Exploring QBO-atlantic hurricane relationships prior to 1950

Extensive prior work by W. M. Gray and colleagues has amply demonstrated the influence of the stratospheric QBO on the incidence of Atlantic tropical cyclones during the years since the discovery of the QBO, about 1950. A provisional index of the QBO phase during the 80 years prior to 1950 has been constructed from various proxy information and scattered direct observations. The presentation will review (1) both the pre-1950 QBO index and results of a QBO based stratification of Atlantic hurricane activity extending back to 1870 wherein the established basic associations (ie., diminished activity during QBO east phase years) are generally observed and (2), evidence of a significant additional dependence of the QBO effect on SST anomaly trends in the off-equator, tropical northeast Pacific areas west of Mexico and Central America.