Jamaica buckled down Sunday as Tropical Storm Ernesto barreled past it toward Belize and Mexico's Yucatan Peninsula, US forecasters said. At 2100 GMT, the eye of the storm was located about 355 kilometers (220 miles) south of Kingston, with Ernesto expected to dump up to 10 centimeters (4 inches) on the vacation hotspot as it moves south of the island, according to the Miami-based National Hurricane Center. With top winds of 85 kilometers per hour (50 miles per hour), Ernesto was moving westward at 32 kilometers per hour (20 miles per hour). "Tropical storm conditions are expected in Jamaica through this evening," the NHC said. Later Sunday, it was expected to pass south of the Cayman Islands -- where a tropical storm watch was in effect for Grand Cayman Island -- tonight and early Monday. Parts of the Honduran coast were also under a tropical storm watch. In the Dominican Republic, authorities were on the alert for flash floods and landslides. Late Saturday, heavy downpours had caused some flooding in the capital Santo Domingo. A forecast model showed that the storm was not expected to become a hurricane until Friday but some strengthening was expected as it moves over the western Caribbean Sea Monday and Tuesday, forecasters said. "Belize and the Yucatan Peninsula of Mexico should monitor the progress of Ernesto," the NHC warned. The current forecast model has Ernesto brushing the northern coast of Honduras and parts of Nicaragua, then appearing to hit Belize and parts of Guatemala before passing over the Mexican state of Quintana Roo, home to the busy beach resort city of Cancun, on Wednesday. Further east, Tropical Storm Florence -- the sixth named storm of the Atlantic season -- had top winds of 31 kilometers per hour (50 miles per hour) as it headed westward at 22 kilometers per hour (14 miles per hour).