FLHurricane.com: Active Period / Quiet Period

The Atlantic Basin has been in a cycle of increased tropical cyclone activity since 1995 and that cycle is expected to continue in 2013 with a higher than normal number of tropical storms expected in the basin. In the past three years there were 29 hurricanes but only 3 - Irene in 2011 and Isaac and Sandy in 2012 - that made landfall as a hurricane in the continental United Status (although Sandy was not considered as a landfalling hurricane by , many meteorologists disagree).

The start of the new season will soon be upon us and as of June 1st the entire state of Florida will have gone 2,777 days (7.6 years) without a landfalling hurricane - which is the longest hurricane landfalling drought in the Sunshine State since a 9 year stretch in the 1850s-1860s - and all of this during an active period in the Atlantic basin. But with regard to the frequency of landfalling U.S. hurricanes, does it make any difference if the basin is in an 'active' period or a 'quiet' period? The surprising answer is 'not much at all'. For the state of Florida there is a slightly greater risk during an active phase, but for the entire coastline from Brownsville, Texas, to Eastport, Maine, the risk is actually slightly higher when the Atlantic basin is in a period of lower tropical cyclone activity.

From 1995 - 2012 (active period): 144 hurricanes, 31 U.S. landfalls (21.5%), 9 Florida landfalls (6.3%)

From 1977 - 1994 (quiet period): 91 hurricanes, 22 U.S. landfalls (24.2%), 4 Florida landfalls (4.4%)

During the active period (1995 - 2012) 13 of the 18 seasons had a U.S. hurricane landfall and 5 of those seasons had a landfall in Florida - i.e., 13 seasons had no landfalling hurricane in Florida. During the inactive period of 18 seasons (1977 - 1994) 12 of the seasons had a U.S. hurricane landfall and 4 of those seasons had a landfall in Florida - i.e., 14 seasons had no landfalling hurricane in Florida. Finally, the inactive period also had a long stretch without any Florida hurricane landfalls - from October 12, 1987 to August 23, 1992 - 1,777 days (4.86 years). Although the sample set is small, there seems to be no significant correlation between the number of U.S. landfalling hurricanes and the Atlantic basin cycles of tropical cyclone activity, however, the length of time that Florida has gone without a hurricane landfall increases the probability that the state will experience one this season. With the expectation for another busy tropical season, now is the time to develop (or update) your hurricane preparedness plan.
ED