Tropical Storm Irene, which is the ninth storm for the 2011 Atlantic hurricane season, formed on Saturday east of the Caribbean's Leeward Islands.

Irene was heading westward, according to the U.S. National Hurricane Center. As of 7 p.m., Irene was carrying approximately 50 miles per hour (85 kph) winds and was located about 190 miles (305 km) east of Dominica, according to the hurricane center.

Irene's is forcasted to pass near or over Puerto Rico and Hispaniola, which is a share island between the Dominican Republic and Haiti. The storm could be over the Florida Keys by late next week, forecasters said and could develop into the first hurricane of the 2011 Atlantic season.

Irene could pose a threat to the United States or U.S. oil and gas installations in the Gulf of Mexico, depending on the path it takes, but forecasters told Reuters that it is too early to predict at this stage.