Dependence of tropical cyclone intrinsic intensity variability on the large‐scale environment

Abstract

AbstractThis study examines the dependence of tropical cyclone (TC) intrinsic intensity variability on the large‐scale environment. Using idealized simulations with the Hurricane Research and Forecasting (HWRF) model, the growth of TC intensity errors and the subsequent saturation of intensity errors at the mature stage are quantified for a range of environmental conditions. Among several factors, it is found that sea‐surface temperature (SST) and tropospheric static stability are the two main ones affecting the growth rate and saturation of TC intensity errors, with a larger error saturation at maximum intensity equilibrium and a faster error growth rate during rapid intensification for a warmer SST or less stable troposphere. Results from this study highlight the fundamental characteristics of TC intensity predictability, which appears to vary with environmental conditions, instead of being a universal measure for TCs in all ocean basins. These results also suggest a limit on TC intensity forecast accuracy that is governed by the large‐scale environment, which needs to be taken into consideration for future TC model development.