MIAMI — Tropical storm watches were issued for various Caribbean islands Monday evening for what soon could become the sixth named tropical storm of this year’s Atlantic hurricane season.

Watches were in effect for Martinique, Guadeloupe, Dominica, Puerto Rico, the U.S. Virgin Islands and the Dominican Republic, according to a 5 p.m. advisory from the National Hurricane Center. A tropical storm watch means that tropical storm conditions are possible within the watch area.

Forecasters believe the disturbance heading toward the Lesser Antilles could become Tropical Storm Fred later Monday night. It has been more than a month since this year’s fifth named storm — Hurricane Elsa — formed.

The disturbance had maximum sustained winds of 35 mph (55 kmh) with higher gusts and was 165 miles (260 kilometers) east-southeast of Dominica, according to officials. A tropical storm has maximum sustained winds of at least 39 mph (63 kmh). It was moving west-northwest at 15 mph (24 kmh).

The storm is forecast to move through a portion of the southern Leeward Islands Monday night, pass near or over the U.S. Virgin Islands and Puerto Rico late Tuesday and Tuesday night, and near or over Hispaniola on Wednesday.

The storm is expected to produce rainfall totals of 2 to 4 inches (5 to 10 centimeters) over the Leeward Islands, Virgin Islands, and Puerto Rico, with up to 6 inches (15 centimeters) in some areas. The rainfall could lead to flash, urban, and small-stream flooding and potential mudslides across the U.S. Virgin Islands and Puerto Rico.