From being a tropical storm, Irene is now officially a hurricane as it gained strength early Monday after it began moving across Puerto Rico and threatening to move forward the U.S. later this week.

Earlier, Irene reportedly caused havoc in the U.S. Virgin Islands downing trees and power outages, according to reports.

Forecasters said the storm is passing directly over the island of Puerto Rico with initial speed of 70 mph (110 kph). It’s center was about 25 miles (40 kilometers) west of San Juan.

In the U.S., Irene is set to become the first hurricane of the Atlantic hurricane seasion, expected to affect Florida, Georgia, and North/South Carolinas.