Hurricane Greta-Olivia

Infobox Hurricane
Name=Hurricane Greta-Olivia
Type=hurricane
Year=1978
Basin=Atl
Image location=Hurricane_Greta_1978.jpg

Gulf of Honduras
Formed=September 13, 1978
Dissipated=September 23, 1978
1-min winds=116
Pressure=947
Da

Inflated=1
Fatalities=5 direct
Areas=Honduras, Belize, Guatemala, Mexico
Hurricane season=1978 Atlantic hurricane season, 1978 Pacific hurricane season

Hurricane Greta-Olivia was a Category 4 hurricane that crossed over Central America, changing names upon reaching the Eastern Pacific during the 1978 Atlantic hurricane season and 1978 Pacific hurricane season. Greta threatened to reproduce the devastating effects of Hurricane Fifi just four years prior, but the hurricane only caused 5 deaths. It is rare for a hurricane to cross over into another ocean basin, as Greta was one of the very few that have done so.

Meteorological history

Hurricane Greta

A tropical wave exited the coast of Africa near Dakar, Senegal on September 7. It moved westward, remaining disorganized until an increase of convection occurred on the 10th. The wave continued to organize as it passed through the Lesser Antilles, and based on ship and land reports, the wave was upgraded to a tropical depression on September 13 while 75 miles west-northwest of Trinidad. Though located in a climatologically unfavorable area, the depression intensified, and reached tropical storm status on the 14th.

A strong trough ahead of Greta prevented significant strengthening as it moved westward across the Caribbean Sea. However, warm water temperatures allowed it to steadily intensify to reach hurricane status on September 16 while south of Jamaica. The trough weakened considerably on the 17th, and enabled Greta to quickly intensify as it approached the Honduras coastline. The unique topography of the coastline allowed for Greta to reach peak winds of 135 mph near land.

Hurricane Greta made its Honduras landfall on September 18 at Category 4 status. Rather than continuing westward, the center ricocheted off the coast, and spared the Honduran mainland from its eyewall. Moving west-northwestward through the Gulf of Honduras, land interaction weakened the hurricane. On September 19, Hurricane Greta made landfall on the Stann Creek District in southern Belize, and weakened rapidly to a tropical depression over land. A high pressure system to its north forced it to the southwest, where, upon reaching the Eastern Pacific, its circulation remained intact.

Hurricane Olivia

The depression moved into the Eastern Pacific from the Chiapas province of southeast Mexico. It moved to the southwest, and was renamed Tropical Storm Olivia on September 20. It remained nearly stationary, and slowly looped back to the north. Olivia reached hurricane status on the 22nd, but weakened just offshore of Mexico to a tropical storm. The storm turned to the northeast, and hit Oaxaca late on the 22nd, and dissipated the next day over land.

Comparisons to other storms

Based on its strength and westward track through the western Caribbean Sea, Greta was feared to repeat the devastating effects of Hurricane Fifi in 1974. However, Greta failed to produce the devastating river floods. In addition, because Greta was a compact storm that remained offshore, damage was reduced to a minimal.

Hurricane Greta was a rare Atlantic Ocean to Eastern Pacific cross-over storm. It was one of only six known storms to move from the Atlantic to the Pacific.

Impact

While passing through the Lesser Antilles and the islands of the southeast Caribbean, they received some moderate rainfall, but much of the convection was located to the north.

As said earlier, Greta did not produce the severe river flooding that Fifi caused. Minor flooding was observed in Honduras, and what little damage that occurred there was in the extreme northeast portion of the country. In Belize, tides were 6 feet above normal in some locations, with damage estimated at $25 million (1978 USD) due to the direct hit. Improved warnings by the governments of Honduras, Belize, and their neighbors reduced the death toll to five, with one person death in Honduras and four casualties (with three missing) in Belize.

Damage estimates for Mexico from Olivia do not exist, and is likely to be low due to its weak nature.

Lack of retirement

The name Greta was not retired. However, the name has not been used since, due to a change in the list of hurricane names that began in 1979.

See also

* List of tropical cyclones
* List of Atlantic hurricanes

References

* [ftp://ftp.nhc.noaa.gov/pub/storm_archives/atlantic/prelimat/atl1978/greta/ NHC Greta report]
* [http://www.aoml.noaa.gov/hrd/tcfaq/E15.html Atlantic/Pacific cross-over Storms]
* [http://www.weather.unisys.com/hurricane/atlantic/1978/GRETA/track.dat Greta Best Track]
* [http://www.weather.unisys.com/hurricane/e_pacific/1978/OLIVIA/track.dat Olivia Best Track]