The sixth named storm of the Atlantic hurricane season formed Wednesday afternoon, and the US National Hurricane Center issued tropical storm watches for the easternmost Caribbean islands. “Interests in the Leeward Islands, the Virgin Islands and Puerto Rico should monitor the progress of this system,” the center said. At 8 a.m. EDT Thursday, Fiona was moving at 13 mph (20 km/h) with maximum sustained winds of about 50 mph (85 km/h), forecasters said. A small power change is expected in the coming days. Fiona was located about 545 miles (875 km) east of the Leeward Islands and tropical storm watches were issued for Saba and St. . Fiona is expected to produce total rainfall of 3 to 6 inches with isolated higher amounts over the northern Leeward Islands, British Virgin Islands and the US, Puerto Rico and eastern Hispaniola. Oceans should begin to affect the northern Leeward Islands by early Friday, causing life-threatening surf and rip currents.