2005-06 South-West Indian Ocean cyclone season
Encyclopedia
The 2005–06 South-West Indian Ocean cyclone season was an annual event of tropical cyclone
formation. It started on November 15, 2005 and ended on April 30, 2006, with the exception for Mauritius
and the Seychelles
, for which it continued until May 15. These dates conventionally delimit the period of each year when most tropical cyclones form in the basin, which is west of 90°E
and south of the Equator
. Tropical cyclones in this basin are monitored by the Regional Specialised Meteorological Centre in Réunion
.
on October 12. It became more organised and the JTWC upgraded it to a Tropical Cyclone with a peak intensity of 35kt between October 14 and October 15. The system never reached Tropical Storm strength based on Météo France's advisories. Due to growing wind shear
, the system dissipated over water on October 15.
issued a gale warning on a Tropical Low near 8.3°S 97.1°E on November 5. According to JTWC, the low developed into a tropical cyclone and reached its peak intensity of 45kt on the same day. It moved southwestward into Météo France (Réunion
)'s area of Responsibility on November 7 and gradually weakened afterwards. The last JTWC warning was released the next day. Météo France tracked its remnants until November 9.
- on the same day. Alvin weakened significantly afterwards and the last JTWC warning was released on November 26. Météo France tracked its remnants until November 30.
)'s area of responsibility on December 23. During its long journey to the west, it became more organised and JTWC upgraded it to a Tropical Cyclone with peak intensity of 35kt between December 24 and December 25. The system then skirted east of Réunion
as a zone of disturbed weather. Météo France tracked its remnants until December 30.
on January 5. The system tracked along the southern coast of Mozambique and became extratropical on January 8. The depression caused torrential rains in Mozambique and swept away 26 people.http://allafrica.com/stories/200601060200.html
and reorganized. The system strengthened into a Severe Tropical Storm again on February 2, and strengthened further into a tropical cyclone. Operationally 08R was carried as a 90kt intense tropical cyclone but was downgraded following further analysis. Boloetse passed just southwest of Madagascar on February 4 and became extratropical on February 5.
and became more organized. On February 19, it was designated as Tropical Disturbance 09. The midget system quickly strengthened but its status was under dispute. Météo France upgraded it to a moderate tropical storm while JTWC classified it as a Tropical Storm equivalent. In contrast, Mauritius
did not upgrade and name the system. In post-analysis, Météo France upgraded it further to a severe tropical storm. Since the satellite era, it is rare to have an unnamed severe tropical storm in any part of the world other than north Indian Ocean. The storm was short-lived, it rapidly weakened on February 20 and dissipated over water on February 23.
at 1800 UTC February 23. The name was contributed by Mauritius. Carina moved southwards, and became a tropical cyclone on February 26. Carina remained over open waters and quickly intensified, becoming an intense tropical cyclone on February 27. At 0000Z Feb 28, Carina was moving west-southwest and nearing Category 5 strength on the Saffir-Simpson hurricane scale
. Carina moved into an area with high wind shear on February 28, started to weaken on March 3. The remnants made an anti-clockwise loop and resumed a westerly track on before finally dissipated on March 10.
identified a broad area of low pressure between 45°E
and 55°E
and from 8°S
to 15°S
. Within this area, two lows were detected. The main one (11R) was north of Mascarnes Islands while the other one was north of Madagascar.
11R became a tropical depression on March 3 and was later named Diwa. The name was contributed by Malawi. At first Diwa was classified as a moderate tropical storm by Mauritius, but as a tropical depression by Météo France, but a few hours later, Météo France also classified it as a tropical storm. This made the fourth documented case of a tropical cyclone being named before reaching tropical storm strength.
On the other hand, the other low briefly developed into a tropical disturbance (12R) on March 4. The two systems were less than 700 km away and Météo France said that Diwa might be partially influenced by a slight Fujiwhara effect
with 12R. 12R was short-lived and Diwa remained the dominant system. Diwa came very near to Réunion
but never made landfall. The outer edges of Diwa did caused some substantial rainfall on the island. The strongest gust reported was 194 km/h at the top of the Sainte-Rose Large-Piton. The highest rainfall in three days was 2720 mm in Commerson. After this, Diwa moved southwards and strengthened into a severe tropical storm on March 7. Eventually, Diwa became extratropical and reached its peak intensity on March 9.
, then the Sub-regional Tropical Cyclone Advisory Centre in Madagascar
assigns the appropriate name to the storm. If a tropical disturbance reaches moderate tropical storm status between 55°E
and 90°E
, then the Sub-regional Tropical Cyclone Advisory Centre in Mauritius
assigns the appropriate name to the storm. A new annual list is used every year so no names are retired.
Tropical cyclone
A tropical cyclone is a storm system characterized by a large low-pressure center and numerous thunderstorms that produce strong winds and heavy rain. Tropical cyclones strengthen when water evaporated from the ocean is released as the saturated air rises, resulting in condensation of water vapor...
formation. It started on November 15, 2005 and ended on April 30, 2006, with the exception for Mauritius
Mauritius
Mauritius , officially the Republic of Mauritius is an island nation off the southeast coast of the African continent in the southwest Indian Ocean, about east of Madagascar...
and the Seychelles
Seychelles
Seychelles , officially the Republic of Seychelles , is an island country spanning an archipelago of 115 islands in the Indian Ocean, some east of mainland Africa, northeast of the island of Madagascar....
, for which it continued until May 15. These dates conventionally delimit the period of each year when most tropical cyclones form in the basin, which is west of 90°E
90th meridian east
The meridian 90° east of Greenwich is a line of longitude that extends from the North Pole across the Arctic Ocean, Asia, the Indian Ocean, the Southern Ocean, and Antarctica to the South Pole.The Ninety East Ridge is named after the meridian....
and south of the Equator
Equator
An equator is the intersection of a sphere's surface with the plane perpendicular to the sphere's axis of rotation and containing the sphere's center of mass....
. Tropical cyclones in this basin are monitored by the Regional Specialised Meteorological Centre in Réunion
Réunion
Réunion is a French island with a population of about 800,000 located in the Indian Ocean, east of Madagascar, about south west of Mauritius, the nearest island.Administratively, Réunion is one of the overseas departments of France...
.
Tropical Disturbance 01R
Formed on September 5 and dissipated on September 6, 2005.- Tropical Cyclone Database's storm summary and track file for 01R
Tropical Depression 02R
Tropical Disturbance 02R formed approximately 860 nautical miles (1,590 km) east of Diego GarciaDiego Garcia
Diego Garcia is a tropical, footprint-shaped coral atoll located south of the equator in the central Indian Ocean at 7 degrees, 26 minutes south latitude. It is part of the British Indian Ocean Territory [BIOT] and is positioned at 72°23' east longitude....
on October 12. It became more organised and the JTWC upgraded it to a Tropical Cyclone with a peak intensity of 35kt between October 14 and October 15. The system never reached Tropical Storm strength based on Météo France's advisories. Due to growing wind shear
Wind shear
Wind shear, sometimes referred to as windshear or wind gradient, is a difference in wind speed and direction over a relatively short distance in the atmosphere...
, the system dissipated over water on October 15.
Tropical Depression 03R
Formed on November 6 and dissipated on November 8, 2005.- Tropical Cyclone Database's storm summary and track file for 03R
Tropical Depression 04R
TCWC PerthPerth, Western Australia
Perth is the capital and largest city of the Australian state of Western Australia and the fourth most populous city in Australia. The Perth metropolitan area has an estimated population of almost 1,700,000....
issued a gale warning on a Tropical Low near 8.3°S 97.1°E on November 5. According to JTWC, the low developed into a tropical cyclone and reached its peak intensity of 45kt on the same day. It moved southwestward into Météo France (Réunion
Réunion
Réunion is a French island with a population of about 800,000 located in the Indian Ocean, east of Madagascar, about south west of Mauritius, the nearest island.Administratively, Réunion is one of the overseas departments of France...
)'s area of Responsibility on November 7 and gradually weakened afterwards. The last JTWC warning was released the next day. Météo France tracked its remnants until November 9.
Intense Tropical Cyclone Bertie-Alvin
TCWC Perth issued a gale warning on a Tropical Low near 3.5°S 94.0°E, which later became Bertie on November 17. Bertie gradually strengthened and became a Severe Tropical Cyclone on November 21, before entering the Southwest Indian Ocean on November 23 and being renamed Alvin. According to the JTWC, the cyclone reached its peak intensity of 115 knots (210 km/h) - which equates to a marginal Category 4 on the Saffir-Simpson hurricane scaleSaffir-Simpson Hurricane Scale
The Saffir–Simpson Hurricane Scale , or the Saffir–Simpson Hurricane Wind Scale , classifies hurricanes — Western Hemisphere tropical cyclones that exceed the intensities of tropical depressions and tropical storms — into five categories distinguished by the intensities of their sustained winds...
- on the same day. Alvin weakened significantly afterwards and the last JTWC warning was released on November 26. Météo France tracked its remnants until November 30.
- Météo France's archive on the system, in French.
- Archive for Bertie-Alvin from the Tropical Cyclone Center Database.
- Tropical Cyclone Database's storm summary and track file for 03S (05R)
Tropical Depression 06R
TCWC Perth issued a gale warning on a Tropical Low near 9.5°S 91.9°E on December 22. Moving west-southwestward, the low entered Météo France (RéunionRéunion
Réunion is a French island with a population of about 800,000 located in the Indian Ocean, east of Madagascar, about south west of Mauritius, the nearest island.Administratively, Réunion is one of the overseas departments of France...
)'s area of responsibility on December 23. During its long journey to the west, it became more organised and JTWC upgraded it to a Tropical Cyclone with peak intensity of 35kt between December 24 and December 25. The system then skirted east of Réunion
Réunion
Réunion is a French island with a population of about 800,000 located in the Indian Ocean, east of Madagascar, about south west of Mauritius, the nearest island.Administratively, Réunion is one of the overseas departments of France...
as a zone of disturbed weather. Météo France tracked its remnants until December 30.
Tropical Disturbance 07R
A zone of disturbed weather developed on December 29. Moving southwestwards, it became an overland depression with maximum sustained winds of 25kt in MozambiqueMozambique
Mozambique, officially the Republic of Mozambique , is a country in southeastern Africa bordered by the Indian Ocean to the east, Tanzania to the north, Malawi and Zambia to the northwest, Zimbabwe to the west and Swaziland and South Africa to the southwest...
on January 5. The system tracked along the southern coast of Mozambique and became extratropical on January 8. The depression caused torrential rains in Mozambique and swept away 26 people.http://allafrica.com/stories/200601060200.html
- Archive for 07R from the Tropical Cyclone Center Database.
Tropical Cyclone Boloetse
A zone of disturbed weather developed northeast of Madagascar on January 20. The system organized into a Tropical Depression on January 24 and further intensified into Moderate Tropical Storm Boloetse on 25 January. The name was contributed by Lesotho. On 26 January, Boloetse briefly became a severe tropical storm with maximum sustained winds 50kt (92 km/h) near center. On January 29, Tropical Storm Boloetse crossed the coast near the village of Mananjary. On January 30, its remnants emerged into Mozambique ChannelMozambique Channel
The Mozambique Channel is a portion of the Indian Ocean located between the island nation of Madagascar and southeast Africa, primarily the country of Mozambique. It was a World War II clashpoint during the Battle of Madagascar...
and reorganized. The system strengthened into a Severe Tropical Storm again on February 2, and strengthened further into a tropical cyclone. Operationally 08R was carried as a 90kt intense tropical cyclone but was downgraded following further analysis. Boloetse passed just southwest of Madagascar on February 4 and became extratropical on February 5.
- Météo France's archive on the system, in FrenchFrench languageFrench is a Romance language spoken as a first language in France, the Romandy region in Switzerland, Wallonia and Brussels in Belgium, Monaco, the regions of Quebec and Acadia in Canada, and by various communities elsewhere. Second-language speakers of French are distributed throughout many parts...
. - Archive for Boloetse from the Tropical Cyclone Center Database.
- More info here
Severe Tropical Storm 09R
A tropical disturbance formed just west of Madagascar on February 15. It moved south-east, towards MauritiusMauritius
Mauritius , officially the Republic of Mauritius is an island nation off the southeast coast of the African continent in the southwest Indian Ocean, about east of Madagascar...
and became more organized. On February 19, it was designated as Tropical Disturbance 09. The midget system quickly strengthened but its status was under dispute. Météo France upgraded it to a moderate tropical storm while JTWC classified it as a Tropical Storm equivalent. In contrast, Mauritius
Mauritius
Mauritius , officially the Republic of Mauritius is an island nation off the southeast coast of the African continent in the southwest Indian Ocean, about east of Madagascar...
did not upgrade and name the system. In post-analysis, Météo France upgraded it further to a severe tropical storm. Since the satellite era, it is rare to have an unnamed severe tropical storm in any part of the world other than north Indian Ocean. The storm was short-lived, it rapidly weakened on February 20 and dissipated over water on February 23.
- Météo France's archive on the system, in FrenchFrench languageFrench is a Romance language spoken as a first language in France, the Romandy region in Switzerland, Wallonia and Brussels in Belgium, Monaco, the regions of Quebec and Acadia in Canada, and by various communities elsewhere. Second-language speakers of French are distributed throughout many parts...
. - Archive for 12S from the Tropical Cyclone Center Database.
Intense Tropical Cyclone Carina
Tropical depression 10R (14S) formed far southeast of Diego Garcia on February 23. It became more organized and was upgraded to Moderate Tropical Storm Carina by RéunionRéunion
Réunion is a French island with a population of about 800,000 located in the Indian Ocean, east of Madagascar, about south west of Mauritius, the nearest island.Administratively, Réunion is one of the overseas departments of France...
at 1800 UTC February 23. The name was contributed by Mauritius. Carina moved southwards, and became a tropical cyclone on February 26. Carina remained over open waters and quickly intensified, becoming an intense tropical cyclone on February 27. At 0000Z Feb 28, Carina was moving west-southwest and nearing Category 5 strength on the Saffir-Simpson hurricane scale
Saffir-Simpson Hurricane Scale
The Saffir–Simpson Hurricane Scale , or the Saffir–Simpson Hurricane Wind Scale , classifies hurricanes — Western Hemisphere tropical cyclones that exceed the intensities of tropical depressions and tropical storms — into five categories distinguished by the intensities of their sustained winds...
. Carina moved into an area with high wind shear on February 28, started to weaken on March 3. The remnants made an anti-clockwise loop and resumed a westerly track on before finally dissipated on March 10.
- Météo France's archive on the system, in FrenchFrench languageFrench is a Romance language spoken as a first language in France, the Romandy region in Switzerland, Wallonia and Brussels in Belgium, Monaco, the regions of Quebec and Acadia in Canada, and by various communities elsewhere. Second-language speakers of French are distributed throughout many parts...
. - Archive for Carina from the Tropical Cyclone Center Database.
Severe Tropical Storm Diwa
On March 2, Météo FranceMétéo-France
Météo-France is the French national meteorological service.The organisation was established by decree in June 1993 and is a department of the Ministry of Transportation. It is headquartered in Paris but many domestic operations have been decentralised to Toulouse...
identified a broad area of low pressure between 45°E
45th meridian east
The meridian 45° east of Greenwich is a line of longitude that extends from the North Pole across the Arctic Ocean, Europe, Asia, Africa, the Indian Ocean, the Southern Ocean, and Antarctica to the South Pole....
and 55°E
55th meridian east
The meridian 55° east of Greenwich is a line of longitude that extends from the North Pole across the Arctic Ocean, Europe, Asia, the Indian Ocean, the Southern Ocean, and Antarctica to the South Pole....
and from 8°S
8th parallel south
The 8th parallel south is a circle of latitude that is 8 degrees south of the Earth's equatorial plane. It crosses the Atlantic Ocean, Africa, the Indian Ocean, Southeast Asia, Australasia, the Pacific Ocean and South America....
to 15°S
15th parallel south
The 15th parallel south is a circle of latitude that is 15 degrees south of the Earth's equatorial plane. It crosses the Atlantic Ocean, Africa, the Indian Ocean, Australasia, the Pacific Ocean and South America....
. Within this area, two lows were detected. The main one (11R) was north of Mascarnes Islands while the other one was north of Madagascar.
11R became a tropical depression on March 3 and was later named Diwa. The name was contributed by Malawi. At first Diwa was classified as a moderate tropical storm by Mauritius, but as a tropical depression by Météo France, but a few hours later, Météo France also classified it as a tropical storm. This made the fourth documented case of a tropical cyclone being named before reaching tropical storm strength.
On the other hand, the other low briefly developed into a tropical disturbance (12R) on March 4. The two systems were less than 700 km away and Météo France said that Diwa might be partially influenced by a slight Fujiwhara effect
Fujiwhara effect
The Fujiwhara effect or Fujiwara interaction, named after Sakuhei Fujiwhara, is a type of interaction between two nearby cyclonic vortices, causing them to appear to "orbit" each other.-Description:...
with 12R. 12R was short-lived and Diwa remained the dominant system. Diwa came very near to Réunion
Réunion
Réunion is a French island with a population of about 800,000 located in the Indian Ocean, east of Madagascar, about south west of Mauritius, the nearest island.Administratively, Réunion is one of the overseas departments of France...
but never made landfall. The outer edges of Diwa did caused some substantial rainfall on the island. The strongest gust reported was 194 km/h at the top of the Sainte-Rose Large-Piton. The highest rainfall in three days was 2720 mm in Commerson. After this, Diwa moved southwards and strengthened into a severe tropical storm on March 7. Eventually, Diwa became extratropical and reached its peak intensity on March 9.
- Météo France's archive on the system, in FrenchFrench languageFrench is a Romance language spoken as a first language in France, the Romandy region in Switzerland, Wallonia and Brussels in Belgium, Monaco, the regions of Quebec and Acadia in Canada, and by various communities elsewhere. Second-language speakers of French are distributed throughout many parts...
. - Archive for Diwa from the Tropical Cyclone Center Database.
Tropical Disturbance 12R
Formed and dissipated on March 4, 2006.- Tropical Cyclone Database's storm summary and track file for 12R
Moderate Tropical Storm Elia
The unusually tenacious disturbance that would develop into Elia was first identified by NRL on April 2. It lingered around and organized very slowly. After waiting for nine days, it gathered gales in southern quadrants and Australian Bureau of Meteorology issued a shipping warning on April 11. It entered Météo France's area of responsibility as a Moderate Tropical Storm and was named Elia on April 13. The name was contributed by Madagascar. Elia encountered unfavourable shear conditions on April 15 causing the low level circulation to decouple from the convection. It degenerated into a remnant low the following day and finally dissipated on April 17.- Météo France's archive on the system, in FrenchFrench languageFrench is a Romance language spoken as a first language in France, the Romandy region in Switzerland, Wallonia and Brussels in Belgium, Monaco, the regions of Quebec and Acadia in Canada, and by various communities elsewhere. Second-language speakers of French are distributed throughout many parts...
.
Storm names
A tropical disturbance is named when it reaches moderate tropical storm strength. If a tropical disturbance reaches moderate tropical storm status west of 55°E55th meridian east
The meridian 55° east of Greenwich is a line of longitude that extends from the North Pole across the Arctic Ocean, Europe, Asia, the Indian Ocean, the Southern Ocean, and Antarctica to the South Pole....
, then the Sub-regional Tropical Cyclone Advisory Centre in Madagascar
Madagascar
The Republic of Madagascar is an island country located in the Indian Ocean off the southeastern coast of Africa...
assigns the appropriate name to the storm. If a tropical disturbance reaches moderate tropical storm status between 55°E
55th meridian east
The meridian 55° east of Greenwich is a line of longitude that extends from the North Pole across the Arctic Ocean, Europe, Asia, the Indian Ocean, the Southern Ocean, and Antarctica to the South Pole....
and 90°E
90th meridian east
The meridian 90° east of Greenwich is a line of longitude that extends from the North Pole across the Arctic Ocean, Asia, the Indian Ocean, the Southern Ocean, and Antarctica to the South Pole.The Ninety East Ridge is named after the meridian....
, then the Sub-regional Tropical Cyclone Advisory Centre in Mauritius
Mauritius
Mauritius , officially the Republic of Mauritius is an island nation off the southeast coast of the African continent in the southwest Indian Ocean, about east of Madagascar...
assigns the appropriate name to the storm. A new annual list is used every year so no names are retired.
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See also
- Tropical cyclone scalesTropical cyclone scalesTropical systems are officially ranked on one of several tropical cyclone scales according to their maximum sustained winds and in what oceanic basin they are located...
- List of Southern Hemisphere tropical cyclone seasons
- Atlantic hurricane seasons: 20052005 Atlantic hurricane seasonThe 2005 Atlantic hurricane season was the most active Atlantic hurricane season in recorded history, repeatedly shattering numerous records. The impact of the season was widespread and ruinous with an estimated 3,913 deaths and record damage of about $159.2 billion...
, 20062006 Atlantic hurricane seasonThe 2006 Atlantic hurricane season was significantly less active than the record previous season. It marked the first since 2001 in which no hurricanes made landfall in the United States, and was the first since 1994 that no tropical cyclones formed during October. Following the intense activity of... - Pacific hurricane seasons: 20052005 Pacific hurricane seasonThe 2005 Pacific hurricane season officially began on May 15, 2005 in the eastern Pacific and on June 1, 2005 in the central Pacific, and lasted until November 30, 2005. These dates conventionally delimit the period of each year when most tropical cyclones form in the northeastern Pacific Ocean...
, 20062006 Pacific hurricane seasonThe 2006 Pacific hurricane season was the most active Pacific hurricane season since 2000 producing 19 tropical storms or hurricanes. Eighteen developed within the National Hurricane Center area of warning responsibility, which is east of 140ºW, and one storm formed between 140ºW and the... - Pacific typhoon seasons: 20052005 Pacific typhoon seasonThe 2005 Pacific typhoon season had no official bounds; it ran year-round in 2005, but most tropical cyclones tend to form in the northwestern Pacific Ocean between May and November...
, 20062006 Pacific typhoon seasonThe 2006 Pacific typhoon season had no official bounds; it ran year-round in 2006, but most tropical cyclones tend to form in the northwestern Pacific Ocean between May and November... - North Indian Ocean cyclone seasons: 2005, 2006