Evolution of Tropical Cyclone Fullness and Intensity in Concentric Eyewall Formation: A Statistical Analysis

Abstract Understanding the relationship between tropical cyclones (TCs) wind structure and intensity is essential for improving intensity forcasts. This study analyzes a long‐term global data set of concentric eyewall (CE) TCs to examine the temporal evolution of TC fullness (TCF) and intensity preceding second eyewall formation (SEF). Results show that over 99% of CE TCs exhibit TCF exceeding 0.7 at SEF onset, with approximately 95.74% undergoing rapid intensification. Notably, 73% of CE TCs experience rapid changes in TCF, and 24% experience rapid changes in both TCF and intensity. Higher TCF, greater intensity, and more favorable environmental conditions increase the likelyhood of rapid changes in TCF followed by rapid changes in intensity. Furthermore, the lead time of rapid TCF changes is negatively correlated with TCF and intensity themseves. These findings offer novel insights into TC intensity evolution during CE development.