Tropical Storm Melissa neared hurricane strength Saturday and was expected to rapidly intensify this weekend, as forecasters warned of massive rainfall and life-threatening flooding and landslides in the northern Caribbean.

At 8 a.m. Saturday, the National Hurricane Center issued an advisory stating that Tropical Storm Melissa is in the Caribbean Sea, 160 miles southeast of Kingston Jamaica and 235 miles southwest of Port Au Prince Haiti. The system, with maximum sustained winds of 70 mph, is moving west-northwest at 1 mph.

The storm is expected to hit Jamaica, Haiti and the Dominican Republic, as well as Cuba, the Bahamas, and the Turks and Caicos.

Melissa is currently the only active tropical system in the Atlantic basin. As of Friday night, the storm remains nearly stationary, drifting north at just 2 mph. Maximum sustained winds are around 65 mph—just below the 75 mph threshold needed to reach Category 1 hurricane status.

Tropical Storm Melissa is nearly stationary in the central Caribbean, with forecasters warning it could soon strengthen and brush past Jamaica as a powerful hurricane.