On September 15, 1960, Hurricane Ethel became a Category Five hurricane in the Gulf of Mexico, becoming the most northerly hurricane to reach this maximum status on record.
Hurricane Ethel formed from a disturbance in the central Gulf just as Hurricane Donna was dying out over the Labrador Sea. As the storm moved northward, it underwent a very rapid intensification. Within six hours of detection, Ethel was found to be a full hurricane. Within another six hours it was a major hurricane. By the early morning of the 15th, a Navy Hurricane Hunter found winds of 160 mph (260 km/hr). At this time the center was fixed at 28.10 degrees North latitude, the furthest north a hurricane had ever reached this intensity.
But as rapidly as Hurricane Ethel spun up, it spun down even faster. By the next reconnaissance flight, Ethel was back to being a minimal hurricane with winds of 90mph (150 km/hr). Luckily, Ethel brushed the Louisiana coast with just hurricane-force winds and when it made landfall on the Mississippi coast it was just a tropical storm with 70 mph (110 km/hr) maximum sustained winds. Ethel continued to weaken as it moved inland and eventually dissipated over Kentucky. Only one indirect death is attributed to Ethel and it managed only US$1.5 million in damage, mostly in coastal areas.
There is doubt about Ethel’s actually reaching Category Five status, since the central pressure measured by the Navy plane (972 mb) was very high for the accompanying wind estimate. Ethel is now undergoing re-evaluation as part of the HURDAT reanalysis.
Paper using Ethel information by NHRL scientists:
Colon, J. A., and W. R. Nightingale, 1963: Development of tropical cyclones in relation to circulation patterns at the 200-millibar level. Mon. Wea. Rev., 91, 329-336.