Observed Influence of the Atlantic Warm Pool on Atlantic Tropical Cyclones

Regional climate features have a profound influence over the interannual and seasonal variability of North Atlantic tropical cyclones. One such regional climate feature is the Atlantic Warm Pool (AWP), a varying body of warm water across the Gulf of Mexico, Caribbean Sea, and western Atlantic Ocean. Analyses based upon observational datasets indicate that variations of the areal extent of the AWP noticeably influenced regional tropical cyclogenesis in the North Atlantic basin during the satellite era (post-1966). As a whole, Atlantic tropical cyclone frequencies are enhanced (diminished) in years in which the AWP is anomalously large (small). However, further analysis of the historical record reveals that the AWP does not have a uniform effect upon tropical cyclone climatology for the entire basin. The size of the AWP greatly influences counts of eastern Atlantic tropical storms, increasing (decreasing) eastern Atlantic storm counts in anomalously large (small) AWP years, as observed in earlier studies. In the western Atlantic basin, however, the AWP influences the preferred location of genesis rather than the number of storms. This influence on genesis location is best observed in the Caribbean region as a result of potential connections between the Caribbean low-level jet, the North Atlantic subtropical high and the AWP.