A Simple Empirical Model for Estimating the Intensity Change of Tropical Cyclones after Landfall along the South China Coast

Abstract

The intensity change of past (1976?2005) tropical cyclones that made landfall along the south China coast (110.5°?117.5°E) is examined in this study using the best-track data from the Hong Kong Observatory. The change in the central pressure deficit (environmental pressure minus central pressure) and maximum surface wind after landfall are found to fit fairly well with an exponential decay model. Of the various potential predictors, the landfall intensity, landward speed, and excess of 850-hPa moist static energy have significant influence on the decay rates. Prediction equations for the exponential decay constants are developed based on these predictors.