The 2022-23 South-West Indian Ocean cyclone season was a slightly above-average season, featuring 10 named storms; of these, 5 intensified into tropical cyclones, with 2 furthermore becoming intense tropical cyclones. It opened with the formation of Tropical Cyclone Ashley on 27 November 2022 and ended with the dissipation of Moderate Tropical Storm Horacio on 4 April 2023. All of the storms in this season fell within the traditional boundaries for a South-West Indian Ocean season, specifically from 15 November to 30 April. Throughout the season, one storm crossed over into the Australian region basin, with two others crossing from the Australian region into the South-West Indian Ocean. Any tropical and subtropical cyclones that exist in this basin are monitored by the area’s Regional Specialised Meteorological Centre (RSMC), Météo-France La Réunion (MFR), along with the Joint Typhoon Warning Center (JTWC).
The designation of Tropical Depression 01 on 27 November marked the beginning of the season, with it eventually being named Ashley and becoming a category 1 tropical cyclone. Though it did not make landfall, its remnants impacted eastern Madagascar, causing a light-to-moderate rainfall event there. In late December, Intense Tropical Cyclone Cheneso became a category 4-equivalent storm on the Saffir-Simpson scale and caused considerable impacts across Rodrigues, though due to the island’s small size, Cheneso’s overall damage total was fairly minor in comparison. In mid-January came Severe Tropical Storm Dingani, which hugged the coast of Mozambique and ultimately made landfall near peak intensity. Though Cheneso and Dingani were two of the season’s most impactful storms, other systems tracked by MFR and/or the JTWC, namely Tropical Depression 07 and Zone of Disturbed Weather 10, caused local impacts in Madagascar. The 2022-23 season eventually concluded with Tropical Storm Horacio in late March and early April, which struck the east coast of Madagascar as a tropical storm but eventually veered out to sea when it reached its eventual peak intensity. Over time, it lost its tropical characteristics and was re-designated as an extratropical cyclone on the 4th. In all, the season causes $173.37 million (2023 USD) in damages and was responsible for 96 fatalities, most of which were associated with flooding caused by Dingani.
After the end of this season, the method for naming South-West Indian Ocean tropical cyclones was changed to use lists that rotate without regard for year, rather than beginning on a new list every season. In addition, instead of having each name only be used once, they will now be reused unless their associated storm caused significant damage or other impacts, in which case said name would be retired and replaced with a new one. This naming scheme change occurred to make it more consistent with those in other basins, while also providing a more predictable and efficient structure for naming storms.
Seasonal summary[]
The 2022-23 South-West Indian Ocean cyclone season was overall near average, featuring 14 designated disturbances, 13 depressions, 10 named storms, 5 tropical cyclones, and 2 intense tropical cyclones. It began on 27 November with the formation of Moderate Tropical Storm Ashley, which eventually reached tropical cyclone status per MFR’s analysis on the 29th. After having dissipated on the 1st of December, its remnants briefly impacted some of Madagascar, though they were overall negligible. On 7 December, the season’s second tropical depression formed, with it then becoming a moderate tropical storm and getting named Balita the following day. Four days later, Tropical Cyclone Ellie traversed into the South-West Indian Ocean as a severe tropical storm but soon began to weaken after doing so, lasting only one day after crossing over. The third named storm of the season, Cheneso, went on to become a category 4 tropical cyclone and caused significant impacts over Rodrigues. The first storm of January 2023, Tropical Depression 04, briefly lasted from the 4th to the 5th of the month, remaining out to sea. By the middle of the month, Severe Tropical Storm Dingani had formed, with it eventually striking near Quelimane, Mozambique around peak intensity. Dingani was the deadliest storm of the season, claiming 61 lives; however, the name was not retired. The last storm of the month, Enali, became a category 2-equivalent system for about half of a day before abruptly weakening and later becoming an extratropical cyclone.
The first half of February saw two short-lived tropical depressions, the first of which struck northern Madagascar shortly after forming. The second one stayed away from land and crossed over into the Australian region on the same day it had formed. On the 22nd, the somewhat slow-moving Moderate Tropical Storm Fabien was named and strengthened fairly quickly over the coming days. It ultimately intensified to become the most intense storm of the season, with a pressure of 928 hPa (27.40 inHg) and mean 10-minute winds of 215 km/h (130 mph). By the 27th, while the storm had been on a weakening trend, the Australian region’s Cyclone Anggrek had moved into the area. However, unfavorable environmental conditions caused it to deteriorate soon after. On 9 March, Zone of Disturbed Weather 10 was designated in the Mozambique Channel, and although it was noted as having a brief chance to organize further, these chances soon ended as it made landfall over southern Madagascar. The final hurricane-force system of the year, Gezani, lasted throughout the third week of March and peaked with 10-minute sustained winds of 140 km/h (85 mph). Moderate Tropical Storm Horacio was the last overall storm, with it making landfall over Madagascar and emerging into open waters afterwards. However, it briefly reformed and finally had lost its tropical cyclone status by 4 April, thus concluding the 2022-23 season.
Systems[]
Tropical Cyclone Ashley[]
| Tropical cyclone (MFR) | |
| Category 1 tropical cyclone (SSHWS) | |
  | |
| Duration | 27 November – 1 December |
|---|---|
| Peak intensity | 120 km/h (75 mph) (10-min) 976 hPa (mbar) |
On 25 November, a low-pressure area located north-northeast of Mauritius was noted by Météo-France La Réunion (MFR). The following day, they recognized it as a tropical disturbance, and the Joint Typhoon Warning Center (JTWC) issued a Tropical Cyclone Formation Alert (TCFA) for the system. It quickly consolidated due to high moisture and warm ocean temperatures, organizing into a tropical depression at 12:00 UTC on the 27th. The system started to intensify due to the continuously-favorable environment, with it strengthening into Moderate Tropical Storm Ashley the next morning; it maintained a robust intensification pace, attaining severe tropical storm strength 12 hours later. Ashley began to develop an eye feature surrounded by very cold cloud tops within the central dense overcast, and at 06:00 UTC on the 29th, it became a tropical cyclone on MFR's scale. Environmental conditions began to level off thereafter, causing it to halt its intensification trend; the storm's peak intensity ultimately consisted of 3-minute sustained winds clocking at 140 km/h (75 mph) and a minimum central pressure of 976 hPa (28.82 inHg). After tracking into cooler waters, a weakening trend began, with MFR downgrading it to severe tropical storm strength on the 30th. Remaining on a southwestward trajectory towards Madagascar, its structure continued to deteriorate as convection warmed and wind shear increased. Ashley's associated showers and thunderstorms began to move ashore over Madagascar late on the 30th, though the storm's status further fell to that of a tropical depression at 12:00 UTC on 1 December. Twelve hours later, just as the center made landfall, it was downgraded to a low pressure area as it no longer possessed any organized convection; the storm lingered along the coast for a day or so before recurving back out to sea.
Moderate Tropical Storm Balita[]
| Moderate tropical storm (MFR) | |
| Tropical storm (SSHWS) | |
  | |
| Duration | 7 December – 10 December |
|---|---|
| Peak intensity | 85 km/h (50 mph) (10-min) 992 hPa (mbar) |
A slow-moving zone of disturbed weather was monitored by MFR towards the eastern edge of the basin. The JTWC, also tracking it, designated it as Invest 95S. The disturbance began to curve southwards and showed signs of significant organization, prompting the JTWC to issue a TCFA on it on 6 December. Favorable environmental conditions allowed it to develop a well-defined circulation that led it to be classified as a tropical depression at 12:00 UTC on 7 December. After several more hours, it strengthened into a tropical storm according to the JTWC; additionally, MFR made a similar assessment that same day and named it Moderate Tropical Storm Balita. Further strengthening was gradual due to moderate wind shear, though it did manage to organize further over the following day. At 00:00 UTC on 9 December, Balita was estimated by MFR to have peaked with 10-minute sustained winds of 85 km/h (50 mph) and a pressure of 992 hPa (29.29 inHg). Thereafter, environmental conditions began to deteriorate, ceasing the storm's strengthening trend. It still maintained its intensity for approximately 12 hours, though afterwards, shear took a more significant toll on it and caused it to swiftly weaken. Early on the 10th, it fell to minimal tropical storm status and further became a tropical depression later that day. Ultimately, at 18:00 UTC, MFR stopped tracking the system, marking its transition into a remnant low; the JTWC did the same shortly afterwards.
Severe Tropical Storm Ellie[]
| Severe tropical storm (MFR) | |
| Category 1 tropical cyclone (SSHWS) | |
  | |
| Duration | 11 December (Entered basin) – 12 December |
|---|---|
| Peak intensity | 95 km/h (60 mph) (10-min) 981 hPa (mbar) |
Early on 11 December, the Australian region's Tropical Cyclone Ellie crossed over into the South-West Indian Ocean. With 10-minute sustained winds clocking at 95 km/h (60 mph) initially, MFR placed its status as a severe tropical storm, while the JTWC had its intensity estimate for the storm at minimal category 1 tropical cyclone status. However, Ellie had begun to weaken shortly before making the crossover to this basin, and as such, its wind speed began to decrease. The cyclone weakened to tropical storm-equivalent strength on the Saffir-Simpson scale a few hours after the crossover, and throughout the next day, shear and persistent dry air continued to contribute to the storm’s deterioration, with it becoming a depression at 12:00 UTC on 12 December. Another half-day afterwards, Ellie became a remnant low-pressure area and drifted westward. About a day afterwards, the same low was briefly marked by the JTWC as having a low chance of possible re-development into a tropical cyclone due to somewhat favorable conditions expected in its path, though ultimately such an event failed to materialize.
Intense Tropical Cyclone Cheneso[]
| Intense tropical cyclone (MFR) | |
| Category 4 tropical cyclone (SSHWS) | |
  | |
| Duration | 24 December – 30 December |
|---|---|
| Peak intensity | 205 km/h (125 mph) (10-min) 933 hPa (mbar) |
- Main article: Cyclone Cheneso (Zeta)
An area of low pressure formed over the open ocean several hundred miles north-northeast of Mauritius. Moving southward at a steady pace, MFR began to track it for possible development on 22 December. Due to the fact that the disturbance was located in a very moist environment with low wind shear, its convection strengthened and consolidated closer to the center; continuing to improve in its organization, it managed to attain tropical depression status at 00:00 UTC on 24 December. Later in the day, an ASCAT pass discovered gale-force winds occurring within the storm, prompting it to be upgraded to Moderate Tropical Storm Cheneso. Due to a brief dry air intrusion affecting the storm, its intensity stagnated somewhat and its thunderstorm activity became displaced; however, it shortly recovered and resumed intensification, attaining severe tropical storm intensity early on the 25th. Cheneso's forward speed began to decrease significantly, causing it to meander over an area of very high ocean heat content (OHC). As a result, its strengthening pace soon reached the threshold of rapid intensification; in just 24 hours, its 10-minute sustained winds increased from 110 km/h (70 mph) to 175 km/h (110 mph).
Over the next morning, Cheneso's wind speeds continued to increase, ultimately reaching category 4-equivalent status on the Saffir-Simpson scale. At 06:00 UTC on 28 December, it peaked with 10-minute winds clocking at 205 km/h (125 mph), along with a minimum central pressure of 933 hPa (27.55 inHg); on the MFR scale, it was ranked as an intense tropical cyclone. It possessed a pronounced eye with very intense convection within the eyewall, though significant upwelling from the storm prevented it from strengthening anymore. It started to pick up speed and entered a less favorable environment, which caused it to weaken to category 3-equivalent strength. Recurving to the southeast, Cheneso's eye swiftly filled in as ocean temperatures dropped off, and it soon showed signs of an extratropical transition shortly after falling to category 1 intensity. The storm completed its transition into a potent extratropical cyclone at 18:00 UTC on 30 December, prompting MFR to cease its advisories on the system; thereafter, it raced to the southeast while gradually leveling off in intensity.
As a major tropical cyclone, Cheneso narrowly missed landfall over Rodrigues, instead passing just to the west of it. However, the island still faced extremely strong winds from the storm's eyewall, leading to severe damage. In addition, Rodrigues remained in the storm's vicinity for over a day due to its slow forward speed, lengthening Cheneso's impact. Storm surge caused lots of flooding across the island, and 13 people perished as a result. The winds caused severe damage to numerous homes and uprooted many trees, in turn leading to downed power lines. Despite the island's small size, overall impacts accumulated to $2.9 million.
Tropical Depression 04[]
| Tropical depression (MFR) | |
  | |
| Duration | 4 January – 5 January |
|---|---|
| Peak intensity | 55 km/h (35 mph) (10-min) 1002 hPa (mbar) |
A broad area of convection formed over the northeastern portion of the basin on 01 January, as initially noted by MFR; shortly afterwards, the JTWC also began to track the disturbance, giving it a low chance of undergoing tropical cyclogenesis. The next day, it was classified as Zone of Disturbed Weather 04, and confidence began to increase in the storm's formation. Despite struggling to maintain its convective activity due to relatively cooler waters and some dry air, it still gradually showed some signs of organization; its low-level circulation visibly improved in definition over the course of the next few days, though its sparse convective cover prevented it from attaining tropical depression status at the time. However, after beginning to travel through a pool of warmer waters, its thunderstorm activity increased and consolidated closer to the center. MFR designated it as Tropical Depression 04 on 04 January, although the JTWC never declared it as one; the latter agency maintained that it only had a moderate chance of formation at the time. The depression began to weaken shortly after attaining tropical depression status due to entering cooler waters once more and experiencing moderate wind shear; the combination of the two prevented its convection from remaining organized, in turn leading much of it to be sheared away from the center. As this trend continued, it ultimately led to MFR issuing their final advisories on the storm a day later. The remnants of Tropical Depression 04 meandered westward for another day or so before dissipating sometime on the 6th.
Severe Tropical Storm Dingani[]
| Severe tropical storm (MFR) | |
| Tropical storm (SSHWS) | |
  | |
| Duration | 15 January – 18 January |
|---|---|
| Peak intensity | 95 km/h (60 mph) (10-min) 980 hPa (mbar) |
- Main article: Tropical Storm Dingani (Zeta)
A zone of disturbed weather exited the coast of northern Mozambique during the afternoon of January 13. After emerging into the Mozambique Channel, it executed a counter-clockwise loop while organizing over warm waters. The JTWC designated it a tropical depression early on the 15th, with MFR coming to a similar conclusion shortly thereafter. Both agencies upgraded it to a tropical storm at 12:00 UTC after an ASCAT pass indicated a swath of gale-force winds, thus meaning it was also assigned the name Dingani. The system curved to the west, back towards Mozambique, though it originally struggled to intensify due to moderate vertical wind shear. For the next day, satellite imagery showed gradual deterioration in the storm's structure as a result, though it maintained its status as a moderate tropical storm. However, after edging closer to land, it quickly encountered more favorable conditions and began to re-intensify. It quickly deepened and organized as its proximity to the coast increased; ultimately, it reached a peak intensity consisting of 95-km/h (60 mph) 10-minute sustained winds and a minimum central pressure of 980 hPa (28.94 inHg). Thereafter, Dingani leveled off in intensity somewhat before making landfall just north of Quelimane. Afterwards, land interaction induced quick weakening, with it falling to a tropical depression within just 6 hours. Another 12 hours later, Dingani degenerated into a remnant low, with MFR ceasing advisories on it as a result.
Since Dingani remained very close to Mozambique's coastline for the majority of its lifetime, it dropped high rain totals across the area. In the second half of its lifespan, its strong winds impacted the provinces of Sofala and Zambezia the most notably; as it had paralleled the coast of the latter, stormy conditions were experienced over a much lengthier period there. The heavy, prolonged rain and resultant flooding took 61 people's lives, and the storm caused a total of $170 million in damages.
Tropical Cyclone Enali[]
| Tropical cyclone (MFR) | |
| Category 2 tropical cyclone (SSHWS) | |
  | |
| Duration | 21 January – 25 January |
|---|---|
| Peak intensity | 140 km/h (85 mph) (10-min) 969 hPa (mbar) |
In mid-January, MFR began to track a surface circulation northeast of Mauritius. Its forward speed was slow, with it moving in an erratic but generally westward direction while organizing. Its thunderstorm activity sustained and gradually intensified over the next few days, and after it was discovered to have possessed a closed low-level circulation, it was designated Tropical Depression 06 on 21 January by MFR. It turned southwest and started to intensify, and although its circulation was still relatively broad, it began to tighten up over the next day. At 06:00 UTC on the 22nd, it was further upgraded to moderate tropical storm status, also being given the name Enali. Following dramatic structural improvements that had occurred the day before, the system's intensification rate increased, with it reaching severe tropical storm status 12 hours later. Eventually, early on the 23rd, the JTWC upgraded it to a category 1 tropical cyclone, and a ragged eye began to peek out on visible satellite imagery. Later that day, MFR recognized it as a tropical cyclone, though Enali began to face increasing wind shear. It still intensified some more, attaining category 2 strength at 18:00 UTC that day with 140 km/h (85 mph) winds and a central pressure of 969 mbar (28.61 inHg). However, as vertical wind shear continued to rise and the storm ventured into cooler ocean temperatures, it quickly weakened and initiated an extratropical transition. Within 24 hours after peak, Enali had fallen to tropical storm strength on the Saffir-Simpson scale. It finally lost its tropical status at 12:00 UTC on 25 January, having become a potent extratropical low; thereafter, it slowly weakened as it accelerated to the southeast.
Tropical Depression 07[]
| Tropical depression (MFR) | |
  | |
| Duration | 9 February – 10 February |
|---|---|
| Peak intensity | 55 km/h (35 mph) (10-min) 1005 hPa (mbar) |
Late on 7 February, MFR began to track a disturbance that was sluggishly making its way towards Madagascar. Although it was forecast to move through hostile conditions and therefore was not considered a likely candidate for tropical cyclogenesis, an ASCAT pass and satellite data the following morning showed that it was quickly organizing. A deep convective cluster near the center was noted later that day, and eventually on the 9th, it closed off its circulation. As such, early that day, it was upgraded to a tropical depression, numbered 07S. Because of the storm's proximity to land, it was unable to strengthen much further and made landfall just east of Madagascar's northern tip. 07S then curved southeastward and its thunderstorm activity diminished inland, with MFR issuing their final update on the system early on 10 February. Its remnants continued to track through the remainder of the landmass before ultimately dissipating just offshore.
Being a short-lived and relatively weak system, 07S brought isolated, but in some cases potent, thunderstorms across northern Madagascar. A few of them resulted in particularly high rain rates, leading to peak accumulations of up to about 150 mm (6 in) over a few hours. However, most of the region only reported rainfall totals of around 25 mm (1 in). There were 7 deaths that occurred, and total losses amounted to about $470,000.
Tropical Depression 08[]
| Tropical depression (MFR) | |
  | |
| Duration | 14 February – 14 February (Exited basin) |
|---|---|
| Peak intensity | 55 km/h (35 mph) (10-min) 999 hPa (mbar) |
An area of convection developed in the far eastern portion of the South-West Indian Ocean, being first noted by MFR on 9 February. It was fairly broad and had a poorly-defined circulation, but it was forecast to enter a more favorable environment later on. By the 12th, it started to show more substantial progress towards becoming a tropical cyclone as it tracked over warm waters and tightened its circulation somewhat. However, it still struggled with dry air and failed to organize into a tropical depression until the morning of 14 February, when it was numbered 08S. The system remained fairly stagnant in intensity, eventually crossing into the Australian basin by 18:00 UTC that same day. Tropical Depression 08S would go on to last until the 15th with little change in strength, ultimately dissipating out-to-sea without any impacts.
Intense Tropical Cyclone Fabien[]
| Intense tropical cyclone (MFR) | |
| Category 4 tropical cyclone (SSHWS) | |
  | |
| Duration | 22 February – 1 March |
|---|---|
| Peak intensity | 215 km/h (130 mph) (10-min) 928 hPa (mbar) |
A vigorous zone of disturbed weather was identified in the eastern edge of the basin, drifting steadily southwestward. On 21 February, the JTWC issued a TCFA to recognize that it had a high possibility of developing, and at about 06:00 UTC on the next day, MFR designated it as Tropical Depression 09. Six hours later, it was discovered to have been producing gale-force winds, leading them to upgrade it to a moderate tropical storm and give it the name Fabien. The storm continued to intensify at a fairly robust pace, becoming a severe tropical storm about half a day later. By 12:00 UTC on the 23rd, it became a category 1 tropical cyclone according to the JTWC, with MFR upgrading it to an equivalent status later that day; at this time, Fabien had begun to clear out a fairly small eye, and satellite data supported category-1 intensity. It then underwent a period of rapid intensification, with its 10-minute winds increasing from 110 km/h (70 mph) to 205 km/h (125 mph) in 24 hours. It strengthened a little bit more to reach its first peak intensity, housing a minimum central pressure of 944 hPa (27.88 inHg); however, it weakened shortly thereafter due to an eyewall replacement cycle taking place. After completing it, Fabien recovered and intensified once moere to reach its overall peak intensity, consisting of 215-km/h (130 mph) 10-minute winds and a pressure of 928 hPa (27.40 inHg). It maintained this strength for another 12 hours or so before starting to gradually weaken due to falling ocean temperatures, and its wind speed decreased to category 3-equivalent status at 00:00 UTC on 27 February. It continued to deteriorate, with its eye filling in later that day, and it eventually dipped below major tropical cyclone strength. By midday on the 28th, it fell to a high-end tropical storm, and the following day, it became a weak depression that ultimately transitioned into a remnant low by the end of the day.
Moderate Tropical Storm Anggrek[]
| Moderate tropical storm (MFR) | |
| Tropical storm (SSHWS) | |
  | |
| Duration | 27 February (Entered basin) – 1 March |
|---|---|
| Peak intensity | 85 km/h (50 mph) (10-min) 990 hPa (mbar) |
At around 18:00 UTC on 27 February, Cyclone Anggrek passed from TCWC Jakarta’s area of responsibility into the South-West Indian Ocean. Immediately upon crossing over, it was designated as a moderate tropical storm by MFR, with estimated 10-minute sustained winds of 75 km/h (45 mph). Due to favorable ocean temperatures along with a lack of wind shear, it intensified slightly, peaking with winds just under the severe tropical storm classification; additionally, it had peaked with a pressure of 990 hPa (29.23 inHg). Anggrek took a south turn afterwards and encountered a less conducive environment, causing it to weaken to tropical depression strength early on 1 March. Throughout the day, the storm took on an increasingly sheared appearance and struggled to maintain a central cluster of thunderstorm activity, with it eventually becoming nearly devoid of convection in general by the end of the day. By the beginning of 2 March, MFR issued its final advisory on the now-naked swirl, marking it as no longer a tropical cyclone.
Zone of Disturbed Weather 10[]
| Zone of Disturbed Weather | |
  | |
| Duration | 9 March – 10 March |
|---|---|
| Peak intensity | 45 km/h (30 mph) (10-min) 1006 hPa (mbar) |
MFR noted a disturbance emerging off the coast of Mozambique on 7 March, acknowledging a possible window for tropical development before it moved back inland over Madagascar. The JTWC also began to monitor the system for potential development a few days afterwards, tagging it as 94S. On the 9th, it was formally recognized as Zone of Disturbed Weather 10 by MFR. That same day, it peaked with a moderate chance of coalescing into a tropical cyclone since it showed continuous improvement in its structure and was forecast to move over increasingly favorable ocean temperatures; however, wind shear in the area ended up being stronger than expected, causing it to struggle to organize further. It failed to produce organized convection around the center, with much of it being sheared away, and it eventually moved inland at about 06:00 UTC on 10 March. By then, its chances for development formally ended, though it remained a traceable system until it was around halfway across the country; thereafter, MFR no longer tracked it.
Tropical Cyclone Gezani[]
| Tropical cyclone (MFR) | |
| Category 2 tropical cyclone (SSHWS) | |
  | |
| Duration | 18 March – 23 March |
|---|---|
| Peak intensity | 140 km/h (85 mph) (10-min) 972 hPa (mbar) |
A surface low developed several hundred miles east of northern Madagascar, steadily moving southeast. Despite originally unfavorable conditions, the JTWC marked it as having a moderate chance of development on the 16th, as it showed signs of significant organization. This trend continued, causing the low to eventually have a Tropical Cyclone Formation Alert (TCFA) issued for it late on the following day. It officially attained tropical depression status per MFR’s analysis at 06:00 UTC on the 18th. Gales were not found in the system at first, leading to it maintaining such intensity for about a day, until a scatterometer pass on the 19th finally indicated 35-kt winds occurring near the center of it. This prompted MFR to name it Moderate Tropical Storm Gezani early that day, with it also being tagged as Tropical Cyclone 11S by the JTWC. It curved to the west and picked up its pace of intensification, reaching severe tropical storm status a little under a day later. Due to continued structural improvements, along with the appearance of an eye, it later reached category 1 tropical cyclone strength at 12:00 UTC on the 20th per the JTWC’s scale. Another several hours later, it had attained category 2-equivalent status, ultimately peaking with a pressure of 972 mbar (28.70 inHg) and 10-minute winds of 145 km/h (85 mph). This intensity was retained for a good chunk of the day, as environmental conditions gradually became less favorable, and Gezani eventually began to decline as it accelerated southeastward. Its central convection weakened somewhat as it encountered lower ocean temperatures, and its eye filled in rather quickly. It fell back to tropical storm strength by 18:00 UTC on 22 March, eventually losing tropical cyclone status as a whole 18 hours later.
Moderate Tropical Storm Horacio[]
| Moderate tropical storm (MFR) | |
| Tropical storm (SSHWS) | |
  | |
| Duration | 29 March – 4 April |
|---|---|
| Peak intensity | 85 km/h (50 mph) (10-min) 985 hPa (mbar) |
- Main article: Tropical Storm Horacio (Zeta)
On 26 March, MFR marked an area of convection for potential development east of Madagascar. It originally showed little change in appearance, so it was maintained at a low probability of formation; however, it soon entered a small area of very above-average ocean temperatures, allowing it to rapidly coalesce just before reaching land. As such, it was classified as Tropical Depression 12 at 12:00 UTC on 29 March. It eventually strengthened into Moderate Tropical Storm Horacio at the beginning of the following day, though since it had already been approaching the eastern coast of Madagascar, it made landfall almost immediately after reaching said status. It did so with an initial peak pressure of 994 hPa (29.35 inHg) and maximum 10-minute winds of 65 km/h (40 mph), though it weaken quickly afterwards due to land interaction. It fell back to tropical depression strength by the end of the day, ultimately degenerating back into a low pressure area a few hours later due to it lacking sufficient convection and an overall significant loss in organization. Later on the 31st, the remnants of Horacio drifted back over water and slowly began to reorganize, with them being marked for a high chance of re-development by 1 April. Eventually, the system was upgraded to a tropical depression once more at 12:00 UTC on the 2nd, with it further re-strengthening to a moderate tropical storm later on. At this time, although it began to initiate an extratropical transition, it attained its all-time peak intensity of 85 km/h (50 mph) and minimum central pressure of 985 hPa (29.09 inHg). Shortly after peak, MFR reclassified it as a subtropical cyclone as it continued southeastward, with it maintaining this designation for another 30 hours. By 4 April, the system was considered to have completed its transition into an extratropical cyclone, and as such, MFR issued its final advisories on Horacio.
During the first part of Horacio’s existence, it brought some impacts to eastern Madagascar, namely high winds, some storm surge, and minor flooding. Residents of the area were caught somewhat off-guard by its quick spin-up near the coast, though the storm still did not cause any severe impacts; although over 10 cm (4 in) of rainfall accumulations were recorded in some locations closest to Horacio’s center, most regions did not see rain totals come close to this number. Still, there were 15 deaths reported in association with the storm’s impacts, and total damage was placed at $1.8 million (2023 USD).
Storm names[]
Within the South-West Indian Ocean, (sub)tropical cyclones that are judged to have 10-minute sustained winds of 65 km/h (40 mph) by the Regional Specialized Meteorological Center on Réunion island, France (RSMC La Réunion) are usually assigned a name. However, the Sub-Regional Tropical Cyclone Advisory Centers in Mauritius and Madagascar are the ones to actually name the systems. The Sub-Regional Tropical Cyclone Advisory Center (Mauritius Meteorological Services) in Mauritius names a storm if it intensifies into a moderate tropical storm between 55°E and 90°E; if instead a cyclone intensifies into a moderate tropical storm between 30°E and 55°E, then the Sub-Regional Tropical Cyclone Advisory Center (Madagascar Meteorological Services) in Madagascar assigns the appropriate name to the storm. Storm names are taken from three pre-determined lists of names, which rotate on a triennial basis, with any names that have been used automatically removed. Therefore, all storm names used this year will be removed from the rotation and replaced with a new name for the 2025–26 season, while the unused names will remain on the list. New names this season are: Ashley, Balita, Cheneso, Dingani, Enali, Fabien, Gezani, Horacio, Indusa, and Juluka; they replaced Ambali, Belna, Calvinia, Diane, Esami, Francisco, Gabekile, Herold, Irondro, and Jeruto after the 2019–20 season. The entire list of names for this year is shown below.
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Any tropical cyclones that cross into the South-West Indian Ocean from the Australian region retain their names from the basins they formed in. In the 2022-23 season, the following storms crossed into this basin.
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Naming scheme changes[]
After the 2022-23 season, it was decided that the naming scheme for South-West Indian Ocean tropical cyclones would be slightly revamped. Although the names in each list are the same, only storms that cause considerable death or loss of life will be replaced, while the others remain in circulation for later usage. In addition, rather than starting fresh on a new list every year, each season’s naming list would rotate without regard to year; for instance, if one season concluded on a name that started with J, the next season would begin on that same list, starting with the K-name. The 2022-23 season would retroactively follow this new policy, meaning that the following season began with the name Indusa; also, no names were retired from this season. This revamp was put in place to prevent large quantities of names from being drawn up each year, as well as to have the entirety of each list be used.
Season effects[]
This table lists any tropical cyclones that took place during the 2022-23 South-West Indian Ocean cyclone season. It includes information about their intensity, duration, impacted areas, deaths, and damage reports. Damage totals are given in 2022 or 2023 USD, depending on when the storm existed.
| Name | Dates active | Peak classification | Sustained wind speeds |
Pressure | Areas affected | Damage (USD) |
Deaths | Refs |
|---|---|---|---|---|---|---|---|---|
| Ashley | 27 November – 1 December | Tropical cyclone | 120 km/h (75 mph) | 976 hPa (28.82 inHg) | Madagascar | Minimal | None | |
| Balita | 7 – 10 December | Moderate tropical storm | 85 km/h (50 mph) | 992 hPa (29.29 inHg) | None | None | None | |
| Ellie | 11 – 12 December | Severe tropical storm | 95 km/h (60 mph) | 981 hPa (28.97 inHg) | None | None | None | |
| Cheneso | 24 – 30 December | Intense tropical cyclone | 205 km/h (125 mph) | 933 hPa (27.55 inHg) | Rodrigues | $1.1 million | 13 | |
| 04 | 04 – 05 January | Tropical depression | 55 km/h (35 mph) | 1002 hPa (29.59 inHg) | None | None | None | |
| Dingani | 15 – 18 January | Severe tropical storm | 95 km/h (60 mph) | 980 hPa (28.94 inHg) | Mozambique, Malawi | $170 million | 61 | |
| Enali | 21 – 25 January | Tropical cyclone | 140 km/h (85 mph) | 969 hPa (28.61 inHg) | None | None | None | |
| 07 | 9 – 10 February | Tropical depression | 55 km/h (35 mph) | 1005 hPa (29.68 inHg) | Madagascar | $470,000 | 7 | |
| 08 | 14 February | Tropical depression | 55 km/h (35 mph) | 999 hPa (29.50 inHg) | None | None | None | |
| Fabien | 22 February – 1 March | Intense tropical cyclone | 215 km/h (130 mph) | 928 hPa (27.40 inHg) | None | None | None | |
| Anggrek | 27 February – 1 March | Moderate tropical storm | 85 km/h (50 mph) | 990 hPa (29.23 inHg) | None | None | None | |
| 10 | 9 – 10 March | Zone of disturbed weather | 45 km/h (30 mph) | 1006 hPa (29.71 inHg) | Madagascar | Minimal | None | |
| Gezani | 18 – 23 March | Tropical cyclone | 140 km/h (85 mph) | 972 hPa (28.70 inHg) | None | None | None | |
| Horacio | 29 March – 4 April | Moderate tropical storm | 85 km/h (50 mph) | 985 hPa (29.09 inHg) | Madagascar | $1.8 million | 15 | |
| Season aggregates | ||||||||
| 14 systems | 27 November – 4 April | 215 km/h (130 mph) | 928 hPa (27.40 inHg) | $173.37 million | 96 | |||
See also[]
- Tropical cyclones in 2022, 2023
- Atlantic hurricane seasons: 2022, 2023
- Pacific hurricane seasons: 2022, 2023
- Pacific typhoon seasons: 2022, 2023
- North Indian Ocean cyclone seasons: 2022, 2023
- 2022-23 Australian region cyclone season (Zeta)
- 2022-23 South Pacific cyclone season (Zeta)