Hurricane Irene has strengthened over Puerto Rico, becoming the first hurricane of the 2011 Atlantic Season, the U.S. National Hurricane Center (NHC) said in a statement on Monday.

“Preliminary reports indicate that widespread tree and powerline damage has occurred in Puerto Rico,” NHC said.

More than 800,000 homes are without power on the island and Irene has maximum sustained winds of 75 miles per hour (120 kilometers per hour).

“FAA Doppler weather radar indicates winds to near major hurricane strength are now occurring in the higher elevations of the interior mountainous regions of Puerto Rico.”

The NHC said that by 72 hours, the hurricane Irene is expected to move northwestward, east of Florida on the U.S. East Coast and through the Bahamas. The expected maximum sustained wind will be 90 miles per hour on August 25.

Earlier this month, National Oceanic and Atmospheric Administration's (NOAA) Climate Prediction Center (CPC) predicted an active and stormier hurricane season in 2011 with three to five major hurricanes likely to occur in the Atlantic Basin.

According to CPC, five tropical storms – Arlene, Bret, Cindy, Don, and Emily, have formed in the basin this season. Irene is the first hurricane of the season in the Atlantic hurricane region that includes the North Atlantic Ocean, the Caribbean Sea, and the Gulf of Mexico.

Hurricane

Hurricane Irene has strengthened over Puerto Rico, becoming the first hurricane of the 2011 Atlantic Season. PHOTO: The U.S. National Hurricane Center