Contributed by Bill McCaul

Almost all tropical cyclones making landfall in the United States spawn at least one tornado, provided enough of the TC's circulation moves over land. This implies that Gulf coast landfalling TC's are more likely to produce tornadoes than Atlantic coast TC's that "sideswipe" the coastline. The rate at which TC's produce tornadoes (waterspouts) over the ocean is unknown, although Doppler radars have identified many cases where storm cell rotation suggestive of the presence of tornadoes was observed over water, and there have been a number of cases where TC-spawned waterspouts have been witnessed from shore, with some of these coming ashore as tornadoes (McCaul, 1991); see also the website:

http://www.tornadoproject.com/alltorns/tcyclone2.htm

Last updated October 4, 2006