Hurricane Agnes tornado outbreak

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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.[1]

Meteorological synopsis[edit]

Satellite image of Hurricane Agnes
Reanalysis of the 1972 Hurricane Agnes tornado outbreak

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.[2][3] The outbreak became the most significant tornado outbreak associated with a tropical cyclone prior to landfall.[1] 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.[1][2] 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.[4] 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.[4][5]

Officially recorded tornadoes[edit]

Confirmed
Total
Confirmed
F0
Confirmed
F1
Confirmed
F2
Confirmed
F3
Confirmed
F4
Confirmed
F5
17 1 7 7 2 0 0

June 18[edit]

List of confirmed tornadoes
F#
Location
County
Time (UTC)
Path length
Damage
Florida
F2 Big Coppitt Key Monroe 0615 1 mile
(1.6 km)
In all, five homes and 47 trailers incurred damage. One frame residence lost its roof. 40 people were injured.[6] Damages reached $342,000 (1972 USD).[7]
F2 Key West Monroe 0700 1 mile
(1.6 km)
Buildings were destroyed and lost roofs on the northern side of Key West. 50 people were injured.[6] Losses reached $400,000 (1972 USD).[7]
F1 Key Colony Beach to Long Key Monroe 1000 2 miles
(3.2 km)
The funnel passed through Key Colony Beach, Grassy Key, Conch Key, and Long Key. The majority of the damage occurred on Conch Key, where the tornado damaged six trailers. Damages were below $10,000 (1972 USD).[7]
F1 Basinger area Okeechobee 1755 1 mile
(1.6 km)
The tornado touched the ground on U.S. Route 98. Two trailers were destroyed. One person received injuries, and four trailers were damaged. Damages reached $20,000 (1972 USD).[7]
F2 Sanibel Island Lee 1838 0.3 mile
(0.5 km)
Five stores and the roof of a church were destroyed. Losses reached $15,000 (1972 USD).[7]
F2 Pine Island Lee 1900 2 miles
(3.2 km)
The tornado passed through three trailer parks and destroyed four trailers. Several stores received damage. Losses were near $50,000 (1972 USD).[7]
F1 Haines City area Polk 1910 0.3 mile
(0.5 km)
Six mobile homes were severely damaged at the Haines City Mobile Home Park. Three minor injuries occurred. Damages reached $43,000 (1972 USD).[7]
F2 Lehigh Acres Lee 2000 0.5 mile
(0.8 km)
One TV transmitting tower was destroyed. Damages were estimated at $60,000 (1972 USD). The path of the tornado moved north.[7]
F1 S of Zephyrhills Pasco 2140 0.2 mile
(0.3 km)
The tornado, striking Crystal Springs, damaged several mobile homes. Four people were injured. One of the injuries was classified as serious. Damages reached $20,000 (1972 USD).[7]
F1 North Palm Beach area Palm Beach 2240 0.3 mile
(0.5 km)
Tennis courts, a sailboat, and one home received damage. Losses reached $10,000 (1972 USD).[7] The sailboat was lifted from a lake and deposited on a roof.[8]
F0 W of Okeechobee Highlands 2245 1 mile
(1.6 km)
A brief tornado produced minimal damage near the intersection of the Kissimmee River and State Road 70.[7]
F2 Malabar Brevard 2346 2 miles
(3.2 km)
The Century Oaks Trailer Park was affected. In all, six trailers were destroyed, while nine trailers incurred damage. Homes were also damaged in Port Malabar. 11 people were injured, and damage estimates reached $100,000 (1972 USD) at the trailer park.[7][8]
Sources: NCDC Storm Events Database, SPC Storm Data, NCDC Storm Data publication, Significant Tornadoes 1680-1991: A Chronology and Analysis of Events by Thomas P. Grazulis

June 19[edit]

List of confirmed tornadoes
F#
Location
County
Time (UTC)
Path length
Damage
Florida
F3 Merritt Island Brevard 0635 4 miles
(6.4 km)
One apartment building was destroyed as the tornado struck a subdivision.[6] Two hangars were destroyed at the Merritt Island Airport, where 44 planes were also completely destroyed.[6][7] One plane was carried more than 0.25 mile (0.40 km) from the airport and crashed into one home.[8] Damages reached $3 million (1972 USD).[7] One source, citing F2 damage, suggests that the tornado never attained F3 intensity.[6]
F3 Cape Canaveral Brevard 0700 3 miles
(4.8 km)
The second F3 tornado struck the town of Cape Canaveral.[8] Two homes and 30 trailers were destroyed. The Port Canaveral Coast Guard station incurred $50,000 (1972 USD) in damages. 20 other homes were damaged, 100 residents were left homeless, and 23 people were injured.[6] Losses exceeded $500,000 (1972 USD).[7]
F1 Geneva area Seminole 0849 0.1 mile
(0.2 km)
Five homes were destroyed within a narrow swath of a trailer park. Losses reached $40,000 (1972 USD).[7]
Georgia
F1 SE of Homestead Pierce 1825 1 mile
(1.6 km)
The first tornado in Georgia related to Agnes touched down around 12:25 pm CST near Homestead. The F1 tornado produced minor damage along its path; however, one person sustained injuries. Losses were estimated up to $25,000 (1972 USD).[7]
F2 NE of Bethel Coffee 2000 2 miles
(3.2 km)
The second and strongest tornado in Georgia related to Agnes touched down around 2:00 pm CST near Bethel. The F2 tornado produced moderate damage along its path, with losses estimated up to $250,000 (1972 USD).[7]
Sources: NCDC Storm Events Database, SPC Storm Data, NCDC Storm Data publication, Significant Tornadoes 1680-1991: A Chronology and Analysis of Events by Thomas P. Grazulis

Notable tornadoes[edit]

LaBelle/Okeechobee, Florida[edit]

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.[1][7] Another tornado, occurring around 10:55 p.m. (EDT),[7] destroyed 50 mobile homes[1] and one fish camp near Okeechobee.[6] This event killed six people[6] and caused damage along a path that reached a width of 100 yards (0.05 mi).[1] These tornadoes were operationally classified as "windstorms"[9] in the official National Weather Service database, which indicated severe thunderstorm winds were responsible for the seven deaths.[1][4] However, newspaper reports did cite the Okeechobee event as a tornado.[6] Subsequently, an independent case study of the Hurricane Agnes outbreak in 1998 unveiled evidence that the events were two strong (F2–F3) tornadoes.[1][3] However, the official database still lists the original number of tornadoes.[10]

Unconfirmed tornadoes[edit]

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).[8] Lee County was affected by three F2 tornadoes, while an F1 tornado touched down in Seminole County.[10] In all, the tornadoes in Lee, Seminole, and Brevard counties produced damages in excess of $100,000 (1972 USD).[8]

Oddities/records[edit]

Agnes produced a total of 8–11 strong (F2–F3) tornadoes in Florida.[1][10] 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.[6] The official database lists six F2 events and two F3 events.[10]

See also[edit]

References[edit]

  1. ^ a b c d e f g h i Hagemeyer, Bartlett C. et al. "Thirty Years After Hurricane Agnes - The Forgotten Florida Tornado Disaster". American Meteorological Society. Archived from the original on October 16, 2008. Retrieved 2008-11-15. 
  2. ^ a b "Hurricanes and Tornadoes". Central Pacific Hurricane Center. Archived from the original on 3 November 2008. Retrieved 2008-11-15. 
  3. ^ a b Hagemeyer, Bartlett C. "1.2: Significant Tornado Outbreaks Associated With Tropical Cyclones in Florida". National Weather Service Melbourne, Florida office. Archived from the original on 2009-05-05. Retrieved 2009-03-06. 
  4. ^ a b c Hagemeyer, Bartlett C (1997). "Peninsular Florida Tornado Outbreaks". American Meteorological Society. Archived from the original on 12 June 2011. Retrieved 2008-11-15. 
  5. ^ Hagemeyer, Bartlett C. et al. "Florida Tornado Outbreaks Associated With Tropical Cyclones". National Weather Service Melbourne, Florida office. Archived from the original on 2008-06-17. Retrieved 2008-11-15. 
  6. ^ a b c d e f g h i j Grazulis, Thomas P. (1993). Significant Tornadoes 1680-1991: A Chronology and Analysis of Events. Environmental Films.
  7. ^ a b c d e f g h i j k l m n o p q r s t U.S. Department of Commerce (1972). Storm Data: June 1972 (Vol. 14, No. 6). NOAA.
  8. ^ a b c d e f "Tornadoes". Naples Daily News. Retrieved 2008-11-15. [dead link]
  9. ^ U.S. Department of Commerce (1972). Storm Data: June 1972 (Vol. 14, No. 6) NOAA.
  10. ^ a b c d National Climatic Data Center. "Storm Events Database". NOAA. Archived from the original on 2008-08-12. Retrieved 2008-11-15.