Jump to content

Cyclone Dumazile

From Wikipedia, the free encyclopedia

This is an old revision of this page, as edited by Hurricane Noah (talk | contribs) at 21:39, 3 July 2021 (→‎Preparations, impact, and aftermath: fixes). The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.

Intense Tropical Cyclone Dumazile
Intense tropical cyclone (SWIO scale)
Category 3 tropical cyclone (SSHWS)
Dumazile at peak intensity east of Madagascar on 5 March 2018
Formed2 March 2018 (2 March 2018)
Dissipated10 March 2018 (10 March 2018)
(Post-tropical after 6 March)
Highest winds10-minute sustained: 165 km/h (105 mph)
1-minute sustained: 205 km/h (125 mph)
Gusts: 230 km/h (145 mph)
Lowest pressure945 hPa (mbar); 27.91 inHg
FatalitiesNone
Damage> $3.73 million (2018 USD)
Areas affectedMadagascar, Réunion
Part of the 2017–18 South-West Indian Ocean cyclone season

Intense Tropical Cyclone Dumazile was a strong tropical cyclone that brought flooding to the east coast of Madagascar and Réunion in early March 2018. Dumazile originated from an area of low pressure that formed near Agaléga on 27 February. The system concentrated into a tropical disturbance on 2 March and was named Dumazile the next day, as it intensified into a tropical storm. Amid favourable environmental conditions, Dumazile strengthened over the next two days and reached peak intensity on 5 March as an intense tropical cyclone, with 10-minute sustained winds of 165 km/h (105 mph), 1-minute sustained winds of 205 km/h (125 mph), and a central pressure of 945 hPa (27.91 inHg). The system weakened steadily over the next couple of days because of increasing wind shear as it tracked to the southeast. Dumazile became post-tropical on 7 March and eventually dissipated completely on 10 March near the Kerguelen Islands.

In Réunion, Dumazile came less than two months after Cyclone Berguitta dropped torrential rainfall over the island in mid-January. This meant ongoing repairs to bridges and reconstruction efforts after Berguitta were interrupted or set back, especially on the highway between Îlet Furçy and Cilaos. Floodwaters and landslides caused significant damage to the road network on Réunion, particularly in coastal and mountainous areas. Large waves along the coast caused erosion, leading to collapses of beachfront infrastructure and beach closures. Ports were also damaged by the waves, and in the case of Saint-Gilles, was clogged by debris. The agricultural sector incurred about €3 million (US$3.73 million) of damage, as crops were destroyed by floods and gusty winds. Fallen trees downed by strong winds blocked roads and damaged buildings. Recovery in Réunion was later hampered further by Cyclone Fakir in April. In Madagascar, rainfall warnings were issued for most of the east coast and some flooding occurred in Toamasina, as a result of malfunctioning drainage systems after Cyclone Ava in January.

Meteorological history

Map plotting the storm's track and intensity, according to the Saffir–Simpson scale
Map key
Saffir–Simpson scale
  Tropical depression (≤38 mph, ≤62 km/h)
  Tropical storm (39–73 mph, 63–118 km/h)
  Category 1 (74–95 mph, 119–153 km/h)
  Category 2 (96–110 mph, 154–177 km/h)
  Category 3 (111–129 mph, 178–208 km/h)
  Category 4 (130–156 mph, 209–251 km/h)
  Category 5 (≥157 mph, ≥252 km/h)
  Unknown
Storm type
triangle Extratropical cyclone, remnant low, tropical disturbance, or monsoon depression

A large region of unsettled weather along the Intertropical Convergence Zone spawned a broad area of low pressure in the vicinity of Agaléga on 27 February 2018.[1][2] The system became more concentrated and well-defined as it drifted between Agaléga and Tromelin Island,[3] leading Météo-France La Réunion (MFR) to classify it as a Zone of Disturbed Weather at 00:00 UTC on 1 March.[4][nb 1] That night, increased thunderstorm activity in conjunction with an easterly wind burst furthered development,[6] and the MFR reported that the system became Tropical Disturbance 06 at 06:00 UTC on 2 March;[4] at the same time, the Joint Typhoon Warning Center (JTWC) classified the system as a tropical depression.[7][nb 2] The incipient disturbance underwent a small clockwise loop over the rest of 2 March, amid opposing steering flows from the north and south.[9] During that time, the disturbance improved in organisation, with the development of a curved rainband. The MFR noted the surrounding atmospheric environment to be quite conducive to strengthening, with low wind shear, high relative humidity values, and pronounced outflow channels.[10] The JTWC stated that the system had become a tropical storm at 12:00 UTC on 2 March, as it began producing 1-minute sustained winds of 65 km/h (40 mph).[7] The MFR also upgraded the system to a tropical storm at 00:00 UTC on 3 March, based on scatterometer data, upon which it received the name Dumazile.[11]

Modest strengthening ensued on 3 March as Dumazile began to move southwestward, in response to a developing ridge to its east. A pocket of dry air to Dumazile's west caused the cyclone's low-level circulation center to briefly become exposed, before it was quickly obscured by new bursts of thunderstorms.[12] Faster intensification began on 4 March, as the inner core began to tighten up and the radius of maximum wind decreased,[13] with the MFR upgrading Dumazile to a severe tropical storm by 06:00 UTC.[4] Microwave satellite imagery displayed a nascent eyewall on the evening of 4 March,[14] leading the MFR to assess that Dumazile had reached tropical cyclone strength by 18:00 UTC.[4] An eye became increasingly apparent as Dumazile turned south-southeastward, while rounding the periphery of the ridge to its east, coinciding with significant strengthening through the morning of 5 March.[15][16] By 12:00 UTC, Dumazile reached its peak intensity as an intense tropical cyclone, with 10-minute sustained winds of 165 km/h (105 mph), gusts up to 230 km/h (145 mph), and a minimum pressure of 945 hPa (27.91 inHg), as estimated by the MFR;[4] the JTWC concurrently estimated 1-minute sustained winds to have reached 205 km/h (125 mph).[7] Despite the cyclone intensity, its eye remained somewhat oval in shape, likely due to interaction of the northwestern part of the circulation with the mountainous terrain of Madagascar.[16]

Dumazile's peak was short-lived, as weakening began almost immediately, with an increase in northwesterly wind shear over the system associated with an upper-level trough.[17] The eye collapsed entirely on 6 March as Dumazile began interacting with the upper-level trough,[18] and the system fell back to severe tropical storm status by 18:00 UTC.[4] Thunderstorm activity quickly became confined to Dumazile's southeastern quadrant as a result of dry air and shear,[19] leading the MFR to declare Dumazile became post-tropical by 00:00 UTC on 7 March.[4] The JTWC, however, classified Dumazile as a subtropical storm at 12:00 UTC.[7] Extratropical transition began later on 7 March, while Dumazile accelerated southeastward into the midlatitude westerlies.[20] The JTWC ceased tracking Dumazile at 18:00 UTC on 8 March,[7] while the MFR continued to monitor Dumazile as it became fully extratropical at 06:00 UTC on 9 March. The remnant system was last noted by the MFR just north of the Kerguelen Islands a day later.[4]

Preparations, impact, and aftermath

A cyclone pre-warning was issued for the island of Réunion on 4 March.[21] The cyclone pre-warning was ended at 6:00 p.m. Réunion Time on 5 March, as Dumazile veered away from the island. Schools, businesses, and daycare facilities remained closed through 6 March.[22][23][24] All schools reopened on 7 March, with the exception of several in Saint-Paul and Saint-Leu, where roadways were still blocked.[25] Torrential rainfall affected the island, with a 24-hour total of 990 mm (39 in) occurring at Grand Îlet. The Volcanic Highway, La Plaine-des-Palmistes, and Cilaos all experienced significant rainfall during the same period. The Saint-Gilles port had to be unblocked after the storm, due to debris and damage left behind.[21][26] The Sainte Suzanne river spilled its banks. Floodwaters cut off access to Saint-Denis from all but one road. The coastal and mountain highways were closed;[24] a section of the latter road was covered in debris after a landslide occurred.[21] Strong waves submerged four lanes of the coastal highway with seawater, and 150 mm (5.9 in) of rain fell on a cliff overlooking the road.[27] Numerous bridges were either swept away or submerged by floodwaters, and several roads were flooded across Cilaos and Salazie.[28] The RN5 highway was impassable for months at Îlet Furçy, after several landslides occurred during cyclones Ava, Berguitta, and Dumazile. Work to rebuild two bridges damaged during the storm, a project costing around €100 million (US$121.1 million), was halted after a prosecutor threatened criminal charges against officials for violating laws prohibiting circulating machinery from being in the Saint-Etienne river. Around 1,500 people protested the halt of the construction project.[29][30]

High waves along the shore decimated boats in the port of Sainte-Marie. The Roches Noires beach was completely submerged in water.[21] A fence and the northern access to an esplanade at the beach collapsed.[31] Significant portions of sand were washed away from the beach, exposing the foundations of the esplanade.[32] The MNS station and three masts used for signalling sustained damage. As a result, the lifeguard station was closed and rescues were no longer possible.[33][34] Authorities in Saint-Paul municipality worked to create a barrier made of boulders,[31] repair an observation deck, and repair ramps leading to the beach. The project was estimated to cost about €46,000 (US$56,000).[32] Access to the beach was prohibited from 19 March–6 April, as a precautionary measure to prevent injuries.[35] Tarpaulins covering crops on the Cisaille Plateau were ripped off. All of the crops near Salazie were destroyed after 1,600 mm (63 in) of rain fell.[36] New crops planted after Cyclone Berguitta were destroyed, leading to shortages of fruits and vegetables.[37] Repair work on the Cilaos bridge was halted, due to severe conditions during the storm. Residents erected a temporary bridge using ladders, in order to rescue 400 marooned people elsewhere in Cilaos and another 100 on a beach near Îlet Furçy.[38] Landslides occurred in two neighborhoods of Brittany, and a wall collapsed in the mountainous region. Trees fell at two nursery schools in Saint-Denis.[39] Severe damage was inflicted to the road system on Réunion. Roads across the island experienced landslides, flooding, and downed trees.[40]

A large lake developed on the Plaine des Cafres, due to heavy rainfall. East and westbound traffic, traveling across the island, was restricted to the Plaines highway due to other roads flooding.[41] A landslide in the Piton Cailloux District, Sainte-Marie, isolated around 10 families.[42] A trail from Bois Court and Grand Bassin was closed, due to damage sustained during cyclones Berguitta and Dumazile. Cliff repair work was scheduled for March, with a planned reopening date in April.[43] A water boil advisory was issued for Saint-Joseph. Portions of Salazie were left without potable water. In the municipality of Saint Benoit, water dearths and even a lack of potable water were expected by authorities.[44] Low-lying areas in the Chaudron neighborhood, Sainte-Clotilde, flooded during the storm. Authorities worked to clear out drainage systems.[45] The Dos d'Ane–Deux Bras hiking trail reopened on 17 July, after suffering damage during cyclones Berguitta, Dumazile, and Fakir.[46] Temporary barriers in Tampon were stolen during the storm; the barriers were found in a ditch.[47] Agricultural damage on Réunion was €3 million (US$3.73 million).[48] Approximately €2.3 million (US$2.8 million) in aid was released to farmers who suffered losses during cyclones Berguitta, Dumazile, and Fakir.[49]

Due to the threat of severe weather in Madagascar, a yellow alert was issued for the regions of Analanjirofo, Atsinanana, Diana, Sava, and Sofia, as well as the Farafangana, Nosy Varika, Manakara, Mananjary, and Vohipeno districts. Portions of Toamasina flooded during the storm, as a result of malfunctioning drainage systems that were damaged during Cyclone Ava.[50]

See also

Notes

  1. ^ Météo-France La Réunion is the Regional Specialised Meteorological Centre for the South-West Indian Ocean[5]
  2. ^ While not designated by the World Meteorological Organization as a Regional Specialised Meteorological Centre, the JTWC issues warnings on tropical cyclones in all of the major tropical cyclone basins to supplement the activities of United States government agencies.[8]

References

  1. ^ "Bulletin for Cyclonic Activity and Significant Tropical Weather in the Southwest Indian Ocean 2018/02/26 at 1200 UTC" (PDF). Météo-France La Réunion. 26 February 2018. Retrieved 26 June 2021.
  2. ^ "Bulletin for Cyclonic Activity and Significant Tropical Weather in the Southwest Indian Ocean 2018/02/27 at 1200 UTC" (PDF). Météo-France La Réunion. 27 February 2018. Retrieved 26 June 2021.
  3. ^ "Bulletin for Cyclonic Activity and Significant Tropical Weather in the Southwest Indian Ocean 2018/03/01 at 1200 UTC" (PDF). Météo-France La Réunion. 1 March 2018. Retrieved 26 June 2021.
  4. ^ a b c d e f g h "Dumazile: 2018-03-01 to 2018-03-10". Météo-France La Réunion. Retrieved 26 June 2021.
  5. ^ "Qu'est-ce qu'un CMRS/cyclones tropicaux?" (in French). Météo-France La Réunion. Retrieved 2 June 2021.
  6. ^ "Tropical Cyclone Forecast Warning (South-West Indian Ocean) Warning Number 1/6/20172018 Tropical Disturbance 6" (PDF). Météo-France La Réunion. 2 March 2021. Retrieved 26 June 2021.
  7. ^ a b c d e "2018 Intense Tropical Cyclone DUMAZILE (2018060S13057)". The International Best Track Archive for Climate Stewardship. University of North Carolina Asheville. Retrieved 26 June 2021.
  8. ^ "Products and Services Notice". Joint Typhoon Warning Center. Retrieved 7 June 2021.
  9. ^ "Tropical Cyclone Forecast Warning (South-West Indian Ocean) Warning Number 2/6/20172018 Tropical Disturbance 6" (PDF). Météo-France La Réunion. 2 March 2021. Retrieved 26 June 2021.
  10. ^ "Tropical Cyclone Forecast Warning (South-West Indian Ocean) Warning Number 3/6/20172018 Tropical Depression 6" (PDF). Météo-France La Réunion. 2 March 2021. Retrieved 26 June 2021.
  11. ^ "Tropical Cyclone Forecast Warning (South-West Indian Ocean) Warning Number 4/6/20172018 Moderate Tropical Storm 6 (Dumazile)" (PDF). Météo-France La Réunion. 3 March 2021. Retrieved 26 June 2021.
  12. ^ "Tropical Cyclone Forecast Warning (South-West Indian Ocean) Warning Number 6/6/20172018 Moderate Tropical Storm 6 (Dumazile)" (PDF). Météo-France La Réunion. 3 March 2021. Retrieved 26 June 2021.
  13. ^ "Tropical Cyclone Forecast Warning (South-West Indian Ocean) Warning Number 9/6/20172018 Severe Tropical Storm 6 (Dumazile)" (PDF). Météo-France La Réunion. 4 March 2021. Retrieved 26 June 2021.
  14. ^ "Tropical Cyclone Forecast Warning (South-West Indian Ocean) Warning Number 11/6/20172018 Tropical Cyclone 6 (Dumazile)" (PDF). Météo-France La Réunion. 4 March 2021. Retrieved 26 June 2021.
  15. ^ "Tropical Cyclone Forecast Warning (South-West Indian Ocean) Warning Number 12/6/20172018 Tropical Cyclone 6 (Dumazile)" (PDF). Météo-France La Réunion. 5 March 2021. Retrieved 26 June 2021.
  16. ^ a b "Tropical Cyclone Forecast Warning (South-West Indian Ocean) Warning Number 13/6/20172018 Tropical Cyclone 6 (Dumazile)" (PDF). Météo-France La Réunion. 5 March 2021. Retrieved 26 June 2021.
  17. ^ "Tropical Cyclone Forecast Warning (South-West Indian Ocean) Warning Number 15/6/20172018 Tropical Cyclone 6 (Dumazile)" (PDF). Météo-France La Réunion. 5 March 2021. Retrieved 26 June 2021.
  18. ^ "Tropical Cyclone Forecast Warning (South-West Indian Ocean) Warning Number 17/6/20172018 Tropical Cyclone 6 (Dumazile)" (PDF). Météo-France La Réunion. 6 March 2021. Retrieved 26 June 2021.
  19. ^ "Tropical Cyclone Forecast Warning (South-West Indian Ocean) Warning Number 20/6/20172018 Post-Tropical Depression 6 (Ex-Dumazile)" (PDF). Météo-France La Réunion. 7 March 2021. Retrieved 26 June 2021.
  20. ^ "Tropical Cyclone Forecast Warning (South-West Indian Ocean) Warning Number 23/6/20172018 Post-Tropical Depression 6 (Ex-Dumazile)" (PDF). Météo-France La Réunion. 7 March 2021. Retrieved 26 June 2021.
  21. ^ a b c d "Dumazile tire sa révérence...et laisse des traces". Imaz Press (in French). 7 March 2018. Archived from the original on 4 June 2021. Retrieved 8 June 2021.
  22. ^ "Dumazile : La préfecture lève la pré-alerte cyclonique, les établissements scolaires restent fermés". Zinfos 974 (in French). 5 March 2018. Archived from the original on 4 June 2021. Retrieved 6 June 2021.
  23. ^ Touzé, Lucie (6 March 2018). "Cyclone Dumazile : le préfet fait le point, tous les établissements scolaires fermés demain". Linfo.re (in French). Archived from the original on 4 June 2021. Retrieved 6 June 2021.
  24. ^ a b Borella, Jean-Clément (6 March 2018). "La Réunion encore frappée par des pluies torrentielles". Le Parisien (in French). Archived from the original on 4 June 2021. Retrieved 10 June 2021.
  25. ^ Touzé, Lucie (7 March 2018). "Transports scolaires : perturbations dans plusieurs secteurs de St-Paul et St-Leu". Linfo.re (in French). Archived from the original on 5 June 2021. Retrieved 10 June 2021.
  26. ^ "Dumazile laisse beaucoup d'eau dans son sillage". Imaz Press Réunion (in French). 6 March 2018. Archived from the original on 4 June 2021. Retrieved 6 June 2021.
  27. ^ "L'île toujours coupée en deux". Clicanoo (in French). 6 March 2018. Archived from the original on 4 June 2021. Retrieved 11 June 2021.
  28. ^ "Fragile réseau routier, trois jours de mauvais temps, que d'eau, que d'eau, expression, météo". Imaz Press (in French). 7 March 2018. Archived from the original on 5 June 2021. Retrieved 12 June 2021.
  29. ^ Dupuy, Pierrot (8 March 2018). "Route de Cilaos : Quand la préfecture et le procureur jouent les faux cul". Zinfos 974 (in French). Archived from the original on 4 June 2021. Retrieved 12 June 2021.
  30. ^ Patel, Yacoub (8 March 2018). "'Nous, yabs, ne sommes pas moins que des poissons'". Clicanoo (in French). Archived from the original on 4 June 2021. Retrieved 12 June 2021.
  31. ^ a b Touzé, Lucie (13 March 2018). "La plage des Roches Noires méconnaissable, des travaux annoncés". Linfo.re (in French). Archived from the original on 4 June 2021. Retrieved 9 June 2021.
  32. ^ a b Boyer, Annabelle (4 April 2018). "Plage des Roches Noires : début des travaux de protection" (in French). France TV Info. Archived from the original on 4 June 2021. Retrieved 10 June 2021.
  33. ^ "La plage des Roches Noires ne peut plus être surveillée". Zinfos 974 (in French). 8 March 2018. Archived from the original on 4 June 2021. Retrieved 11 June 2021.
  34. ^ "Roches-Noires: La baignade et les activités nautiques ne sont plus surveillées jusqu'à nouvel ordre". Clicanoo (in French). 8 March 2018. Archived from the original on 4 June 2021. Retrieved 11 June 2021.
  35. ^ Boyer, Annabelle (20 March 2018). "La plage des Roches Noires interdite d'accès jusqu'au 6 avril" (in French). France TV Information. Archived from the original on 4 June 2021. Retrieved 11 June 2021.
  36. ^ Touzé, Lucie (7 March 2018). "Salazie : le désespoir des agriculteurs sinistrés". Linfo.re (in French). Archived from the original on 4 June 2021. Retrieved 8 June 2021.
  37. ^ Valmont, Sébastien (10 March 2018). "Les fruits et légumes péi bientôt en rupture de stock". Clicanoo (in French). Archived from the original on 4 June 2021. Retrieved 11 June 2021.
  38. ^ "Route de Cilaos : les habitants créent un pont de fortune". Linfo.re (in French). 7 March 2018. Archived from the original on 4 June 2021. Retrieved 9 June 2021.
  39. ^ Touzé, Lucie (5 March 2018). "Dumazile : éboulis, inondations et arbres couchés à Saint-Denis". Linfo.re (in French). Archived from the original on 4 June 2021. Retrieved 12 June 2021.
  40. ^ Hoair, Gilbert (5 March 2018). "Dumazile : un point sur le réseau routier ce lundi soir" (in French). France TV Information. Archived from the original on 4 June 2021. Retrieved 12 June 2021.
  41. ^ Magnien, Marine (6 March 2018). "Il se baigne dans le lac éphémère de la Plaine des Cafres". Linfo.re (in French). Archived from the original on 5 June 2021. Retrieved 10 June 2021.
  42. ^ Touzé, Lucie (7 March 2018). "Ste-Marie: the anger of the inhabitants of Piton Cailloux following a landslide". Linfo.re (in French). Archived from the original on 11 June 2021. Retrieved 10 June 2021.
  43. ^ Touzé, Lucie (9 March 2018). "Réouverture partielle du sentier de Grand Bassin à Bois Court début avril". Linfo.re (in French). Archived from the original on 4 June 2021. Retrieved 10 June 2021.
  44. ^ "Coupures et eau dégradée sur plusieurs communes". Imaz Press (in French). 6 March 2018. Archived from the original on 4 June 2021. Retrieved 10 June 2021.
  45. ^ "Dumazile: Dégâts recensés sur le chef-lieu et mesures prises par la ville". Zinfos 974 (in French). 5 March 2018. Archived from the original on 4 June 2021. Retrieved 10 June 2021.
  46. ^ "Réouverture de deux sentiers à Mafate". Imaz Press (in French). 17 July 2018. Archived from the original on 4 June 2021. Retrieved 11 June 2021.
  47. ^ Labrousse, Regis (9 March 2018). "[Vidéo] Le Tampon: A-t-il retrouvé les barrières volées pendant Dumazile?". Zinfos 974 (in French). Archived from the original on 4 June 2021. Retrieved 11 June 2021.
  48. ^ @Clicanoore (12 March 2018). "#Dumazile : les pertes chiffrées à 3 millions d'euros" (Tweet). Retrieved 3 July 2021 – via Twitter.
  49. ^ Magnien, Marine (2 May 2018). "Le Département débloque 2,3 millions d'euros pour les agriculteurs". Linfo.re (in French). Archived from the original on 5 June 2021. Retrieved 11 June 2021.
  50. ^ Rahaga, Ny Aina (5 March 2018). "Toamasina de nouveau inondé suite aux intempéries". Madagascar Tribune (in French). Archived from the original on 4 June 2021. Retrieved 8 June 2021.
Wikimedia Commons has media related to Cyclone Dumazile.
Retrieved from "https://en.wikipedia.org/w/index.php?title=Cyclone_Dumazile&oldid=1031824453"