Some Aspects of Eastern North Pacific Tropical Cyclones

The Eastern North Pacific (ENP) basin is one of the most prolific regions for TCs in the world. Since World War II surveillance efforts over this region have gradually increased, providing more accurate and reliable records of tropical cyclones (TCs). Nevertheless, there have been few climatological studies concerning TC activity over this global region. However, most of which has been concluded about these TCs can be considered preliminary since reliable data sources were somewhat limited at the time these studies were completed. The fact that few landmasses are affected and that data are sparse over this region has led to a general neglect of ENP TCs. Here basic characteristics of ENP TCs are uncovered in an effort to better understand their climatology.

ENP TCs have certain defining characteristics. The majority of all ENP TCs form between late May and the middle part of October, and their genesis is concentrated in a narrow region between 10N and 20N and 95W and 115W. An average of 16 named storms, 9 hurricanes, and 5 major hurricanes form each season. Most ENP TCs exhibit west to northwest tracks as a consequence of the mean summertime flow features. However, recurvature is possible during the early and late season. Additionally, ENP TCs can affect the Mexican coast, with an average of 2.4 (1.4) named storms (hurricanes) making landfall each season. The greatest threat of TC strikes is during September and October; major hurricane landfalls are quite rare. Finally, other important aspects of ENP TCs are discussed, including intraseasonal variability, correlations with activity in other basins, and seasonal length.