People in the Azores archipelago were advised Monday to monitor the progress of Hurricane Gabrielle which is now a Category 4 hurricane in the central Atlantic Ocean, the National Hurricane Center said. Gabrielle had maximum sustained winds of 140 mph on Monday afternoon as it skirted to the east-southeast of Bermuda, according to a hurricane center advisory. National Hurricane Center National Hurricane CenterGabrielle had become a Category 1 hurricane on Sunday before it underwent intensification in warm Atlantic waters. Forecasters said the swells were likely to cause “life-threatening surf and rip current conditions.”This year’s Atlantic hurricane season has been relatively quiet and before Gabrielle there was only one named hurricane in that ocean. The Atlantic hurricane season ends Nov. 30.