Hurricane Erin weakened to a Category 3 storm with maximum sustained winds of 125 mph as its outer bands pounded the Virgin Islands and Puerto Rico with gusty winds and heavy rains early Sunday.

Powerful Hurricane Erin has undergone a period of astonishingly rapid intensification — a phenomenon that has become far more common in recent years as the planet warms. It was a rare Category 5 for a time Saturday before becoming a Category 4,

Erin has become the first hurricane of the Atlantic season with strong waves and rip currents possible along the East Coast of the United States as early as next week.

U.S. shores are unlikely to see a direct hit, but a strong offshore hurricane can produce massive and dangerous waves well away from its center.

Over the weekend, northern portions of the Leeward Islands, the Virgin Islands, and Puerto Rico are expected to receive tropical rain ranging from 2 to 4 inches, with isolated totals up to 6 inches. Flash flooding, landslides and mudslides will be the main concerns over the next several days.

Hurricane Erin intensified from Category 3 to Cat 5 in just a couple of hours. Though not expected to make landfall, Erin will create dangerous rip currents next week.

Reports from NOAA and Air Force Reserve Hurricane Hunter aircraft indicate that maximum sustained winds have increased to near 75 mph. Steady to rapid strengthening is expected during the next two to three days, and Erin is forecast to become a major hurricane this weekend.

The NHC said it currently expected Erin to become a Category 4 storm later Saturday but to eventually swerve away from the continental United States.

Hurricane Erin is forecast to remain well offshore but still bring hazardous currents and possible erosion like previous offshore hurricanes before it.