Hurricane Allen

Infobox Hurricane
Name=Hurricane Allen
Type=hurricane
Year=1980
Basin=Atl
Image location=AllenPeakNew.jpg

Yucatán Channel near peak intensity on August 7, 1980
Formed=July 31, 1980
Dissipated=August 11, 1980
1-min winds=165
Pressure=899
Da

Inflated=1
Fatalities=236 – 261 direct [http://www.nhc.noaa.gov/pastdeadlyapp1.shtml]
Areas=Windward Islands, Haiti, Jamaica, Yucatán Peninsula, northern Mexico, southern Texas
Hurricane season=1980 Atlantic hurricane season

Hurricane Allen was the strongest hurricane of the 1980 Atlantic hurricane season. It was one of the strongest hurricanes in recorded history, one of the few hurricanes to reach Category 5 status on the Saffir-Simpson Hurricane Scale on three separate occasions, and spent more time as a Category 5 than any other Atlantic hurricane. Allen is the second of only two hurricanes in the recorded history of the Atlantic basin to achieve sustained winds of convert|190|mph|km/h|abbr=on, after Hurricane Camille in 1969.

Meteorological history

Allen originated as a Cape Verde-type hurricane, a rarity for tropical systems in early August. The tropical disturbance which would become Allen moved off the coast of Africa on July 30, and was upgraded to a tropical depression on August 1. Early on August 2, as it moved towards the Caribbean it became the first named storm of the season-Tropical Storm Allen. Allen moved westward at an unusually high speed of convert|15|to|20|kn|km/h, rapidly intensifying into a Category 5 hurricane at 0000 (GMT) on August 5 while south of Puerto Rico and (very unusually) remaining so for over a day. During this time Allen attained a central pressure of convert|911|mbar|inHg|abbr=on|lk=off, the lowest pressure on record in the Eastern Caribbean. The eye passed just south of Hispaniola and just north of Jamaica as a Category 4 hurricane.After weakening from interactions with the mountains of Haiti and Jamaica, Allen reintensified to a Category 5 for a second time, again retaining this intensity for over a day. It moved between Cuba and the Yucatán Peninsula, reaching its minimum pressure of 899mb while crossing the Yucatán Channel. Interestingly, during Allen's trek through the Caribbean Sea and the Gulf of Mexico, its center of circulation never crossed over land despite its close passage to the islands of the Caribbean.Allen again weakened to a Category 4 storm through interactions with land, but it restrengthened into a Category 5 hurricane for a third time as it moved over the warm waters of the Gulf of Mexico, again keeping this intensity for nearly a full day and with a pressure drop to convert|909|mbar|inHg|abbr=on|lk=off, the lowest pressure ever recorded in the western Gulf of Mexico. Shortly before landfall, dry air aloft in the Gulf caused the massive storm to weaken substantially. Allen made landfall north of Brownsville, Texas as a Category 3 storm with sustained winds of 115 mph.

Records

When Allen reached Category 5 intensity on August 5, it became the earliest Category 5 storm ever recorded. This record stood until Hurricane Emily shattered it on July 16, 2005.Allen is one of three Atlantic hurricanes to reach Category 5 on the Saffir-Simpson hurricane scale on three separate occasions, the others being Hurricane Ivan and Hurricane Isabel.

Allen also produced the fifth-lowest minimum pressure ever recorded in the Atlantic basin at 899 mbar (hPa) and was the strongest known hurricane in the basin, in terms of pressure, since 1935. Until then, it was the second strongest hurricane by pressure in the Atlantic Basin, but was since pushed down to 5th, and no hurricane has ever achieved 190 mph winds in this basin since then. [NOAA. [http://www.weather.gov/om/assessments/pdfs/Katrina.pdf Hurricane Katrina Service Assessment.] Retrieved on 2007-04-13.] It remains the most intense storm ever in August.

Allen spent nearly 3 days as a Category 5 storm, by far the highest of any Atlantic hurricane, and the third longest lasting category 5 storm on record, behind two typhoons (Karen and Nancy) in the early 1960s.

Impact

Allen caused $2.6 billion (2005 USD) in damages and killed at least 274 people throughout its course (including indirect deaths).cite web|title=Hurricane Allen Tropical Cyclone Report|Publisher=National Hurricane Center|accessdate = 2006-05-19|url=http://www.nhc.noaa.gov/archive/storm_wallets/atlantic/atl1980-prelim/allen/]

Caribbean islands

In Barbados, preliminary damages were estimated to be $1.5 million (1980 USD). About 500 houses were either damaged or destroyed. No deaths were reported. St. Lucia sustained heavy damage from Allen. Eighteen people lost their lives as a result of the storm's passage. One death in Guadeloupe was attributed to Allen.Fact|date=September 2008. The hurricane also divided the Isla de Aves of Venezuela into two smaller islets.

In the central Caribbean, Cayman Brac was hit by winds in excess of convert|115|mi/h|km/h|abbr=on which caused considerable property damage. Eight deaths in Jamaica were attributed to Allen. Damage was very significant along the northeast coast, where the hurricane made its closest approach to the island. Also, though there were no reports of significant property damage in Cuba, 3 deaths were attributed to Allen.Fact|date=September 2008

Extensive damage occurred in Haiti due to high winds and flash flooding. Total costs for that country were estimated to be at more than $400 million (1980 USD). Roughly 50% of the nation's coffee crop was destroyed. In all, 220 people were killed and 835'000 were left homeless. In Port-au-Prince, 41 deaths were caused by tin roofs flying off and around 1200 were made homeless by flooding [Hurricanecity. [http://www.hurricanecity.com/city/portauprince.htm Port au prince,Haiti's history with tropical systems.] Retrieved on 2007-04-13.] .

Mexico

United States

In Texas, the storm surge was reported as high as convert|12|ft|m at Port Mansfield, though it may have been higher because the highest surges occurred in unpopulated and unmonitored sections of the Texas coast. A peak wind gust of convert|129|mi/h|km/h|abbr=on was also measured at Port Mansfield. The storm caused 7 deaths in Texas and 17 in Louisiana (most resulting from the crash of a helicopter evacuating workers from an offshore platform). Allen spawned several tornadoes in Texas. One tornado caused $100 million in damage when it hit Austin, Texas, making it the costliest tropical cyclone-spawned tornado in recorded history. Overall, however, the storm caused limited damage in the United States due to its suddenly diminished power and because its highest tides and winds hit a sparsely-populated portion of the Texas coast.

One bit of good news resulted from Allen's arrival -- it dumped 10 to convert|20|in|mm of rain in south Texas, ending a summer-long drought during the Heat Wave of 1980. Its storm total rainfall map is shown to the right.cite web | title="NOAA HPC - Hurricane Allen"|url=http://www.hpc.ncep.noaa.gov/tropical/rain/allen1980.html]

Retirement

Because of the destruction, extreme death tolls and intensity, the name Allen was retired from the Atlantic tropic storms list in the spring of 1981, and will never be used again for a future Atlantic hurricane. It was replaced with Andrew in the 1986 season although that was retired after the 1992 storm because of "its" destruction in southeastern Florida and Louisiana and replaced by Alex for the 1998 Season, which remains in use today and will next be used in the 2010 season.

ee also

*List of tropical cyclones
*List of Atlantic hurricanes
*List of Category 5 Atlantic hurricanes

References

Further reading

*Cite journal |last=Marks |first=Frank D. |coauthors= |year=1985 |title=Evolution of the Structure of Precipitation in Hurricane Allen (1980) |journal=Monthly Weather Review |volume=113 |issue=6 |pages=909–930 |url= |issn= |doi=10.1175/1520-0493(1985)113<0909:EOTSOP>2.0.CO;2

External links

* [http://www.srh.noaa.gov/crp/docs/research/hurrhistory/Allen/allen.html National Weather Service - Hurricane Allen]
* [http://ams.allenpress.com/perlserv/?request=get-abstract&doi=10.1175%2F1520-0485(1983)013%3C0117:TWOHAI%3E2.0.CO%3B2 The Wake of Hurricane Allen in the Western Gulf of Mexico]
* [http://www.wind.ttu.edu/Pubs/pdfs/D8-10-80%20Hurr%20Allen.pdf Effects of Hurricane Allen on Buildings and Coastal Construction]
* [http://www.csc.noaa.gov/hes/images/pdf/HURR_ALLEN80_MET_DATA.pdf Pertinent Meteorological Data for Hurricane Allen of 1980]