COLUMBIA, S.C. — In order for a storm to meet the criteria to be classified as a rapidly intensifying storm, wind speeds must increase by 35 miles per hour within 24 hours.
Idalia ranks as the fourth most extreme rapid intensification ever observed for a storm making landfall in the U.S. The other top storms were Humberto (2007), Ida (2021), and King (1950).
Hurricanes thrive on warm water. When a storm passes over waters above 80 degrees Fahrenheit, it will likely intensify.
Wind shear is the change in wind speed and direction at different altitudes. High wind shear can disrupt a storm's organization, whereas low wind shear allows a hurricane to stay aligned and strengthen faster.
Lastly, a moist atmosphere. When the storm is surrounded by moist air, it can sustain or even intensify its strength.
In recent years, several hurricanes have intensified rapidly, including Florence in 2019, which increased its peak winds from 75 to 140 miles per hour in 24 hours.
According to Climate Central, in the Atlantic, 170 landfalling tropical cyclones have experienced rapid intensification since 1980. When storms intensify so rapidly, emergency management officials have much less time to issue warnings, facilitate evacuations, and ensure resident safety.