Miami ? Hurricane Bill remained energized by warm Atlantic waters late Thursday, with forecasters predicting it would cause significant flooding along the Bermuda coastlines over the next two days.

Bermuda issued a tropical storm warning with the Category 3 hurricane’s top winds continuing to whip at 125 mph. Dangerous waves and riptides were likely along most of the eastern U.S. coast over the weekend and forecasters warned it could return to Category 4 strength by today as it feeds on warm waters. The stronger designation comes from winds that exceed 130 mph.

“It’s moving over waters of 84, 85 degrees Fahrenheit, which could provide some fuel to it. We still think it could restrengthen back into a Category 4. The environmental conditions appear to be right,” said Eric Blake, a hurricane specialist at the National Hurricane Center.