Return periods for Hurricane Katrina

Hurricane Katrina is the most destructive natural disaster in U.S. history. The relative infrequency of severe coastal hurricanes implies that empirical probability estimates of the next big one will be unreliable. Here we use an extreme-value model and show that a hurricane of Katrina's intensity or stronger can be expected to occur, on average, once every 21 years somewhere along the Gulf coast and once every 14 years somewhere along the entire coast from Texas to Maine. The model predicts a 100-year return level of 83 m/s (186 mph) during globally warm years and 75 m/s (168 mph) during globally cool years. The magnitude of this difference is consistent with models predicting an increase in hurricane intensity with increasing greenhouse warming.

[with T.H. Jagger & A.A. Tsonis]

Definition: Hurricane Climate

Hurricane climate is the study of hurricanes that includes the role climate factors play in modulating seasonal, annual, and decadal hurricane activity. Hurricane climatology is the statistics (e.g., mean number of hurricanes, maximum estimated intensity, etc.) of past hurricane activity over some reference time period. The role climate factors play in modulating hurricane activity are examined using empirical, statistical, or dynamical models. For hurricanes occurring over the North Atlantic, climate factors include El Niño, the North Atlantic Oscillation (NAO), the Atlantic sea-surface temperature (SST), and the stratospheric Quasi-Biennial Oscillation (QBO). Hurricane climate also includes the role global warming might have on hurricane activity.