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.

Additional strengthening is expected as the storm is forecast to “remain a large and dangerous major hurricane through the middle of this week,” the National Hurricane Center said.

While the category 4 storm is not expected to make landfall on the U.S. east coast, it will have an impact nonetheless. Dangerous high surf and rip currents are expected from Florida to New England throughout the week.

Hurricane Erin has been downgraded to a Category 3 hurricane but is gaining in size and raising the risk of life-threatening surf later this week along the U.S.

Most of Erin’s intensification occurred during a 12- to 15-hour window overnight, according to Dan Pydynowski, a meteorologist at AccuWeather. By 5 p.m. Friday, Erin’s winds had remained only 75 mph.

Dangerous coastal impacts from Hurricane Erin will peak along the East Coast on Wednesday and Thursday as the storm passes offshore.