Figure 1. West African and Atlantic Ocean regions (6◦ × 6◦ ) chosen for climatological analysis. Plots inside each regional domain indicate the relative
proportion of precipitation features (using contiguous precipitation radar reflectivity) occurring in the trough (‘T’), southerly (‘S’), ridge (‘R’), and
northerly (‘N’) African easterly wave phases; and when no wave was identified (‘O’). Fractions are calculated by using the number of features in each
phase divided by the total number of features in that region.