(NewsNation) — Hurricane Erin, the first Atlantic hurricane of 2025, has rapidly strengthened into a Category 5 from a tropical storm in a single day on Saturday.

With maximum winds of 160 mph, Erin is a “catastrophic” hurricane in the Caribbean, though it is not expected to hit land, the National Weather Service reported.

The hurricane remained a Category 5 storm Saturday evening, when it was located 135 miles (220 kilometers) northwest of Anguilla and moving west at 15 mph (24 kph). The storm’s center was forecast to remain at sea, passing 145 miles (233 kilometers) north of Puerto Rico, according to the National Hurricane Center.

Tropical storm watches were issued for St. Martin, St. Barts and St. Maarten. The Hurricane Center warned that heavy rain in some areas could trigger flash flooding, landslides and mudslides.

Although the hurricane eye is forecast to remain far offshore, the United States East Coast may withstand powerful rip currents.

Erin rapidly grew from a Category 2 to a 5 within nine hours, becoming a “very powerful hurricane,” said Mike Brennen, director of the National Hurricane Center in Miami, in an online briefing.

The Atlantic hurricane season runs from June 1 to Nov. 30, and Erin is the first of five named storms to become a hurricane.

The Associated Press contributed to this report.