Tropical Storm Danny neared the Leeward Islands early Monday and was expected to weaken into a tropical depression.

The center of the storm was located about 100 miles (160 kilometers) east of Dominica late Sunday night. It was moving toward the west at 15 mph (24 kph) with maximum sustained winds near 40 mph (65 kph.

The National Hurricane Center in Miami said Danny will move over the southern Leeward Islands early Monday and then into the northeastern Caribbean Sea. It said the weakening storm is expected to become a tropical depression on Monday and a "remnant low" on Monday night or Tuesday.

Danny is expected to drop 2 to 4 inches of rain over the Leeward Islands, the U.S. And British Virgin Islands, and Puerto Rico through Tuesday.

Forecasters said the storm would likely bring little relief to drought-stricken Puerto Rico.

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.

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.