1992–93 South-West Indian Ocean cyclone season
The 1992–93 South-West Indian Ocean cyclone season lasted longer than normal, with the first storm Aviona forming on September 27 and the final storm Konita not dissipating until May 7. It was an above-average season, with four tropical cyclones - the equivalent of a minimal hurricane - along with six tropical storms, one subtropical depression, and several depressions including one that was named. The basin is defined as the area west of 90°E and south of the Equator in the Indian Ocean, which includes the waters around Madagascar westward to the east coast of Africa. Tropical cyclones in this basin are monitored by the Regional Specialised Meteorological Centre in Réunion, as well as by the Joint Typhoon Warning Center.
At the time, the season officially went from November 15, 1991, to April 30, 1992, although this season began in September with the formation of Tropical Storm Aviona in the northeastern portion of the basin. A month later, Tropical Storm Babie also formed in the northeastern portion of the basin before the season's official start. After several depressions formed in December and early January, Cyclone Colina formed and struck Réunion, which damaged houses and killed 2 people and left 12 missing there. Three storms were active at the same time in the middle of January, including Colina - Tropical Storm Dessilia moved across Madagascar with gusty winds, and Cyclone Edwina was the longest-lasting and strongest storm of the season. Edwina brushed the Mascarene Islands with gusty winds and light rainfall. In mid-February, Tropical Storm Finella brought locally heavy rainfall to Réunion, reaching along the island's east coast and causing minimal rainfall along the southern coast. The Intertropical Convergence Zone became active toward the end of February, spawning tropical storms Gracia and Ionia as well as Tropical Depression Hutelle. Ionia, the last of five system to cross Madagascar during the season, killed eight people in the country. The season ended with Cyclone Jourdanne, which was the second-strongest storm of the season in April, and Cyclone Konita in May.
Seasonal summary
ImageSize = width:800 height:200
PlotArea = top:10 bottom:80 right:20 left:20
Legend = columns:3 left:30 top:58 columnwidth:270
AlignBars = early
DateFormat = dd/mm/yyyy
Period = from:01/09/1992 till:01/06/1993
TimeAxis = orientation:horizontal
ScaleMinor = grid:black unit:month increment:1 start:01/10/1992
Colors =
id:canvas value:gray
id:GP value:red
id:TD value:rgb legend:Tropical_Depression
id:TS value:rgb legend:Moderate_Tropical_Storm
id:ST value:rgb legend:Severe_Tropical_Storm
id:TC value:rgb legend:Tropical_Cyclone
id:IT value:rgb legend:Intense_Tropical_Cyclone
id:VI value:rgb legend:Very_Intense_Tropical_Cyclone
Backgroundcolors = canvas:canvas
BarData =
barset:Hurricane
bar:Month
PlotData=
barset:Hurricane width:11 align:left fontsize:S shift: anchor:till
from:27/09/1992 till:05/10/1992 color:TS text:"Aviona "
from:18/10/1992 till:21/10/1992 color:TS text:"Babie "
from:04/12/1992 till:10/12/1992 color:TD text:"C1 "
from:26/12/1992 till:30/12/1992 color:TD text:"C3 "
from:13/01/1993 till:20/01/1993 color:TC text:"Colina "
from:16/01/1993 till:24/01/1993 color:ST text:"Dessilia "
from:19/01/1993 till:29/01/1993 color:IT text:"Edwina "
barset:break
from:13/02/1993 till:15/02/1993 color:TS text:"Finella "
from:20/02/1993 till:23/02/1993 color:TS text:"Gracia "
from:26/02/1993 till:28/02/1993 color:TD text:"H1 "
from:27/02/1993 till:02/03/1993 color:TD text:"Hutelle "
from:02/03/1993 till:09/03/1993 color:TS text:"Ionia "
from:02/04/1993 till:10/04/1993 color:IT text:"Jourdanne "
from:02/05/1993 till:07/05/1993 color:TC text:"Konita "
bar:Month width:5 align:center fontsize:S shift: anchor:middle color:canvas
from:01/09/1992 till:01/10/1992 text:September
from:01/10/1992 till:01/11/1992 text:October
from:01/11/1992 till:01/12/1992 text:November
from:01/12/1992 till:01/01/1993 text:December
from:01/01/1993 till:01/02/1993 text:January
from:01/02/1993 till:01/03/1993 text:February
from:01/03/1993 till:01/04/1993 text:March
from:01/04/1993 till:01/05/1993 text:April
from:01/05/1993 till:01/06/1993 text:May
TextData =
pos:
text:""
During the season, the Météo-France office on Réunion island issued warnings in tropical cyclones within the basin. The agency estimated intensity through the Dvorak technique, and warned on tropical cyclones in the region from the coast of Africa to 90° E, south of the equator. The Joint Typhoon Warning Center, which is a joint United States Navy – United States Air Force task force, also issued tropical cyclone warnings for the southwestern Indian Ocean. The storms in the season lasted about five days on average, although Cyclone Edwina lasted the longest at 11 days. Storms formed throughout the basin and were fairly evenly distributed throughout the season, with the exception of a lull in November. Most storms originated from the Intertropical Convergence Zone. MFR named storms throughout the season using 11 names from a sequential list. The remainder of the list was Laura, Monette, Neige, Octavie, Pamela, Rosita, Stella, Tasiana, Vigonia, Wendy, and Yolande.
Systems
Moderate Tropical Storm Aviona
On September 25, a low pressure area persisted between the Cocos Islands and Sumatra in the Australian region, east of 90° E. It moved southwestward into the south-west Indian Ocean due to a large ridge to the south. The system slowly organized, becoming a tropical disturbance on September 27; on the same day, the JTWC also initiated advisories on the system as Tropical Cyclone 01S. This marked an unusual event of such an early storm formation. On September 29, the system was named Moderate Tropical Storm Aviona, although the MFR later assessed that the system reached tropical storm status on the previous day. In addition, the JTWC estimated the system attained 1-minute sustained peak winds of 120 km/h on September 28, the equivalent of a minimal hurricane. When Aviona was named, the MFR estimated peak 10-minute sustained winds of 75 km/h. Subsequently, increased wind shear incurred weakening due to a trough to the south, which stripped the convection from the center. A building ridge behind the trough turned Aviona to the west. The storm weakened to a depression on October 1, the same day the JTWC discontinued advisories. The circulation continued generally west-southwestward until dissipating on October 5 to the north of Rodrigues island.Moderate Tropical Storm Babie
The ITCZ became active on October 17, spawning an area of disturbed weather about east of Diego Garcia in conjunction with a pre-existing low pressure area. Convection quickly organized around a center, and a tropical disturbance formed on October 18. On the same day, the JTWC began issuing warnings on the system as Tropical Cyclone 02S. A trough to the south steered the system to the south-southwest. Following steady intensification, the disturbance became Tropical Storm Babie on October 19, reaching peak winds of 70 km/h. A building ridge to the south increased wind shear, causing Babie to quickly weaken; the JTWC and MFR discontinued advisories on October 21, and the circulation dissipated on October 23.Tropical Cyclone Colina
The ITCZ spawned an area of convection on January 11 near the Chagos Archipelago. A circulation developed within the system on January 13 about southwest of Diego Garcia, and at that time it became a tropical disturbance. A large ridge to the south steered the system generally to the southwest. The disturbance intensified into a depression on January 14, the same date that the JTWC initiated advisories on Tropical Cyclone 10S, and following an increase in convection, the depression intensified into Moderate Tropical Storm Colina on January 15. Turning more to the south-southwest, Colina strengthened further into a tropical cyclone on January 18, developing a eye. On the next day, the cyclone attained peak 10-minute winds of 135 km/h, according to MFR, while the JTWC estimated peak 1-minute winds of 175 km/h. That day, the eye crossed over the western portion of Réunion at around 14:30 UTC, exiting 45 minutes later. Subsequently, Colina accelerated to the southeast over cooler waters, weakening in the process. On December 20, the cyclone weakened to tropical storm status, and the next day Colina became extratropical, dissipating two days later.Early in its duration, Colina dropped rainfall in Seychelles through the interaction with the ITCZ. The rains caused flooding and mudslides, and the storm also produced high waves and gusty winds. Moving across Réunion, Colina produced strong wind gusts in the mountainous peaks, reaching at La Plaine-des-Palmistes. The storm dropped rainfall across the entire island, peaking at at Mafate in a 24‑hour period. The winds and rainfall damaged crops and houses and also caused power outages. The storm killed two people on the island during its passage, with 12 others missing. On nearby Mauritius, Colina dropped about of rainfall and produced wind gusts of ; the storm did not cause much damage there.
Severe Tropical Storm Dessilia
While Colina was intensifying northeast of Réunion, the monsoon spawned an area of convection in conjunction with a low pressure area in the Mozambique Channel. On January 16, the system developed into a tropical disturbance, although initially the circulation was poorly-defined. It moved toward the coast of Mozambique before turning southeastward and organizing more. The system intensified into Tropical Storm Dessilia on January 19, reaching peak 10 minute winds of 95 km/h at 12:00 UTC on the next day. At around that time, Dessilia made landfall on northwestern Madagascar between Morondava and Morombe. Over a 30-hour period, the storm moved southeastward across the country, remaining fairly well-organized. Initially, it appeared that Colina absorbed Dessilia once the latter storm emerged from the Madagascar coastline, although they remained separate systems. After having weakened to tropical depression status, Dessilia restrengthened into a tropical storm on January 22. Increased wind shear weakened the convection, and the storm dissipated on January 24; the next day, the remnants were absorbed by a passing cold front.While intensifying and passing near Juan de Nova Island, Dessilia produced wind gusts of. Wind gusts on Madagascar reached at Morombe. Later, the storm produced waves to the southwest coast of Réunion.
Intense Tropical Cyclone Edwina
A few days after Colina formed, the ITCZ spawned another area of convection on January 16 in the northeast portion of the basin. The next day, a low pressure area formed between the Chagos Archipelago and Diego Garcia, and on January 19 the system developed into a tropical disturbance after convection increased. Following further organization, the system intensified into Tropical Storm Edwina on January 20 while moving generally westward. Increasing wind shear prevented significant strengthening initially, but Edwina was able to intensify more on January 21. On January 23, the JTWC upgraded the storm to the equivalent of a minimal hurricane on the same day that MFR upgraded Edwina to tropical cyclone status. On the next day, the JTWC estimated the cyclone attained peak winds of 205 km/h, after Edwina developed a well-defined wide eye. On January 26, the MFR estimated that the cyclone reached peak 10-minute winds of 170 km/h, making Edwina the strongest storm of the season. Around that time, the cyclone turned more to the south around a large ridge, maintaining peak winds through January 27. By that time, the eye became large and ragged while passing halfway between Rodrigues and St. Brandon. On January 27, Edwina passed about east of Mauritius. On the next day, increased wind shear caused marked weakening, quickly destroying the eye and lowering the winds below tropical cyclone force. On January 29, Edwina ceased existing as a tropical system, although its remnants persisted several more days, affecting Île Amsterdam in the south-central Indian Ocean on February 2.On Rodrigues island, Edwina produced peak wind gusts of. The fringes of the storm affected Mauritius, producing peak gusts of and of rainfall. Farther west, Edwina produced gusts of on Réunion.
Moderate Tropical Storm Finella
A large low pressure area persisted on February 11 across northern Madagascar, centered near Cape Masoala along the country's eastern coast. Moving southward and later southeastward due to a trough, the system developed into a tropical disturbance on February 12 and slowly organized. On the next day, the JTWC began tracking the system as Tropical Cyclone 19S. The MFR upgraded the system to Tropical Storm Finella on February 14 after an eye feature developed within the central dense overcast. As a result, the JTWC upgraded the system to the equivalent of a minimal hurricane that day, estimating peak 1-minute winds of 130 km/h, although the MFR only estimated peak 10-minute winds of 80 km/h. Increased wind shear weakened Finella, and it was no longer a tropical depression on February 15.Finella produced localized heavy rainfall in Réunion. Saint-Benoît along the east coast recorded of precipitation in 24 hours, including that fell in just one hour. The southern portion of the island received minimal rainfall, in contrast.
Moderate Tropical Storm Gracia
A circulation within the ITCZ developed on February 20 just south of Mayotte in the Mozambique Channel. It developed good outflow and showed initial signs of development, although on February 21 the system weakened. The convection reorganized, developing a ragged eye with circular rainbands, and the system intensified into Tropical Storm Gracia on February 22. It was a small system, just 100 km from the Madagascar coast when it attained tropical storm status. Late on February 22, the storm attained peak winds of 70 km/h. Shortly thereafter, the convection rapidly disintegrated as Gracia made landfall on northwestern Madagascar near Besalampy, dissipating early on February 23. The storm produced locally heavy rainfall, reaching where it made landfall. The JTWC did not track the system.Moderate Tropical Storm Ionia
The ITCZ remained active in early March, spawning a tropical depression in the northern Mozambique Channel on March 2. It failed to organize at first, although an increase in convection on March 3 allowed the system to strengthen into Tropical Storm Ionia. That day, it attained peak winds of 65 km/h. After passing about 50 km north of Juan de Nova island, Ionia progressed southeastward and approached the western Madagascar coastline. The circulation paralleled the coast for about before moving ashore at Belo on March 4. The storm weakened over land, re-emerging over open waters on March 5 from southeastern Madagascar. Ionia briefly re-intensified into a tropical depression that night, but it lost tropical characteristics on March 7. The remnants persisted several more days until dissipating south of the Mascarene Islands on March 11.The fifth depression of the season to move across Madagascar, Ionia dropped heavy rainfall, reaching 356 mm in some areas; this caused river flooding in southern Madagascar. The storm left 3,644 people homeless and killed eight.
Intense Tropical Cyclone Jourdanne
After a period of inactivity lasting slightly less than a month, the tropics became active again in early April when the ITCZ spawned an area of convection in the northeastern portion of the basin. This was in association with a preexisting low pressure area, and developed into a tropical disturbance on April 2. On the next day, the JTWC began tracking the system as Tropical Cyclone 24S. The system moved to the west-southwest due to a ridge to the south, gradually intensifying due to favorable conditions, such as warm water temperatures. On April 4, the system intensified into a tropical storm and was given the name Jourdanne. An eye developed on April 5, indicating that the storm attained tropical cyclone status. Although the convection was initially elongated, Jourdanne became much more symmetrical on April 6, which corresponded to its peak 10-minute intensity of 165 km/h that day. Around the same time, the JTWC estimated peak 1-minute winds of 230 km/h, which was tied for the strongest system in the southern hemisphere in the cyclone year by the agency. Due to a trough in the region, Jourdanne executed a small loop and turned to a southeast drift. Gradually increasing wind shear induced weakening, causing the eye to dissipate on April 7. On the next day, Jourdanne weakened below tropical cyclone intensity, and on April 9, the convection was stripped from the center. By the next day, Jourdanne was no longer a tropical disturbance, although its remnants persisted April 15.Tropical Cyclone Konita
A low pressure area formed on April 29 to the southeast of the Chagos Archipelago with an area of convection, but it failed to organize into a tropical disturbance until May 2. By that time, the JTWC was already classifying it as Tropical Cyclone 26S, and the system gradually organized while moving southwestward. Despite being late in the season, the system intensified into Tropical Storm Konita on May 4, and the next day attained tropical cyclone status. The upgrade was based on satellite imagery showing an eye, with MFR estimating peak 10-minute winds of 130 km/h, and JTWC estimating 1-minute winds of 165 km/h. By the time of peak intensity, Konita was moving more to the south into an area of weak steering currents. A trough northwest of the storm caused the convection to rapidly diminish, leaving the center exposed from the thunderstorms on May 6. After moving erratically to the northeast and looping, Konita dissipated on May 7. The storm did not directly affect land, although it indirectly caused an increase of rainfall over Seychelles.Other systems
In addition to the 11 named storms, one of which failed to attain tropical storm status, there were several additional systems. The first was Tropical Depression C1, that originated from the ITCZ in the northeastern portion of the basin from a small area of convection on November 24. It moved westward with pulsating convection around the center, failing to organize due to the presence of wind shear. On December 4, the system organized into a tropical disturbance, and three days later it passed about north of the northern tip of Madagascar. That day, it intensified to tropical depression status, reaching peak winds of 50 km/h. Increased wind shear weakened the convection, and the circulation dissipated on December 10. On December 18, a tropical low developed in the Australian basin northeast of the Cocos Islands. It moved southwestward, intensifying into a tropical storm and being named Ken by the BoM. Wind shear in the region prevented much development, and the storm crossed into the south-west Indian Ocean on December 21. At that time, the MFR classified the system as Tropical Depression C2, but the agency only issued two warnings. The JTWC tracked the system until December 23 when the system dissipated well to the southwest of Indonesia.On December 24, a cold front exited the southern African coastline, accompanied by a low pressure area that moved into the Mozambique Channel. The system produced a large area of convection, and with warm water temperatures in the area, the low gradually organized. On December 26, the MFR began tracking the system off the southwest coast of Madagascar. Around that time, the convection began to wrap into the center, while the system produced gale-force winds on Europa Island. The storm tracked generally to the southeast, passing south of Madagascar while intensifying gradually. Due to the structure, the storm was considered a subtropical depression. Late on December 26, the storm attained peak winds of 65 km/h, but subsequently, increased wind shear caused weakening. The subtropical storm continued to the southeast until December 30, when an approaching trough absorbed it.
After the subtropical depression dissipated, there were three additional depressions before Tropical Cyclone Colina developed on January 11. The ITCZ became active toward the end of February. On February 24, Tropical Disturbance H1 formed from a low pressure area to the west of Réunion. It moved quickly to the southeast, intensifying into a tropical depression, but dissipating on February 26 when it was absorbed into a trough. A day later, another disturbance formed near Réunion, which produced torrential rainfall, reaching in some locations. The system moved westward, intensifying into a tropical depression after further organization. Despite not being a tropical storm, the system was named Hutelle by the Meteorological Service of Madagascar on March 1. Shortly thereafter, Hutelle made landfall near Mahanoro, Madagascar, and dissipated the next day.