Tropical cyclone track characteristics as a function of large-scale circulation anomalies

Abstract

A compositing technique is used to define anomalous 700-mb large-scale circulations that exist during the formation of tropical cyclones that subsequently follow either a straight track or one of the two types of recurving tracks. Anomalous circulations associated with extended periods that do not contain any tropical cyclones are also identified. Physically and statistically different anomalous large-scale circulation patterns exist at the time of genesis for storms following each track type and for inactive periods. The track-type climatology is used to predict the subsequent track type based only on genesis location. In a second scheme the distributions of anomalous 700-mb zonal wind components in 5° latitude bands averaged between 100° and 140°E are used to predict the most likely track type. The large-scale 700-mb anomalies at genesis time determine the subsequent track type in a majority of cases. The skill of this simple scheme exceeds that from the climatological probability of track type. -from Authors