Hurricane Ethel originated from a small tropical disturbance over the Gulf of Mexico on the morning of September 14, 1960. It is estimated that Ethel developed into a tropical storm at 1200 UTC on that day, with an initial intensity of 45 mph (75 km/h). The disturbance quickly developed within a region favoring intensification and the New Orleans Hurricane Warning Office issued their first advisory on the system, classifying it as an area of low pressure, at 1500 UTC. Roughly six hours after becoming a tropical storm, Ethel was upgraded to a hurricane as it underwent an intense phase of explosive deepening. By this time, gale-force winds extended 150 miles (240 km) to the north of the center and 80 miles (130 km) to the south. Ethel further intensified into a major hurricane, as it approached the Gulf Coast of the United States.