Abstract:Analysis and reanalysis datasets derived from numerical models are commonly applied in diagnosing and forecasting weather extremes by using traditional synoptic charts. Recent studies have showed that any atmospheric variable from these datasets can be naturally decomposed into climatic and anomaly based components while the latter can be used to locate regional heavy rains, heat waves and low temperature, and also to indicate the intensity of these extreme weather events. This paper focuses on the analysis of anomaly based variables using different datasets during the lifetime of super Typhoon Megi (2010) because it has been studied recently by several researchers. The inconsistency of typhoon intensity estimated from four meteorological centers in China, Japan and the United States is first analyzed. A hydrostatic balance relationship from both height and temperature anomalies is described from the European Centre for Medium Range Weather Forecasts (ECMWF) re analysis interim reanalysis. The results show that the anomaly based variables can be used in indicating the evolution of typhoon anomalous intensity. This work can provide an useful reference for applying the output products of medium range weather forecast models to the prediction and diagnosis of typhoon intensity.