Performance of a Genesis Index in Predicting Seasonal and Geographic Distributions of Tropical Cyclogenesis
Details of the index can be found in the Preprints of the 26th Conference on Hurricanes and Tropical Meteorology, available here.
The index is defined:
The figure below compares the seasonal cycle of this index with the observed seasonal cycle of genesis events in the Northern Hemisphere:
The graph below is the same, but for the Southern Hemisphere:
The next 12 graphs (one for each month) show how well the index predicts the geographical distribution of genesis events. In each graph, the coloring shows the index value, while the asterisks show points at which tropical cyclones were observed to form.