Miami ? Helene became a hurricane again Saturday as it moved quickly over the open Atlantic, and the storm will likely create hazardous surf conditions for Bermuda, forecasters said.

Helene’s top sustained winds strengthened to 90 mph, above the 74 mph threshold to be classified as a hurricane, the National Hurricane Center in Miami said in a special advisory. Helene had been downgraded to a tropical storm with winds of 70 mph Friday night.

However, Helene was expected to weaken as it gradually loses tropical characteristics, the hurricane center said.

Tropical-storm-force winds of at least 39 mph extend up to 345 miles from Helene’s center.