Do Tropical Cyclone Outer Size Forecasts Improve Simultaneously With Intensity Forecasts?

Abstract The outer size of a tropical cyclone (TC) is important for predicting potential damage caused by the storm, yet improving the size forecast remains challenging. This study evaluates the TC intensity and outer size forecast performance of five numerical models from the National Oceanic and Atmospheric Administration (NOAA) based on 15 representative North Atlantic hurricanes from 2020 to 2022. We found there is little correlation between TC intensity and outer size forecast accuracy. Higher‐resolution models outperform coarser‐resolution models in intensity prediction but perform similarly for outer size regardless of resolution. Notably, the initial storm outer size may significantly influence the outer size forecast: initially larger storms may present greater challenges for accurate size prediction. Our results provide new insights into the complex relationship between TC size and intensity forecasting, highlighting the need to understand how environmental factors affect size forecasts and their connection to model resolution and configuration.