Hurricane Greta–Olivia Explained

Hurricane Greta—Olivia
Formed:September 13, 1978
Dissipated:September 23, 1978
Winds:115
Pressure:947
Year:1978
Fatalities:5 direct
Damage:26000000
Areas:Windward Islands, Central America (particularly Honduras), Belize, Mexico
Season:1978 Atlantic and
Pacific hurricane seasons

Hurricane Greta, later Hurricane Olivia, was one of fourteen named Atlantic hurricanes to cross over Central America into the eastern Pacific while remaining a tropical cyclone. The seventh named storm of the 1978 Atlantic hurricane season, Greta formed from a tropical wave just northwest of Trinidad on September 13, and despite being in a climatologically unfavorable area, gradually intensified while moving west-northwestward. On September 16, it became a hurricane south of Jamaica. Two days later, the well-defined eye approached northeastern Honduras but veered to the northwest. After reaching peak winds of 130mph that day, Greta weakened while paralleling the northern Honduras coast just offshore. On September 19, it made landfall on Belize near Dangriga and quickly weakened into a tropical depression while crossing Guatemala and southeastern Mexico. After entering the eastern Pacific, the system re-intensified into a hurricane and was renamed Olivia, the eighteenth named storm of the 1978 Pacific hurricane season which weakened before landfall and dissipated over Chiapas on September 23.

Taking a similar path to Hurricane Fifi four years prior, Greta threatened to reproduce the devastating effects of the catastrophic storm; however, damage and loss of life was significantly less than feared. In Honduras, about 1,200 homes were damaged, about half of which in towns along the coastline. The storm damaged about 75% of the houses on Roatán along the offshore Bay Islands, and there was one death in the country. In the Belize Barrier Reef, Greta downed trees and produced high waves, while on the mainland, there was minimal flooding despite a high storm surge. In Dangriga where it made landfall, the hurricane damaged or destroyed 125 houses and the primary hospital. In Belize City, a tornado flipped over a truck and damaged four houses. Damage in Belize was estimated at $25 million (1978 USD), and there were four deaths.

Meteorological history

A tropical wave exited the west coast of Africa near Dakar, Senegal on September 7. Moving westward across the Atlantic Ocean, the wave spawned an area of convection three days later, which gradually organized. On September 13, the wave moved through the Windward Islands, producing wind gusts of 50mph on Barbados. Later that day, it is estimated the system developed into a tropical depression about 75miles west-northwest of Trinidad, based on ship and land reports. Though located in a climatologically unfavorable area, the depression intensified and continued to develop. A hurricane hunter on September 14 indicated that the depression intensified into Tropical Storm Greta to the north of the Netherlands Antilles.[1]

After becoming a tropical storm, Greta intensified slowly due to a strong trough to the northwest,[1] and with the South American coastline located to the south, the southerly inflow was disrupted.[2] With a ridge to the north along the 30th parallel, the storm moved quickly west-northwestward across the Caribbean.[3] On September 16, Greta intensified into a hurricane about 275miles south of Jamaica.[1] Shortly thereafter, the trough to the northwest weakened, which had been preventing the storm's intensification.[1] An increasingly well-defined eye developed while approaching the coast of Honduras as the barometric pressure quickly dropped. Early on September 18, the eyewall passed just offshore Cabo Gracias a Dios, the sparsely populated border between Honduras and Nicaragua[4] The NHC described the eye as having "literally ricocheted off of the protruding northeast coast of Honduras", thus sparing much of the country from the strongest winds. At 0710 UTC on September 18, the Hurricane hunters observed a minimum pressure of 947mbar just off the northern Honduras coast, which was the basis for the estimated peak intensity of 130mph.[5] This made it a Category 4 hurricane on the Saffir–Simpson scale.

Despite the proximity to land, Greta initially maintained a well-defined structure. The hurricane continued generally west-northwestward due to the ridge to the north, and initially was expected to enter the Bay of Campeche.[6] After passing through the Bay Islands off northern Honduras,[4] Greta weakened slightly while approaching Belize, and made landfall near Dangriga at 00:00 UTC on September 19,[5] with winds of about 110mph.[7] The calm of the eye was reported for three to five minutes there.[8] Rapidly weakening over land, the hurricane deteriorated to tropical depression status over Guatemala within 12 hours of landfall. A large high pressure area from the Carolinas to the central Gulf of Mexico turned Greta southwestward toward the eastern Pacific Ocean.[9] At 00:00 UTC on September 20, the Eastern Pacific Hurricane Center (EPHC) took over responsibility for issuing advisories while Greta was 30miles from the coast. Soon after, the depression emerged over the warm waters of the eastern Pacific and re-intensified. At 06:00 UTC, the depression re-attained tropical storm status and named Olivia by the EPHC. After initially moving to the north, Olivia began executing a slow counterclockwise loop. Based on observations from nearby ships and radar, it is estimated Olivia attained minimal hurricane status early on September 22. While tracking towards the Mexican coastline, the system weakened below hurricane threshold; between 19:00 and 20:00 UTC, Olivia made landfall about 60miles east of Salina Cruz. Early on September 23, Olivia dissipated over the Mexican state of Chiapas.[10]

Hurricane Greta–Olivia was a rare crossover storm from the Atlantic to the Pacific, one of only fourteen named storms to maintain tropical cyclone status during the crossing.[7] [11]

Impact

Early in its duration, Greta produced heavy rainfall in the Netherlands Antilles, but the strongest winds remained north of the island.[1]

Late on September 17 when Greta's eye was just offshore Honduras, the country's government issued a hurricane warning for the eastern coastline. Around the same time, the Mexican government issued a hurricane warning for the eastern Yucatán peninsula,[12] and on September 18 a hurricane warning was issued for the Belize and Guatemala coastlines.[13] These advanced warnings helped reduce fatalities.[9] In Puerto Castilla, Honduras, about 2,000 people were evacuated in advance of the storm.[14] The Honduran government put its military, police, and Red Cross on standby in advance of the storm, due to fears of a repeat of Hurricane Fifi in 1974.[15] However, unlike Fifi, which caused deadly floods in the region four years prior and took a similar track, Greta did not cause as significant river flooding in Honduras.[5] [4]

Across much of Greta's track in Central America, the hurricane dropped locally heavy rainfall.[9] When Greta passed just offshore northeastern Honduras, it produced sustained winds of 80mph in Puerto Lempira, with gusts to 115mph. Winds along the northern Honduras coast were diminished due to the eyewall passing to the north.[5] In Honduras, meteorologists estimated that upwards of 15inches of rain fell in mountainous regions. Many villages were isolated and communication with them was severely hampered.[16] In Puerto Lempira, roughly 1,500 of the town's 7,000 residents sought refuge in five large structures during the storm.[17] In twelve communities along the coastline, military officials reported that 656 homes were destroyed, of which 278 were in Punta Potuca.[18] In the offshore Bay Islands, the hurricane destroyed 26 houses on Guanaja, where many roofs were lost and several boats were destroyed. On nearby Roatán, about 75% of the houses lost their roofs after experiencing wind gusts of 80mph.[19] There was one death in Honduras,[9] and nationwide, the hurricane damaged about 1,200 homes, washed out roads and bridges, and wrecked coconut and rice crops.[20]

At Greta's final landfall in Belize, the highest sustained winds were 55mph in Belize City,[9] with gusts to 115mph at Dangriga near the landfall location.[21] On the offshore Ambergris Caye, winds reached 60mph, and there was heavy rainfall.[22] On Half Moon Caye, the hurricane damaged the base of a lighthouse and knocked over several coconut trees. Along the Belize Barrier Reef, the hurricane downed palm trees and produced high waves, with significant wave heights of about 33feet along Carrie Bow Caye.[23] On the mainland, storm tides in Dangriga were 6to above normal, which did not cause much flooding.[9] The strong winds destroyed 50 houses there and unroofed a further 75,[8] including damage to the hospital. There were also disruptions to power and water service. About 90% of the grapefruit crop was destroyed, and 50% of the orange crop was lost.[24] Tides were 2to above normal in Belize City,[9] which caused flooding in conjunction with swollen rivers.[24] The United States embassy was flooded with about one foot of mud.[25] There was little damage in the city,[24] although a tornado in Belize City that damaged four houses and flipped over a truck.[26] During the storm, the Belize International Airport was closed.[27] Farther inland, strong winds caused heavy damage at Guanacaste National Park.[28] Damage throughout Belize was estimated at $25 million (1978 USD), and there were four deaths.[9] Three of the deaths were on offshore islands in areas without radios, and the other was due to electrocution.[29]

Aftermath

Following the storm damage in Honduras, the country requested help from the United States. The Tactical Air Command had sent two squadrons to Central America in the middle of 1978, and in response to the request from Honduras, two aircraft delivered over 100000lb of cots, water, and generators; the units also deployed a 13 - person crew who specialized in disaster relief. The aid was distributed by the Military of Honduras.[20]

In late October 1978, the United Methodist Church sent books and other supplies via aircraft to Belize, after a youth group rode out the storm there and desired to help residents.[30] Despite the hurricane damage, the economy of Belize continued to grow after Greta struck, including an increase in banana production.[31]

On account of the damage caused by the hurricane in the Atlantic basin, the name Greta was retired in the spring of 1979 by the regional hurricane committee of the World Meteorological Organization. It will never again be used to name a tropical system in the basin.[32]

See also

Notes and References

  1. Hurricane Greta and Hurricane Olivia Preliminary Report. 1. National Hurricane Center. 2013-12-17. JPG.
  2. John Hope. 1978-09-14. Tropical Cyclone Discussion Tropical Storm Greta. National Hurricane Center. 2013-12-20. JPG.
  3. Paul Hebert. 1978-09-15. Tropical Cyclone Discussion Tropical Storm Greta. National Hurricane Center. 2013-12-20. JPG.
  4. Book: 29. North Atlantic Tropical Cyclones, 1978. Climatological Data: National Summary. January 1978. 1. Miles B. Lawrence. https://books.google.com/books?id=Fi5RAAAAMAAJ&q=%22hurricane+greta%22&pg=PA74. 2013-12-26.
  5. Hurricane Greta and Hurricane Olivia Preliminary Report. 2. National Hurricane Center. 2013-12-20. JPG.
  6. John Hope. 1978-09-20. Tropical Cyclone Discussion Hurricane Greta. National Hurricane Center. 2013-12-20. JPG.
  7. National Hurricane Center. Atlantic hurricane best track (HURDAT version 2). TXT. National Oceanic and Atmospheric Administration. 2013-06-18. 2013-12-20.
  8. Alvin. National Hurricane Center. HWDamage. 1978-09-19. 2013-12-23. JPG.
  9. Hurricane Greta and Hurricane Olivia Preliminary Report. 3. National Hurricane Center. 2013-12-20. JPG.
  10. Monthly Weather Review. 107. 7. Emil B. Gunther, Eastern Pacific Hurricane Center. July 1979. Eastern North Pacific Tropical Cyclones of 1978. 925–926. 10.1175/1520-0493(1979)107<0911:ENPTCO>2.0.CO;2. 1979MWRv..107..911G . free.
  11. Book: Stephen Caparotta. Frequently Asked Questions. Subject: E15) What tropical storms and hurricanes have moved from the Atlantic to the Northeast Pacific or vice versa?. Hurricane Research Division. 2011-05-31. 2013-12-20. http://www.aoml.noaa.gov/hrd/tcfaq/E15.html. etal.
  12. Paul Hebert. 1978-09-17. Hurricane Greta Intermediate Advisory. National Hurricane Center. 2013-12-22. JPG.
  13. Joe Pelissier. 1978-09-18. Hurricane Greta Intermediate Advisory. National Hurricane Center. 2013-12-22. JPG.
  14. News: The Evening Independent. 2013-12-26. Hurricane Greta Loses Strength, Hits Belize on Journey Inland. 1978-09-19. Associated Press.
  15. News: Hurricane Greta Pounds Honduras Coast. 1978-09-18. Associated Press. Kingman Daily Miner. 2013-12-26.
  16. News: Associated Press. Spokane Daily Chronicle. 40. 1978-09-18. 2010-04-26. Greta Downgraded to Tropical Storm.
  17. News: Associated Press. Toledo Blade. 1978-09-17. 2010-04-28. Winds, Rain Pound Honduras As Greta Hits Coast.
  18. News: Associated Press. Eugene Register-Guard. 1978-09-19. 2010-04-28. Hurricane Greta subsides after lashing two nations.
  19. George Singer. National Hurricane Center. HWDamage7. 1978-09-18. 2013-12-25. JPG.
  20. The Patriot . December 1978 . 5 . 12 . Bundles for Bolivia . 2013-12-26 . dead . https://web.archive.org/web/20131227224215/http://www.westover.afrc.af.mil/shared/media/document/AFD-131211-018.pdf . 2013-12-27 .
  21. Miles B. Lawrence. National Hurricane Center. Report from Belize Weather Service. 1978-09-19. 2013-12-23. JPG.
  22. George Singer. National Hurricane Center. HWDamage. 1978-09-18. 2013-12-23. JPG.
  23. Coral Reefs. May 1983. Hindcast hurricane characteristics on the Belize barrier reef. 1. 4. B. Kjerfve. S. P. Dinnel. 203. 10.1007/bf00304416. 1983CorRe...1..203K . 1844072.
  24. George Singer. National Hurricane Center. HWDamage7. 1978-09-19. 2013-12-25. JPG.
  25. 6. March 2007. U.S. Department of State Magazine. A Farewell to Charms. 2013-12-26.
  26. George Singer. National Hurricane Center. HWDamage. 1978-09-18. 2013-12-23. JPG.
  27. George Singer. National Hurricane Center. HWDamage. 1978-09-19. 2013-12-23. JPG.
  28. 44, 47. Lydia Waight. Judy Lumb. Belize Audubon Society. The First Thirty Years. 2013-12-26. 1999-02-20.
  29. Miles Lawrence. National Hurricane Center. HWDamage. 1978-09-23. 2013-12-23. JPG.
  30. News: The Evening Independent. Ann Weldon. Mission of Mercy. 1978-11-11. 2013-12-26.
  31. 4. October 1996. The Development of the Financial System of Belize (1970-1995). Christine Vellos. Nigeli Sosa. Central Bank of Belize. 2013-12-26.
  32. Web site: Tropical Cyclone Naming History and Retired Names. National Hurricane Center. Miami, Florida. April 4, 2024.