Hurricane Erin has strengthened into a Category 2 storm as it approaches Puerto Rico and the Virgin Islands, bringing heavy rains that could cause flooding and landslides.

The first Atlantic hurricane of the season is forecast to bring heavy rain and life-threatening surf and rip currents to the U.S. East Coast this week.

A disturbance in the Atlantic following Hurricane Erin is now expected to track northward, National Hurricane Center data shows.

Storms that ramp up so quickly complicate forecasting and make it harder for government agencies to plan for emergencies. Hurricane Erick, a Pacific storm that made landfall June 19 in Oaxaca, Mexico, also strengthened rapidly, doubling in intensity in less than a day.

Tracking Hurricane Erin, the first named storm of the Atlantic hurricane season, which weakened to a Category 3 storm early Sunday.

The orders have enabled Puerto Rico's government to fix and restore lines and ensure sustained energy resilience.

Hurricane Erin forced tourists to cut their vacations short on North Carolina’s Outer Banks even though the monster storm is expected to stay offshore after lashing part of the Caribbean with rain and wind on Monday.