Tropical Storm Rafael strengthened into a Category 1 hurricane on Tuesday as it swirled past the Cayman Islands and chugged toward western Cuba.

It was another stroke of bad news for Cuba, which has been struggling with blackouts while recovering from another hurricane two weeks ago that killed at least six people in the eastern part of the island.

The storm was located 20 miles (35 kilometers) southeast of Little Cayman in the Cayman Islands on Tuesday morning. It had maximum sustained winds of 75 mph (120 kph) and was moving northwest at 15 mph (24 kph), according to the National Hurricane Center in Miami.

Forecasters warned that Rafael was expected to slam into Cuba on Wednesday after dumping rain on Jamaica and the Cayman Islands on Tuesday. The center warned of floods, storm surges and mudslides.

The U.S. State Department issued an advisory for Cuba on Tuesday afternoon, offering departure flights to non-essential staff and American citizens, and advising others to “reconsider travel to Cuba due to the potential impact of Tropical Storm Rafael.”

On Tuesday morning, the Cuban Civil Defense called on Cubans to prepare as soon as possible, because when the storm makes landfall “it’s important to stay where you are.” The day before, authorities said they had issued an evacuation order for 37,000 people in far eastern Cuba, in the province of Guantanamo, due to bad weather.

A hurricane warning was in effect Tuesday for the Cayman Islands and the Cuban provinces of Pinar del Rio, Artemisa, La Habana, Mayabeque, Matanzas and the Isle of Youth.

A tropical storm warning was in effect for the Cuban provinces of Villa Clara, Cienfuegos, Sancti Spiritus and Ciego de Avila, as well as the lower and middle Florida Keys from Key West to west of the Channel 5 Bridge, and Dry Tortugas. The warning was lifted in Jamaica after the storm passed by the western coast. A tropical storm watch was in effect for the Cuban provinces of Camaguey and Las Tunas.

Officials in the Cayman Islands closed schools and government offices as they urged residents to prepare. Long lines were reported at grocery stores as the storm approached.

Forecasters warned Rafael would unleash heavy rains across the western Caribbean that could lead to flooding and mudslides in parts of Cuba and the Cayman Islands.

Heavy rainfall also was expected to spread north into Florida and nearby areas of the southeast U.S. during the middle to late part of the week. The Hurricane Center predicted storm surges in Florida could reach 1 to 3 feet in Dry Tortugas and 1 to 2 feet in the Lower Florida Keys. A few tornadoes also were expected Wednesday over the Keys and southwestern Florida.

Rafael is the 17th named storm of the season.

The National Oceanic and Atmospheric Administration predicted the 2024 hurricane season was likely to be well above average, with between 17 and 25 named storms. The forecast called for as many as 13 hurricanes and four major hurricanes.

An average Atlantic hurricane season produces 14 named storms, seven of them hurricanes and three major hurricanes.