding over portions of Hispaniola and Jamaica over the remainder of this week.

The Miami-based National Hurricane Center (NHC) said that the storm could become a hurricane by Thursday and is about 305 miles south-southwest of Port-au-Prince in Haiti and 335 miles southeast of Kingston, the Jamaican capital.

It has maximum sustained winds of 50 miles per hour (MPH), and the NHC said that some gradual strengthening is anticipated during the next few days.

A tropical watch is in effect for Jamaica, and the NHC said that a hurricane watch for Haiti means that hurricane conditions are possible within the area. It said interests in Haiti, the Dominican Republic, and Cuba should monitor the progress of Melissa.

Melissa is moving very slowly towards the west-northwest at near two mph, and the NHC said that a slow forward speed and a gradual turn to the northwest and north-northwest are expected during the next few days.

“On the forecast track, Melissa is expected to approach Jamaica and the southwestern portion of Haiti later this week,” the NHC said, adding that tropical storm conditions could begin in Jamaica late on Thursday or Friday.

Melissa is expected to bring five to 10 inches of rain to the southern Dominican Republic, southern Haiti, and eastern Jamaica through Saturday, with locally higher amounts possible.

“Across the northern Dominican Republic, northern Haiti, and western Jamaica, two to four inches of rain are expected through Saturday,” the NHC added.