Short-Fuse Hurricanes: Time to Landfall and the Influence of ENSO

The time between tropical storm formation and landfall is an underappreciated aspect of the coastal hurricane hazard. Many coastal areas in the United States require several days for hurricane evacuation, and thus require several days' advance warning of the risk of hurricane landfall. Yet, some hurricanes may form, intensify, and make landfall entirely within that several days' window. This study examines the length of time between tropical storm formation and landfall along the Gulf and Atlantic coasts of the United States using a one-million-storm synthetic data set created by a statistical hurricane simulator. For all United States landfalling storms, the average time between formation and landfall was 5.4 days. This duration was a weak function of ENSO state, with landfall slightly sooner during El Niņo years. Stronger storms, on average, make landfall longer after formation. Time to landfall is smallest in Texas and increases for states farther east and northeast. The annual risk of a major hurricane making landfall within four days of formation is about 2.5% in Texas and Florida, 1.5% in Louisiana, and much less in other states, and such odds are enhanced during La Niņa conditions.