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The 1972 Hurricane Agnes tornado outbreak, the third-deadliest tropical cyclone-related outbreak in the United States since 1900, was the deadliest tornado outbreak related to a tropical cyclone in Florida. The outbreak, produced by Hurricane Agnes, lasted about 15 hours on June 18–19, 1972. In all, the outbreak resulted in 30 tornadoes in Florida and Georgia, including 6 F0 events, 12 F1 events, 10 F2 events, and two F3 events on the Fujita scale. Originally, only fifteen tornadoes were confirmed. Two of the tornadoes killed seven people and were not officially classified as tornadoes in the National Weather Service records. In Florida alone, the outbreak inflicted at least 140 injuries and destroyed fifteen homes, while 119 homes received damage. In that state, 217 trailers were destroyed and 196 trailers incurred damage. Additionally, six Florida businesses were destroyed, while six others were damaged.
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Meteorological synopsis
The interaction of baroclinic features with Agnes resulted in a tropical cyclone with "hybrid" characteristics, which increased the threat of strong tornadoes with longer path lengths. The outbreak became the most significant tornado outbreak associated with a tropical cyclone prior to landfall. The presence of strong wind shear surrounding the tropical cyclone facilitated the development of strong tornadoes, including the greatest number of tornadoes of at least F2 intensity within one 24-hour period in Florida. Studies have suggested strong wind shear in the lower levels of the atmosphere is a common feature during tornado outbreaks involving the outer rain bands of tropical cyclones near Florida. Additionally, in Florida cases, the favored region for tornado outbreaks is the northeastern quadrant of north moving tropical cyclones. Agnes represented one of these cases.
LaBelle/Okeechobee, Florida
On June 18, a tornado touched down around 4:13 p.m. (EDT) near Fort Denaud, which is located near LaBelle in Hendry County. The tornado, killing one person, destroyed a truck and a trailer. The funnel also prostrated citrus trees and caused six injuries near LaBelle. Ten mobile homes were destroyed in two mobile home parks. In all, the tornado affected three mobile home parks and inflicted $200,000 (1972 USD) in property damage. Another tornado, occurring around 10:55 p.m. (EDT), destroyed 50 mobile homes and one fish camp near Okeechobee. This event killed six people and caused damage along a path that reached a width of 100 yards (0.05 mi). These tornadoes were operationally classified as "windstorms" in the official National Weather Service database, which indicated severe thunderstorm winds were responsible for the seven deaths. However, newspaper reports did cite the Okeechobee event as a tornado. Subsequently, an independent case study of the Hurricane Agnes outbreak in 1998 unveiled evidence that the events were two strong (F2–F3) tornadoes. However, the official database still lists the original number of tornadoes.
Unconfirmed tornadoes
There were two unconfirmed tornadoes in Collier County. A brief tornado reportedly damaged a roof and two planes in the town of Immokalee. Power lines were downed in the area. Another possible tornado affected Everglades City, where trees were prostrated and portions of a home were transported for 0.25 mile (0.4 km). Lee County was affected by three F2 tornadoes, while an F1 tornado touched down in Seminole County. In all, the tornadoes in Lee, Seminole, and Brevard counties produced damages in excess of $100,000 (1972 USD).
Oddities/records
Agnes produced a total of 8–11 strong (F2–F3) tornadoes in Florida. The accuracy of the ratings for many strong tornadoes in the 1950s, 1960s, and 1970s has been questioned by some authorities. Thomas P. Grazulis states that his criteria yielded fewer strong tornadoes than the official records. The author cites only four strong tornadoes for the Hurricane Agnes tornado outbreak. Only one F3 tornado is listed, while three F2 tornadoes are included in the analysis. The official database lists six F2 events and two F3 events.