Hurricane Dennis (1981)

Hurricane Dennis
Category 1 hurricane (SSHWS/NWS)

Hurricane Dennis off the North Carolina coastline
Formed August 7, 1981
Dissipated August 22, 1981
Highest winds 1-minute sustained: 80 mph (130 km/h)
Lowest pressure 995 mbar (hPa); 29.38 inHg
Fatalities No fatalities reported
Damage $17 million (1981 USD)
Areas affected Lesser Antilles, Puerto Rico, Hispaniola, Jamaica, Isle of Youth, Cuba, The Bahamas, Florida, Georgia, Carolinas, Virginia
Part of the 1981 Atlantic hurricane season

Hurricane Dennis was the most damaging storm of the 1981 Atlantic hurricane season which took twelve and a half days to reach hurricane status. The tropical wave that later would become Dennis moved off the African coastline on August 5. By August 7 a tropical depression developed, which quickly intensified into Tropical Storm Dennis, the 4th named storm of the 1981 season. As Dennis approached the Caribbean Sea, strong upper level winds degenerated the storm back into a tropical wave by August 11. On August 15 Dennis regained tropical storm status as it crossed Cuba and moved into the Straits of Florida. On the 18th and 19 August, Dennis traversed the Florida peninsula as a weak tropical storm and later moved offshore. Dennis then skirted the Carolinas and briefly reached hurricane strength before being declared extratropical on August 22.

Dennis left $15 million (1981 USD, $34.4 million in 2007 USD) in damage to the agriculture to Florida, with minor rainfall and effects farther north up the coast.

Meteorological history

Map plotting the track and intensity of the storm according to the Saffir–Simpson hurricane wind scale

Hurricane Dennis formed from a tropical system that was well organized after entering the Atlantic Ocean from Africa on August 5.[1] The system quickly intensified and became a tropical depression on August 7 as it headed westward. The depression strengthened into Tropical Storm Dennis about 12 hours later.[2] Dennis continued westward as a tropical storm for three days before entering an area of wind shear, which weakened the system.[1] Dennis was downgraded to a tropical depression on August 11, and after entering the Caribbean Sea, weakening into a tropical wave. The wave continued westward, passing to the south of Puerto Rico and the U.S. Virgin Islands before turning to the northeast towards Cuba. The wave made landfall in Jamaica before stalling near Cuba.

While it was stationary, the tropical wave began to come back together, strengthening into Tropical Depression Dennis on August 15.[1] The system quickly re-attained tropical storm status and crossed over Cuba. Slower, yet constant strengthening occurred, and Dennis began to form an eye on satellite photos. Dennis made landfall near Key West on August 18 and crossed across the state. During the day and the day after, Dennis crossed Florida and headed up the east coast. On August 21, Dennis turned away from the coast and strengthened into a hurricane, peaking at 80 mph (130 kilometres) that day. Dennis moved over colder waters and became extratropical on August 22.[1]

Preparations and impact

Total rainfall in the United States from Dennis

As Dennis approached the Florida Keys, several gale warnings were issued, with the first from Long Key to Dry Tortugas at 04:00 UTC on August 16. These gale warnings were posted progressively farther north along the East Coast of the United States, reaching as far north as Windmill Point in Virginia. Additionally, a hurricane watch was issued in South Florida from Fort Myers to Palm Beach, including the Florida Keys.[3] Hundreds of people were evacuated from the campgrounds of Bahia Honda and John Pennekamp state parks. Shelters were also prepared to open in the Florida Keys if necessary.[4] A number of people evacuated Myrtle Beach, South Carolina, as Tropical Storm Dennis approached.[5]

Rainfall totals in South Florida were generally between 5 and 10 in (130 and 250 mm), providing relief for a drought that began in spring. However, little precipitation fell in Lake Okeechobee.[6]

Rainfall in the state of Florida was beneficial, helping to cease a drought that was persistent through spring and early summer. However, little rain fell in the Lake Okeechobee area, which needed considerable relief. Rains peaked around 20—25 inches (510–635 mm) in the Miami-Dade area, where at least 20 families had to be rescued by airboats and 4-wheel drive vehicles.[6][7]

There were major losses to commercial and residential buildings due to roof failures caused by Dennis.[6] However, heavier damage was sustained to the agriculture of Florida. due to prolonged water from Dennis. Damage was estimated at $15 million (1981 USD, $34 million in 2007 USD) in the Miami-Dade region alone. The standing water also caused health issues for local residents. There were two tornadoes reported in associated with Dennis, one on Plantation Key and one in northern Dade County. Minor damage was reported from both of the two tornadoes.[6]

In response to the flooding, Governor of Florida Bob Graham signed an executive order authorizing 10 high-axle combat vehicles and 20 National Guardsmen to assist in the evacuation of residents south of Miami. Three evacuation shelters were opened for those displaced from their homes.[8]

Regions north of Florida sustained lighter effects. Rainfall peaked at around 10 inches (250 mm) in parts of North Carolina.[7] There were similar, but less extensive losses to agriculture to areas such as Georgia and South Carolina.[6] Flooding stretched from Georgia to extreme parts of Virginia, where localized flooding and beach erosion occurred.[6] $2 million (1981 USD, $4.54 million in 2007 USD) worth of damage was reported in the beach city of Myrtle Beach.[5]

See also

References

  1. ↑ 1.0 1.1 1.2 1.3 National Hurricane Center (1981). "Hurricane Dennis Preliminary Report (Page 1)". Retrieved 2008-01-05.
  2. ↑ National Hurricane Center (1981). "Hurricane Dennis Preliminary Report (Page 10)". Retrieved 2008-01-06.
  3. ↑ Watches and Warnings. National Hurricane Center (Report) (Miami, Florida: National Oceanic and Atmospheric Administration). 1981: 3. Retrieved 2014-09-04.
  4. ↑ Randall Hackley (1981-08-17). "Hurricane watch continues in South Florida" (PDF). The Daily Collegian (Islamorada, Florida). Associated Press. p. 1. Retrieved 2014-09-04.
  5. ↑ 5.0 5.1 Associated Press (1981-08-21). "Hurricane Dennis heads out to sea". Marysville Journal-Tribune. Retrieved 2008-01-06.
  6. ↑ 6.0 6.1 6.2 6.3 6.4 6.5 Preliminary Report: Hurricane Dennis 7 – 21 August 1981. National Hurricane Center (Report) (Miami, Florida: National Oceanic and Atmospheric Administration). 1981: 2. Retrieved 2014-09-04.
  7. ↑ 7.0 7.1 David Roth (2008). "Rainfall data for Hurricane Dennis". Retrieved 2008-01-06.
  8. ↑ "Tropical Storm Crosses Florida, Traveling North". The New York Time (Miami, Florida). United Press International. 1981-08-19. Retrieved 2014-09-04.

External links

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