Extreme pre-landfall rapid intensification of Typhoon Odette in an unfavorable environment
Abstract
Typhoon (TY) Odette (international name "Rai") was a category 5 typhoon that made landfall in northeastern Mindanao at around 2 pm on December 16, 2021, with maximum 1-min (10-min) sustained winds of 150 kt (105 kt). TY Odette underwent rapid intensification (RI) overnight before landfall from 70 to 150 kt in a 24 h period starting from 00Z of December 15, 2021, calculated to be in the upper 99.9th percentile intensity change for TCs making landfall in the country. This resulted in a large error in the landfall intensity forecast from 85 kt the night before to 140 kt on the morning of landfall day, this led to miscalculated disaster mitigation response and humanitarian efforts making it the 2nd costliest TY in the Philippines. Its RI occurred in an unfavorable environment characterized by a moderate vertical wind shear. Satellite and modeling analysis show the evolution of the TC inner dynamics removed the environmental shear and made itself an environment conducive to its intensification. A confluence of other factors such as sea surface temperature distribution profile and the position of the subtropical jet also aided in enhancing intensification.