(CNN) -- Just hours after being designated a hurricane, Ophelia was intensifying Thursday evening in the Atlantic Ocean and was forecast to strengthen even more in the coming days, the National Hurricane Center said.
The system had appeared to be weakening several days ago, only to emerge from tropical storm status Thursday.
As of 8 p.m. ET, Ophelia was about 770 miles south-southeast of Bermuda. It was heading north-northwest at seven miles an hour, the Miami-based center said.
Ophelia is a Category One storm with maximum sustained winds of 80 mph. Hurricane-force winds extended about 25 miles from its eye.
Tropical storm-force winds have been recorded 175 miles away, the center said.
Starting late Saturday, Ophelia could affect Bermuda in the mid-Atlantic, where a tropical storm watch is now in effect. But the hurricane, which is likely to gradually turn north and speed up Friday, is not expected to make a significant impact on the U.S. coast.
Meanwhile, Tropical Storm Philippe was churning farther east in the Atlantic, with its eye some 1,210 miles east-northeast of the Leeward Islands.
There has been no significant change in Philippe's strength over the past 48 hours, the hurricane center said late Thursday afternoon, but it added that "some strengthening is possible." It had maximum sustained winds of 45 mph.
Philippe was heading northwest at around 13 mph, with a shift to the west-northwest forecast for Friday night and Saturday. No land areas have been affected or are in the storm's path through the forecast period, which now extends into Tuesday afternoon.