Nation ‘Rapid intensification’: How Idalia could quickly become a major hurricane before landfall August 28, 2023Doyle Rice and Dinah Voyles Pulver, USA TODAYComments Off on ‘Rapid intensification’: How Idalia could quickly become a major hurricane before landfall Rapid intensification is a process in which a storm undergoes accelerated growth by at least 35 mph in a 24-hour period.