Updated

A weakening Tropical Storm Danny swirled toward the U.S. Virgin Islands and Puerto Rico, where a prolonged drought has led to hopes that it would bring rain.

But forecasters said the storm would become a tropical depression before reaching Puerto Rico and bring little relief to the U.S. territory.

Late Saturday night, Danny was located 480 miles (775 kilometers) east of the Leeward Islands, with maximum sustained winds of 60 mph (95 kph), according to the U.S. National Hurricane Center. It was traveling west at 15 mph (24 kph).

The hurricane center said it expected Danny to be near the Leeward Islands by Sunday night or Monday morning, and reach Puerto Rico early Tuesday.

"The biggest threats to land are the northern Leeward Islands, the Virgin Islands, Puerto Rico and Hispaniola," said hurricane center specialist Robbie Berg.

Meteorologists said it was too early to predict how much rainfall Danny would generate over Puerto Rico, which has implemented extreme water-rationing measures since May as it struggles with one of the worst droughts in its history.

"This storm has created a lot of expectations," said Carlos Anselmi with the National Weather Service in San Juan. "But we cannot talk about how much rainfall is expected because the storm is quite small. There's a lot of uncertainty still."

The news was disheartening for Puerto Rico residents such as 88-year-old Gloria Rodriguez, who has struggled with water-rationing measures in which hundreds of thousands of people receive water only twice a week.

"We're asking God to bring us water and not destruction," she said. "This is what we're all hoping for."

Nearly 25 percent of Puerto Rico is considered to be in an extreme drought, and another 45 percent is under a severe one, according to The National Drought Mitigation Center. A total of 2.9 million people in Puerto Rico have been affected, and U.S. officials have declared at least 20 of the island's 78 municipalities as disaster zones.

Anselmi said Danny was expected to dump more rain over the U.S. Virgin Islands than Puerto Rico.

U.S. Virgin Islands Gov. Kenneth Mapp said officials were distributing sandbags and had opened shelters as a precaution.

The approaching storm forced Antigua-based airline LIAT to cancel nearly 40 flights from Sunday to Tuesday, and officials with regional carrier Seaborne Airlines also warned of delays and cancelations. Several cruise ships scheduled to visit the U.S. Virgin Islands have canceled or delayed their trips.

A tropical storm watch was in effect for Antigua, Barbuda, St. Kitts, Nevis, Montserrat, Anguilla, St. Maarten, Saba, St. Eustatius, Guadeloupe, St. Barthelemy and St. Martin.

___

Danica Coto on Twitter: www.twitter.com/danicacoto