1970 Atlantic hurricane season

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1970 Atlantic hurricane season
Season summary map
First system formed May 17, 1970
Last system dissipated October 28, 1970
Strongest storm Celia – 945 mbar (hPa) (27.92 inHg), 125 mph (205 km/h) (1-minute sustained)
Total depressions 22
Total storms 10
Hurricanes 5
Major hurricanes (Cat. 3+) 2
Total fatalities 71
Total damage At least $930 million (1970 USD)
Atlantic hurricane seasons
1968, 1969, 1970, 1971, 1972

The 1970 Atlantic hurricane season officially began on June 1, 1970, and lasted until November 30, 1970. These dates conventionally delimit the period of each year when most tropical cyclones form in the Atlantic basin. The season was fairly average, with 10 total storms forming, of which five were hurricanes.

Notable storms of 1970 include Hurricane Celia, which killed 20 and caused $930 million in damages as it passed over Cuba and into Corpus Christi, Texas; Tropical Storm Dorothy, which killed 51, most in Martinique; and a tropical depression that was the wettest tropical cyclone in the history of Puerto Rico.


Storms[edit]

1970 Canada hurricane Tropical Storm Greta (1970) Tropical Depression Nineteen (1970) Tropical Storm Felice (1970) Hurricane Ella (1970) Tropical Storm Dorothy (1970) Hurricane Celia Tropical Storm Becky (1970) Hurricane Alma (1970) Saffir-Simpson Hurricane Scale

Hurricane Alma[edit]

Category 1 hurricane (SSHWS)
Duration May 17 – May 26
Peak intensity 80 mph (130 km/h) (1-min)  993 mbar (hPa)
Main article: Hurricane Alma (1970)

An area of disturbed weather persisted over the southwestern Caribbean Sea in the middle of May. It gradually organized, and a tropical depression formed on May 17. In response to low shear aloft and warm water temperatures, the depression rapidly strengthened on May 20, becoming a storm early in the day and a hurricane by night. However, Alma quickly weakened back to a tropical storm on May 21. Furthermore, it weakened to a tropical depression on the following day, mostly due to upper-level shear. The depression continued its general northward movement, with a brief jog to the west, and hit Cuba on May 24 as a 30 mph (48 km/h) tropical depression. As Alma crossed the eastern Gulf of Mexico, it retained a very well defined circulation with an eye appearing on radar, but shear limited convection and strength.

Alma made landfall near Cedar Key, Florida on May 25 as a tropical depression, and became extratropical two days later over North Carolina. Although Alma passed just offshore, impact in Central America, if any, is unknown. In the Cayman Islands, winds of 65 mph (105 km/h) was reported. Impact was severest in Cuba, where flash flooding caused seven fatalities, destroyed several homes, forced the evacuation of 3,000 people in Oriente Province, and resulted in a shutdown of 16 sugar mills. The storm brought light rainfall to Florida, peaking at 6.66 inches (169 mm) near Miami. Hazardous thunderstorms caused one death in Miami and damaged some roofs and building in Fort Myers. In other states, impact was mostly in the form of rain, though a tornado near Columbia, South Carolina destroyed a roof.

Tropical Storm Becky[edit]

Tropical storm (SSHWS)
Duration July 19 – July 23
Peak intensity 65 mph (100 km/h) (1-min)  1003 mbar (hPa)

A large disturbance began to detach from the Intertropical Convergence Zone near Panama on July 16. It is possible that the disturbance interacted with a low-level vortex over the northwest Caribbean Sea. By July 19, the disturbance developed into a tropical depression. After tracking through the Yucatan Channel, the depression became Tropical Storm Becky on July 20. Becky tracked northward to north-northeastward across the Gulf of Mexico and eventually strengthened to reach peak winds of 65 mph (105 km/h) late on July 20. Thereafter, upper level winds began weakening the storm. By July 22, Becky made landfall near Port St. Joe, Florida as either a minimal tropical storm or a tropical depression. The storm weakened further over land, eventually dissipating over western Kentucky on the July 23.

Throughout the state of Florida, Becky produced mostly light rainfall and gale force winds. However, in Tallahassee, the storm dropped more than 8 inches (200 mm) of rain, which caused flooding in and round the city. According to the Red Cross, 104 families in the Tallahassee region suffered flood-related losses. Additionally, two injuries were reported. Some houses near Tallahassee were flooded with 4 feet (1.2 m) of water, resulting in the evacuation of 15 households by rowboat. More than 100 cars in the area were also flooded. In nearby Wakulla County, knee-deep waters were reported at the county courthouse at Crawfordville. Additionally, a tornado spawned near Panacea, destroyed a house and damaged two others. Outside of Florida, effects were mainly limited to light to moderate rainfall, though a tornado in Georgia caused one fatality and destroyed two homes.

Hurricane Celia[edit]

Category 3 hurricane (SSHWS)
Duration July 31 – August 5
Peak intensity 125 mph (205 km/h) (1-min)  945 mbar (hPa)
Main article: Hurricane Celia

A tropical wave emerged into the Atlantic Ocean from the west coast of Africa in late July. It moved rapidly western and reached the western Caribbean Sea by July 30. On the following day, the system developed into a tropical depression near Grand Cayman. The depression tracked north-northwestward without significantly strengthening and struck crossed western Cuba on August 1. Heavy rains on the island caused severe flooding, leading to five fatalities. The depression entered the Gulf of Mexico and was upgraded to Tropical Storm Celia later on August 1. Due to warm sea surface temperatures, Celia rapidly intensified into a Category 3 hurricane on August 1. Storm surge and swells lashed the west coast of Florida, especially the Panhandle. Several life guard rescues occurred, while eight people drowned.

Early on August 2, Celia began to weaken and fell to Category 2 intensity. The storm weakened further to a Category 1 hurricane on August 3. However, while approaching the Texas coastline later that day, Celia began to rapidly intensify again. At 1800 UTC on August 3, Celia attained its peak intensity with maximum sustained winds of 125 mph (205 km/h) and a minimum barometric pressure of 945 mbar (27.9 inHg). In Louisiana, tides caused minor coastal flooding. Late on August 3, Celia made landfall near Corpus Christi, Texas. In Nueces County, wind gusts as high as 180 mph (290 km/h) were observed. Severe damage occurred in the county, with 85% of Celia's total property losses caused in Corpus Christi alone. Approximately 90% of downtown buildings were damaged or destroyed, while about one-third of homes in the city suffered severe impact or were demolished. Throughout the state, 8,950 homes were destroyed and damaged about 55,650 others. About 252 small businesses, 331 boats, and 310 farm buildings were either damaged or destroyed. Celia weakened as it continued further inland and dissipated over New Mexico on August 6. Overall, Celia caused 28 deaths and $930 million in damage. As a result, Celia was the costliest tropical cyclone in Texas history until Hurricane Alicia in 1983.

Tropical Storm Four[edit]

Tropical storm (SSHWS)
Duration August 15 – August 18
Peak intensity 70 mph (110 km/h) (1-min)  992 mbar (hPa)

A tropical depression formed in the western Atlantic Ocean near the Bahamas on August 15. It moved northwestward for a day, followed by a northeast motion for another day, but it remained weak. On August 18, in combination with baroclinic processes, the depression strengthened rapidly to a 70 mph (110 km/h) tropical storm prior to becoming extratropical on August 19 south of Newfoundland.[1] Light rainfall was reported in South Carolina, North Carolina, and Virginia; precipitation from the tropical storm peaked at 5.50 inches (140 mm) at the Marine Corps Air Station Cherry Point in North Carolina.[2]

Tropical Storm Dorothy[edit]

Tropical storm (SSHWS)
Duration August 17 – August 23
Peak intensity 70 mph (110 km/h) (1-min)  996 mbar (hPa)

A tropical wave moved off the western coast of Africa on August 13. Moving westward,[3] a tropical disturbance spawned by the wave led to the formation of a tropical depression beginning 500 miles (800 km) east of the Lesser Antilles on August 17. As it moved west-northwestward, it slowly intensified, and was upgraded to Tropical Storm Dorothy on August 19. By the following day, Dorothy attained its peak intensity with maximum sustained winds of 70 mph (110 km/h). Around that time, Dorothy crossed the island of Martinique. After passing through the Lesser Antilles, Dorothy moved under an upper-level cold-core trough, which caused the storm to weaken. On August 23, Dorothy dissipated south of the Tiburon Peninsula of Haiti.[4]

Throughout the Lesser Antilles, Dorothy produced high winds and heavy rainfall. On Martinique, large amounts of precipitation resulted in flooding and mudslides, which in turn, caused bridge collapses and damage to homes.[5] In addition, strong tropical storm force winds were also reported on the island. The storm destroyed 186 homes and left 700 people homeless.[6] Severe crop damage also occurred, especially to bananas and sugar cane. Flooding also occurred on Dominica and Guadeloupe, although effects were less severe.[5][7] The exact death toll of Dorothy is unknown, although some sources claim that as many as 51 fatalities occurred.[4] Dorothy also caused $34 million (1970 USD) in damage.[5]

Hurricane Ella[edit]

Category 3 hurricane (SSHWS)
Duration September 8 – September 13
Peak intensity 125 mph (205 km/h) (1-min)  967 mbar (hPa)
Main article: Hurricane Ella (1970)

Hurricane Ella developed from a surface trough near the Swan Islands in the western Caribbean on September 8. It moved northwestward without strengthening, but on September 10, as it moved into the Gulf of Mexico, it rapidly strengthened into a tropical storm, and a hurricane six hours later. Hurricane Ella gradually intensified prior to landfall, reaching 125 mph (201 km/h) winds on September 12 just before hitting the La Pesca/Soto la Marina area of the Mexican state of Tamaulipas. Ella rapidly dissipated over land.

Tropical Storm Felice[edit]

Tropical storm (SSHWS)
Duration September 12 – September 17
Peak intensity 70 mph (110 km/h) (1-min)  997 mbar (hPa)

An upper level trough led to the formation of a tropical depression on September 12 over the southern Bahamas. Land interaction limited strength initially, but as it moved into the Gulf of Mexico, it was able to strengthen to a 70 mph (110 km/h) tropical storm. Shortly after its peak Felice moved inland near High Island, Texas on September 16, and dissipated as a tropical cyclone the next day over northeastern Texas. The remnant low tracked slowly east-northeast across Arkansas before dissipating on September 19.

Tropical Depression Nineteen[edit]

Tropical depression (SSHWS)
Duration September 23 – October 11
Peak intensity 35 mph (55 km/h) (1-min)  1000 mbar (hPa)

The long-lived depression formed on September 24 just off the west coast of Africa, and for several days maintained a general westward track. It passed through the Lesser Antilles on October 1, and later stalled in the eastern Caribbean Sea. On October 8, the depression crossed over the eastern portion of the Dominican Republic, and subsequently it accelerated to the northeast. It was declassified as a tropical cyclone on October 12, although its remnants persisted for another week before dissipating in the westerlies near the Azores.[1][8]

The depression produced heavy rainfall in the Lesser Antilles, reaching 12 in (300 mm) on Barbados;[9] it left three deaths and moderate damage on the island.[10] Another death was reported in the United States Virgin Islands. Torrential rainfall on Puerto Rico inflicted heavy damage, totaling $65 million (1970 USD, $379 million).[1] The highest precipitation total was 41.68 in (1,059 mm) in Jayuya,[11] of which 17 in (430 mm) fell in a 24 hour period.[1] Most of the damage can be attributed to damaged sugar cane and coffee crops.[12] At least 18 people were killed on the island,[1] and the system was considered one of the worst disasters in Puerto Rican history.[13]

Tropical Storm Greta[edit]

Tropical storm (SSHWS)
Duration September 26 – October 5
Peak intensity 50 mph (85 km/h) (1-min)  1004 mbar (hPa)

A tropical wave exited western Africa and emerged into the Atlantic Ocean on September 15. Initially, it moved slowly westward, until September 22, when a high-pressure area caused it to accelerate west-northwestward towards the Leeward Islands.[3] By the next day, the wave interacted with a cold-core low, producing an area of convection. As the system moved over warmer waters, gale-force winds were measured. Because a surface low formed on September 26,[14] the system was then designated as Tropical Storm Greta. However, the storm did not strengthen, despite favorable conditions, and as a result, it was described as a "bomb that did not explode".[15][16]

While approaching the Florida Keys, Greta abruptly weakened to a tropical depression, coinciding with deterioration of the cloud pattern. In addition, Hurricane Hunters reported rising pressures and lower winds. On the evening of September 27, Greta made landfall in Key West, Florida with sustained winds of 26 mph (42 km/h).[15] Once in the Gulf of Mexico, Greta did not re-intensify, though it retained a closed circulation while moving around a high-pressure area. It moved across the northern Yucatán Peninsula, though it quickly re-emerged into the Gulf of Mexico. Eventually, Greta made landfall near Tampico, Mexico on October 5, and dissipated shortly thereafter.[16] Due to the weak nature of the storm, minimal impact was reported. In Florida, tides were generally minor, and were no more than 3 and 4 feet (0.91 and 1.22 m) in height, as reported in the Florida Keys.[17] Rainfall was mostly light, peaking at 8.94 inches (227 mm) in Fort Pierce.[14] Impact in Mexico is unknown.[15][16]

Hurricane Nine[edit]

Category 2 hurricane (SSHWS)
Duration October 12 – October 17
Peak intensity 105 mph (165 km/h) (1-min)  974 mbar (hPa)
Main article: 1970 Canada hurricane

On October 12, a subtropical depression developed while located northeast of the Bahamas. It steadily intensified and became a subtropical storm by the following day. After tracking east-northeastward, the storm made a sharp westward turned, followed by a curved to the north-northeast. After fully acquiring tropical characteristics, the subtropical storm transitioned into a tropical cyclone early on October 16. Twelve hours later, the storm strengthened into a hurricane,[8] shortly before passing near Bermuda.[18] It continued to intensify and briefly became a Category 2 hurricane on October 17. The hurricane then accelerated rapidly northeastward,[8] and made landfall on the Avalon Peninsula of Newfoundland as a Category 1 hurricane. Shortly thereafter, the hurricane transitioned into an extratropical cyclone on October 17.[8][19]

The hurricane produced high winds on Bermuda, causing suspension schools, transportation, and interrupted businesses, though minimal damage occurred.[20] In addition, light rainfall fell on the island.[21] Throughout Newfoundland, hurricane force winds were reported, which caused damage to structures, though mostly limited to broken windows. Rough seas along the Atlantic coast of the island damaged fishing dories and a fishing ramp. Heavy rainfall was also reported in the region, reaching nearly 5 inches (130 mm) in Quebec. Damage on the Burin Peninsula was in the thousands, although the specific figure is unknown. On the French Territory of Saint Pierre and Miquelon, several buildings lost their roof due to high winds.[19]

Hurricane Ten[edit]

Category 1 hurricane (SSHWS)
Duration October 20 – October 28
Peak intensity 75 mph (120 km/h) (1-min)  988 mbar (hPa)

A subtropical depression formed west of the Azores from an area of non-tropical origin on October 20. It strengthened to a tropical storm the next day. It slowly moved eastward, gaining strength but losing size. When it became a hurricane on October 27, its hurricane-force wind field was only 5 mi (8.0 km) in diameter and its tropical storm force wind field was only 60 mi (97 km) in diameter. This compact cyclone became extratropical on October 28 after passing safely by the Azores.

Other storms[edit]

In addition to the ten named storms of 1970 and one notable tropical depression, there were several minor systems that were also classified as depressions by the National Hurricane Center. The second tropical depression of the season (after Hurricane Alma) developed to the northeast of the Lesser Antilles on May 20. It moved north-northeastward without significant intensification and dissipated on the following day. Another tropical depression developed on June 19, while located about halfway between Cape Hatteras and Puerto Rico. It tracked northeastward in the general direction of Bermuda, but dissipated on June 20. A tropical wave emerged into the Atlantic from the west coast of Africa, while the previous tropical depression was dissipating. After tracking uneventfully across the Atlantic and much of the Caribbean Sea, the wave developed into a tropical depression north of Panama on June 30. Later that day, the depression made landfall near the Nicaragua/Costa Rica border. Although the depression dissipated within 24 hours later, the remnants redeveloped into Hurricane Francesca in the Pacific Ocean by July 1. A tropical depression, operationally numbered Seven, developed offshore of North Carolina on July 27. Initially, the depression tracked toward the Outer Banks, but veered east-southeastward and avoided landfall. While nearing Bermuda on July 30, the depression slowly curved north-northeastward. By early on August 2, the depression dissipated while located east of Cape Race, Newfoundland.[1]

Tropical Depression Nine developed on the same day in the vicinity of Cape Verde. It moved west-northwestward across the eastern-North Atlantic Ocean and eventually curved nearly due Eastward. The depression dissipated about halfway between Puerto Rico and the west coast of Africa on August 6. While Tropical Depression Nine was dissipating in the open Atlantic on August 5, Tropical Depression Ten developed near the Bahamas. By the following day, the depression dissipated while less than 100 miles (160 km) east of Central Florida.[1]

Storm names[edit]

The following names were used for named storms (tropical storms and hurricanes) that formed in the North Atlantic in 1970.[22] A storm was named Felice for the first time in 1970. Names that were not assigned are marked in gray.

  • Hallie (unused)
  • Isabel (unused)
  • Judith (unused)
  • Kendra (unused)
  • Lois (unused)
  • Marsha (unused)
  • Noreen (unused)
  • Orpha (unused)
  • Patty (unused)
  • Rena (unused)
  • Sherry (unused)
  • Thora (unused)
  • Vicky (unused)
  • Wilna (unused)

Retirement[edit]

The name Celia was later retired and replaced by Carmen in the 1974 Atlantic hurricane season.[23]

See also[edit]

References[edit]

  1. ^ a b c d e f g Frank, Neil L. (April 1971). "Atlantic Tropical Systems of 1970" (PDF). Monthly Weather Review (American Meteorological Society) 99 (4): 269–277. Bibcode:1971MWRv...99..269S. doi:10.1175/1520-0493(1971)099<0269:AHSO>2.3.CO;2. Retrieved 2011-01-06. 
  2. ^ Roth, David M. (2007-11-12). "Unnamed Tropical Storm - August 15-18, 1970". Hydrometeorological Prediction Center. Retrieved 2011-09-03. 
  3. ^ a b National Oceanic and Atmospheric Administration (January 1971). "1970 Atlantic hurricane season". Mariners Weather Log (Department of Commerce) 15 (1): 6. 
  4. ^ a b "Tropical Storm Dorothy Preliminary Report (Page 1)". National Hurricane Center. 1970. Retrieved 2011-09-03. 
  5. ^ a b c Staff Writer (1970-08-21). "Say Dorothy Killed 15 On Islands". United Press International. 
  6. ^ Perrusset, Marcell and Pierre Bouguen (1970). "La Tempête Tropicale Dorothy (Page 4)". Direction de la Meteorologie Nationale: Météorologique du Groupe Antilles-Guyane. Retrieved 2008-11-12. 
  7. ^ Staff Writer (1970-08-23). "Storm Dorothy Weakens, Still Poses Threat to Caribbean Sea Islands". United Press International. 
  8. ^ a b c d Roth, David M. (2011-02-14). "Extended Best Track Database for CLIQR program". Hydrometeorological Prediction Center. Retrieved 2012-03-24. 
  9. ^ Associated Press (1970-01-06). "Heavy Floods Hit Puerto Rico". Retrieved 2011-01-06. 
  10. ^ Office of U.S. Foreign Disaster Assistance (August 1993). "Significant Data on Major Disasters Worldwide 1990-present" (PDF). Retrieved 2011-01-06. 
  11. ^ Roth, David M. (2008-09-24). "Tropical Depression #19 - October 2-10, 1970". Hydrometeorological Prediction Center. Retrieved 2011-01-06. 
  12. ^ Associated Press (1970-10-12). "Puerto Rico Starts Flood Cleanup Job". Spokesman Review. Retrieved 2011-01-06. 
  13. ^ Associated Press (1970-10-08). "Floods Kill 10 In Barbados, Puerto Rico". Morning Record. Retrieved 2011-01-06. 
  14. ^ a b Roth, David. "Tropical Storm Greta - September 26-October 1, 1970". Hydrometeorological Prediction Center. Retrieved 2011-09-26. 
  15. ^ a b c "Preliminary: Tropical Storm Greta". National Hurricane Center. Retrieved 2011-09-26. 
  16. ^ a b c Pelissier, Joseph and Robert Simpson. "Atlantic hurricane season of 1970". National Hurricane Center. Retrieved 2011-09-26. 
  17. ^ "National Hurricane Center Marine/Aviation Special Advisory Number 4 Tropical Storm Greta". National Hurricane Center. Retrieved 2011-09-26. 
  18. ^ Spiegler, David (December 1971). "The unnamed Atlantic Tropical Storms Of 1970". National Oceanic and Atmospheric Administration. Retrieved March 24, 2012. 
  19. ^ a b "1970-NN-2". Environment Canada. May 5, 2011. Retrieved September 3, 2011. 
  20. ^ United Press International (October 16, 1970). "Winds Lash Bermudians". The Beaver County Times. Retrieved March 24, 2012. 
  21. ^ Roth, David M; Hydrometeorological Prediction Center (November 16, 2012). "Tropical Cyclone Rainfall Point Maxima". Tropical Cyclone Point Maxima. United States National Oceanic and Atmospheric Administration's National Weather Service. Retrieved December 7, 2012. 
  22. ^ http://news.google.com/newspapers?id=vKZGAAAAIBAJ&sjid=ySwNAAAAIBAJ&pg=2104,6307383&dq=hurricane+retire+name&hl=en
  23. ^ "Retired Hurricane Names Since 1954". Archived from the original on 2009-08-11. Retrieved 2009-08-07. 

External links[edit]