Beryl weakened to a tropical storm Saturday but is still expected to dump heavy rain over the Lesser Antilles at the end of the weekend on its way to the eastern Caribbean, bringing a new threat to islands still rebuilding from last year’s storms. A tropical storm warning was issued for Dominica, which was battered by Hurricane Maria in September as a Category 5 storm, and Guadeloupe.

The island’s meteorological service said weather conditions would start deteriorating Saturday night and warned of six to 12 inches of rain, with the storm expected to cross over or near Dominica late Sunday or early Monday.

Beryl was the first named hurricane of the Atlantic season Friday. The National Weather Service said late Saturday that the storm was moving at west-northwest at 18 mph, and was expected to hit the eastern boundary of the Caribbean Sunday. Maximum sustained winds have decreased to 45 mph, and additional weakening is predicted over the next 48 hours.

A tropical storm watch was issued for the French Caribbean territories of Martinique, Guadeloupe, St. Martin and St. Barts as well as the islands of Barbados, St. Lucia, Saba and St. Eustatius. Deeper into the Caribbean, a state of emergency was declared in Puerto Rico, where Maria caused more than an estimated $100 billion in damage.

Forecasters said Beryl is expected to weaken further after entering the Caribbean. It was expected to pass about 70 miles south of Puerto Rico on Monday, but forecasters warned the storm-wracked U.S. territory could see up to 30-mph winds and heavy rains that could cause flooding and mudslides.

Forecasters said Beryl probably would dissipate once it moved south of Haiti and the Dominican Republic on Tuesday or Wednesday.

Meanwhile, Tropical Storm Chris formed in the Atlantic well off the North Carolina coast. The hurricane center said Chris would continue strengthening over the next few days as it tracks northeast off the coast.