Tropical Storm Gabrielle strengthened into a hurricane Sunday afternoon southeast of Bermuda in the Atlantic Ocean, forecasters say. The Miami-based National Hurricane Center said Gabrielle’s maximum sustained winds increased to 75 mph (120 kph), making it a Category 1 hurricane. Watch NBC6 free wherever you are WATCH HERE WATCH HEREGabrielle was located about 320 miles (515 kilometers) southeast of Bermuda and moving to the north-northwest at 10 mph (17 kph).