Cyclone Gamede
| Intense Tropical Cyclone ( MFR ) | ||||
|---|---|---|---|---|
| Category 3 cyclone ( SSHWS ) | ||||
 |
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| Emergence | February 20, 2007 | |||
| resolution | March 3, 2007 | |||
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Peak wind speed |
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| Lowest air pressure | 935 hPa ( mbar ) | |||
| dead | 2 direct, 1 missing | |||
| Property damage | US $ 26 million (2007) | |||
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Affected areas |
Mascarens | |||
| Season overview: cyclone season in the Southwest Indicator 2006–2007 |
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Cyclone Gamede was one of the wettest cyclones ever . It rained around 5500 mm of precipitation on Réunion in a period of nine days - this corresponds to about ten times the annual amount of precipitation in the Upper Rhine Plain . The seventh tropical cyclone of the cyclone season in the Southwest Indica 2006–2007 formed on February 20 south of Diego Garcia as a tropical depression. This generally migrated to the west and steadily intensified. Gamede passed as an extensive but only moderately strong cyclone northwest of Mauritius and Réunion. The cyclone stayed within a 400 km radius of Réunion for four days before accelerating south and becoming an extra-tropical cyclone south of Madagascar on March 3 .
For a period between three and nine days, Gamede broke the precipitation records set by tropical cyclone Hyacinthe 27 years earlier. The rain caused moderate damage on Réunion. A bridge in the south of the island collapsed in connection with the storm and a woman was swept away by the flood water and was not found. Two people were killed in Mauritius. The name Gamede was proposed to the World Meteorological Organization of South Africa .
Storm course
On February 19, there was convection over a weak but well-defined ground-level circulation center about 1,130 km southeast of Diego Garcia . This quickly formed rain bands and organized itself into a tropical disturbance. The area under an anticyclone therefore experienced slight vertical wind shear and a favorable discharge . A subtropical ridge in the south led the fault quickly westward. Early on February 20, Météo-France (MFR) classified the system as Tropical Depression Ten, and during the day the Joint Typhoon Warning Center issued a Tropical Cyclone Formation Alert because the convection was much better organized. The system continued to intensify, reaching tropical storm status at 0:00 UTC on February 21, and six hours later Météo-France named the system Gamède ; at this time the center was about 785 km south-southwest of Diego Garcia and about 995 km northeast of Rodrigues .
Gamede then intensified rapidly and, according to the JTWC, reached sustained one-minute wind speeds of 140 km / h (75 knots) early on February 22nd. As the cyclone turned in a west-southwest direction, one eye became visible on satellite imagery , and the JTWC classified Gamede as a tropical cyclone, equivalent to Category 1 on the Saffir-Simpson hurricane wind scale . The intensification rate has now decreased somewhat, which is due to the restriction of the discharge. As the responsible Center météorologique régional spécialisé , Météo-France only upgraded to a tropical cyclone on February 23 at 00:00 UTC. and a short time later Gamede moved across the Cargados-Carajos Islands . Subsequently, the outflow became more stable and the JTWC estimated that the cyclone reached sustained one-minute winds of 185 km / h late on February 23 about 250 km northeast of Mauritius. Initially, a further intensification was predicted, however, a slight weakening set in because a nearby altitude trough hindered the outflow.
Cyclone Gamede remained an extensive system, and on February 24 the zone of strong winds southeast of the center extended to a distance of 670 km; later the cyclone passed Réunion at a distance of about 300 km north , making its closest approach to the island. The cyclone stayed within 400 km of Réunion for more than 90 hours, causing persistent heavy rain in the island's mountainous region. Weather radar observations suggest that Gamede maintained an eye 60–70 km in diameter. After the cyclone had moved in a south-westerly direction for several days, a building ridge south of the storm changed its direction of movement to a more west-facing orbit before Gamede remained almost stationary. The cyclone was originally forecast to move further west and hit the coast of Madagascar near Toamasina , but when the cyclone re-intensified it made a small loop before hitting winds of 165 km / h late on February 25th. h reached its greatest strength about halfway between Réunion and Madagascar. In gusts of wind, Gamede reached wind speeds of up to 230 km / h in this phase.
The cyclone then weakened as it remained almost stationary and lost most of its convection due to buoyancy ; Buoyancy is the process by which a stationary system causes the water surface temperature to drop because colder water comes to the surface from below. Gamede remained almost stationary until late on February 26th when it began to move steadily south-southwest, caused by an approaching subtropical trough in the south. On February 28, convection resumed around a re-building eyewall before the system accelerated southward; on March 1st the cyclone lost strength again because the wind shear increased and the water temperatures continuously decreased. Gamede weakened to a tropical storm when its center was separated by deep convection and late on March 1st the storm turned into an extra-tropical system. After the transition, the storm remained in place for almost two days, while wind speeds decreased below storm force. The residual low of Gamede turned west and lasted until it dissolved on March 6th.
Preparations
In Mauritius , around 200 residents sought emergency accommodation because of the cyclone. The island was under cyclone warning level III for 36 hours and a few more hours under warning level IV, the latter meaning that wind gusts of more than 120 km / h occurred or were expected.
Before the storm approached the island, Réunion authorities closed schools and imposed a temporary ban on driving. Because of the impending storm, several flights to and from Mauritius, Réunion and Rodrigues were canceled.
Impact and records
| Duration (hours) |
Storm name and year |
Record before Gamede |
Value for Gamede |
+/- (in mm) |
|---|---|---|---|---|
| mm | mm | |||
| 24 | Denise (1966) | 1825 | 1625 | −200 |
| 48 | Unnamed (1958) | 2467 | 2463 | −4 |
| 72 | Hyacinthe (1980) | 3240 | 3929 | +689 |
| 96 | Hyacinthe (1980) | 3551 | 4869 | +1318 |
| All in all | Hyacinthe (1980) | 5678 | 5512 | −166 |
At noon on February 23, cyclone Gamede passed over the Cargados-Carajos Islands, where an air pressure of 960 hPa was measured.
The cyclone affected Mauritius on February 25th . The power supply was cut for 70% of the island's population, and some minor damage to the infrastructure was also reported. Agriculture was also affected. Despite warnings from authorities to stay inside, several people were outside during the cyclone. Gamede killed two people in Mauritius, one of whom drowned in the high waves.
The enormous size of the cyclone led to persistent, very heavy rainfall over several days in the Réunions mountains. The island is the site of several tropical rainfall records; Due to the orography of the island, the moisture must rise to the volcanic peaks, which leads to their cooling and therefore to rain. The heaviest rainfall occurred between February 24th and 28th. At the Cratère Commerson , located at an altitude of around 2300 m, 2463 mm of precipitation was measured in a 48-hour period, which is just below the record value of an unnamed tropical cyclone in April 1958. Gamede broke the world record for precipitation between three and nine days; the total storm-related rainfall at Cratère Commerson totaled 5,512 mm; However, cyclone Hyacinthe of 1980 remains the wettest tropical cyclone ever, as it generated larger amounts of rain within ten days. Several measuring stations on the island reported very high amounts of rain within 24 hours; Hell-Bourg reported 1489 mm. In a 72-hour span, 2321 mm was measured in Cilaos . A top gust of 205 km / h was recorded on the island.
On Réunion, the passage of the cyclone interrupted the supply of electricity and water for around 80,000 households. The rain caused some flood damage on Réunion, especially the combination of precipitation and strong winds causes severe damage to the sugar cane and banana harvest . Several roads and bridges on the island were damaged. A 520 m long bridge over the Rivière Saint-Étienne near Saint-Louis collapsed; the property damage caused by Gamede was estimated at 20 million euros . A woman was washed away in her car and was no longer found alive. Nine people on the island were injured by the effects of the storm, two of them seriously.
On June 13, 2007, the French government made available 17.6 million euros, including 7.7 million euros for the repair of roads and infrastructure, including the rebuilding of the destroyed bridge over the Rivière Saint-Étienne, and 9.6 million for through farmers damaged by the cyclone.
Strong waves and winds also affected the Spirit of Adventure cruise ship east of Madagascar; several windows were broken, but no serious injuries occurred. Gamede generated thunderstorms and gusts of wind on the east coast of Madagascar.
Gamede closely followed the tropical cyclones Bondo, Clovis and Favio and was the fourth cyclone to impact Madagascar in two months.
Individual evidence
- ^ World Meteorological Organization: Seventeenth Session of the RA I Tropical Cyclone Committee for the South-West Indian Ocean (PDF; 6.0 MB) 2005. Retrieved October 20, 2010.
- ↑ Bravo Forecasting Team: February 19 Significant Tropical Weather Outlook ( English ) 2007. Accessed on October 20, 2010. ( Page no longer available , search in web archives )
- ↑ a b c d e Météo-France La Réunion: Cyclone tropical intense: Gamède (Période du 19/02/2007 au 06/03/2007) ( French ) 2007. Accessed October 20, 2010.
- ↑ Bravo Forecasting Team: February 20 Significant Tropical Weather Outlook ( English ) 2007. Accessed on October 20, 2010. ( Page no longer available , search in web archives ) Info: The link was automatically marked as broken. Please check the link according to the instructions and then remove this notice.
- ↑ a b c d e f g h Gary Padgett: February 2007 Worldwide Tropical Cyclone Summary ( English ) 2007. Retrieved on October 20 of 2010.
- ↑ Bravo Forecasting Team: February 20 Significant Tropical Weather Outlook (2) ( English ) 2007. Accessed on October 20, 2010. ( Page no longer available , search in web archives )
- ^ Météo-France: Tropical Storm Gamede Advisory Four ( English ) 2007. Accessed on October 20, 2010. ( Page no longer available , search in web archives )
- ↑ a b c d e Joint Typhoon Warning Center: advisories on Tropical Cyclone Gamede ( English ) 2007. Accessed on 20 February, 2008.
- ^ Météo-France: Severe Tropical Storm Gamede Advisory Nine ( English ) 2007. Accessed on October 20, 2010. ( Page no longer available , search in web archives )
- ^ Météo-France: Tropical Cyclone Gamede Advisory Eleven ( English ) 2007. Accessed on April 10, 2008. ( Page no longer available , search in web archives )
- ↑ Météo-France: Tropical Cyclone Gamede Advisory Eighteen ( English ) 2007. Accessed on October 20, 2010. ( Page no longer available , search in web archives )
- ^ Météo-France: Tropical Cyclone Gamede Advisory Twenty ( English ) 2007. Accessed on April 10, 2008. ( Page no longer available , search in web archives )
- ↑ Integrated Regional Information Networks: Fourth tropical cyclone in four months, nears the coast ( English ) March 13, 2007. Retrieved October 20, 2010.
- ^ Météo-France: Tropical Cyclone Gamede Advisory Twenty-Two . 2007. Accessed on October 20, 2010. ( Page no longer available , search in web archives ) Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice.
- ^ Météo-France: Tropical Cyclone Gamede Advisory Thirty-Three ( English ) 2007. Accessed on October 20, 2010. ( Page no longer available , search in web archives )
- ^ Météo-France: Tropical Cyclone Gamede Advisory Thirty-Six ( English ) 2007. Accessed on October 20, 2010. ( Page no longer available , search in web archives )
- ^ Météo-France: Tropical Cyclone Gamede Advisory Thirty-Seven ( English ) 2007. Accessed on October 20, 2010. ( Page no longer available , search in web archives )
- ↑ a b c d e Africa Weekly Spotlight (PDF) International Strategy for Disaster Reduction. March 5, 2007. Retrieved October 20, 2010.
- ^ A b Africa News: Legislation Needed to Force People Inside During Cyclones . February 28, 2007. Retrieved April 13, 2008.
- ↑ Mauritius Meteorological Service: Classification of Tropical Cyclones in the South-West Indian Ocean ( English ) 2008. Archived from the original on April 23, 2008. Retrieved April 13, 2008.
- ↑ a b c d e Sapa: Cyclone Gamede sweeps over Indian Ocean islands , Agence France-Presse. February 25, 2007. Archived from the original on May 23, 2012 Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. . Retrieved October 20, 2010.
- ↑ Le Mauricien: Gamede comeback disrupts operations at airport . February 27, 2007.
- ↑ a b c Météo-France: Avec GAMEDE et 27 ans après HYACINTHE, La Réunion bat ses propres records mondiaux de précipitations sur les durées de 3 à 9 jours ( French ) 2007. Archived from the original on March 22, 2007. Retrieved on 12 April 2008.
- ↑ Paul Simons: Tropical rainfall Provides a reunion to remember (English) , The Times. March 19, 2007. Retrieved October 20, 2010.
- ^ A b Associated Press: Cyclone cuts off water, electricity for many on Reunion Island ( English ) February 26, 2007. Retrieved October 20, 2010.
- ↑ Maire Info: 7.7 millions d'euros contribueront à la réparation des dégâts aux infrastructures essentielles des collectivités territoriales ( French ) June 15, 2007. Accessed October 20, 2010.
- ^ David Sanderson: Cruise liner stranded in remote port by cyclone (English) , The Times Online. March 5, 2007. Retrieved October 20, 2010.
- ↑ Africa: Weather Hazards Assessments for 1-7 March 2007 ( English ) Famine Early Warning System Network. February 28, 2007. Retrieved October 20, 2010.
- ↑ Madagascar: Fifth Cyclone Hits Island Bulletin no. 1/2007 ( English ) International Federation of Red Cross and Red Crescent Societies . March 17, 2007. Retrieved January 28, 2008.
