LAUSR

In this paper, diurnal variations in tropical cyclone (TC) intensification and decay over the ocean are considered for the global TC basins from 1982–2017 using best track data. Statistically significant diurnal variations are found for global TCs, with a maximum intensification over the period 03–09 local solar time (LST). No diurnal signals are detected for TC decay. The highest frequency of occurrence and highest rate of intensification at 03–09 LST for global TCs are associated with the largest coverage of the very deep convective clouds with IR BT < 208 K at 03–06 LST. TC vortex spin‐up is favored at early morning through diurnal circulation linked to very deep convection.