How many hours did the storm which surpassed Typhoon Nora in 2015, grow from a tropical storm to a Category 5 hurricane?
Typhoon Nora (1973) Typhoon Nora was the fourth-most intense tropical cyclone on record. Originating from an area of low pressure over the western Pacific, Nora was first identified as a tropical depression on October 2, 1973. Tracking generally westward, the system gradually intensified, attaining typhoon status the following evening. After turning northwestward, the typhoon underwent a period of rapid intensification, during which its central pressure decreased by 77 mb (hPa; 2.27 inHg) in 24 hours. At the end of this phase, Nora peaked with winds of 295 km/h (185 mph) and a pressure of 877 mb (hPa; 25.91 inHg), making it the most-intense tropical cyclone on record (alongside Typhoon Ida in 1958) at the time; however, this pressure has since been surpassed by two other typhoons and one hurricane. The typhoon subsequently weakened and turned northwestward as it approached the Philippines. After brushing Luzon on October 7, the system passed south of Taiwan and ultimately made landfall in China on October 10. Once onshore, Nora quickly weakened and dissipated the following day.
Typhoon Ophelia Typhoon Ophelia was a long-lived and powerful tropical cyclone that had devastating impacts on the small atoll of Ulithi in the Caroline Islands. Forming as a tropical depression on November 21, 1960 near Enewetak Atoll, the incipient cyclone struggled to develop. Moving haphazardly along an s-shaped track over the western Pacific Ocean, it degenerated into a disturbance two days later. By November 27, the system reorganized and was classified a tropical depression for a second time well to the southeast of Guam. Moving slowly west-southwest, it steadily intensified into a tropical storm later that day and further into a typhoon on November 29 as it gained a steady westward track. The following day, the eye of Ophelia passed directly over Ulithi atoll with winds estimated at 230 km/h (145 mph).