2023–24 Australian Region Cyclone Season
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The 2023–24 Australian region cyclone season was the fifth and final consecutive season to have below-average activity in terms of named storms. Despite this, it was the second in a row to have at least five severe tropical cyclones, including Australia's wettest tropical cyclone on record. The season officially started on 1 November 2023 and ended on 30 April 2024, however, a tropical cyclone could form at any time between 1 July 2023 and 30 June 2024 and would count towards the season total. During the season, tropical cyclones were officially monitored by one of the three tropical cyclone warning centres (TCWCs) for the region which are operated by the
Australian Bureau of Meteorology The Bureau of Meteorology (BOM or BoM) is an executive agency of the Australian Government that is responsible for providing weather forecasts and meteorological services to Australia and neighbouring countries. It was established in 1906 unde ...
, National Weather Service of
Papua New Guinea Papua New Guinea, officially the Independent State of Papua New Guinea, is an island country in Oceania that comprises the eastern half of the island of New Guinea and offshore islands in Melanesia, a region of the southwestern Pacific Ocean n ...
and the
Indonesian Agency for Meteorology, Climatology and Geophysics Meteorology, Climatology, and Geophysical Agency (, abbreviated BMKG) is an Indonesian non-departmental government agency for meteorology, climatology, and geophysics. History Its history began on 1841 with individual observation conducted by ...
. The United States
Joint Typhoon Warning Center The Joint Typhoon Warning Center (JTWC) is a joint United States Navy – United States Air Force command in Pearl Harbor, Hawaii. The JTWC is responsible for the issuing of tropical cyclone warnings in the North-West Pacific Ocean, South P ...
(JTWC) and other national meteorological services including
Météo-France Météo-France is the official French meteorological administration, also offering services to Andorra and Monaco. It has the powers of the state and can exercise them in relation to meteorology. Météo-France is in charge of observing, study ...
and the
Fiji Meteorological Service The Fiji Meteorological Service (FMS) is a Department of the government of Fiji responsible for providing weather forecasts and is based on the grounds of Nadi Airport in Nadi. The current director of Fiji Meteorological Service is Misaeli Funak ...
will also monitor the basin during the season. __TOC__


Season forecasts

Ahead of the season officially starting on 1 November, the Australian
Bureau of Meteorology The Bureau of Meteorology (BOM or BoM) is an executive agency of the Government of Australia, Australian Government that is responsible for providing Weather forecasting, weather forecasts and Meteorology, meteorological services to Australia a ...
(BoM) and New Zealand's
National Institute of Water and Atmospheric Research The National Institute of Water and Atmospheric Research or NIWA (), is a Crown Research Institute of New Zealand. Established in 1992, NIWA conducts research across a broad range of disciplines in the environmental sciences. It also maintai ...
(NIWA) both issued a tropical cyclone outlook that discussed the upcoming season. These outlooks took into account a variety of factors such as a developing El Niño event and what had happened in previous seasons such as
1972–73 Year 197 ( CXCVII) was a common year starting on Saturday of the Julian calendar. At the time, it was known as the Year of the Consulship of Magius and Rufinus (or, less frequently, year 950 ''Ab urbe condita''). The denomination 197 for this y ...
, 1982–83, 1997–98, 2009–10 and 2015–16. Within their seasonal outlook for the Australian region, the BoM suggested that there was an 80% chance, that the whole region between 90°E – 160°E, would be below average, having less than the long term average of 11 tropical cyclones. They also suggested that each of their self-defined Western, Northern, North-western and Eastern regions would see a below-average amount of tropical cyclone activity. The BoM also issued a seasonal forecast that discussed tropical cyclone activity over the South Pacific Ocean for their self-defined eastern and western regions of the South Pacific Ocean. Within this forecast, they predicted that their western region between 142.5°E and 165°E would have a below average amount of activity, while their eastern region between 165°E and 120°W had a 60% chance of seeing activity above its average of 6 tropical cyclones. Along with other Pacific Meteorological Services, the BoM contributed to NIWA's Southwest Pacific tropical cyclone outlook, which predicted that nine and fourteen tropical cyclones would occur between 135°E and 120°W. At least four to eight of these systems were expected to intensify further and become either a Category 3, 4 or 5 severe tropical cyclone on the Australian tropical cyclone intensity scale.


Season summary


Early activity

The season officially started on 1 November, however the first system,
Cyclone Jasper Severe Tropical Cyclone Jasper was the wettest tropical cyclone in Australian history, surpassing Cyclone Peter, Peter of 1979. The third disturbance of the 2023–24 South Pacific cyclone season and the first named storm and severe tropical cy ...
, would not be active until 4 December, when it crossed into the basin as a tropical low from the South Pacific. The low became a named storm on 5 December, receiving the name ''Jasper'', and intensified into the season's first severe tropical cyclone the next day. Jasper made landfall in Far North Queensland as a Category 2 tropical cyclone on 13 December.


Season starts

After a significant lull in activity, Tropical Cyclone Anggrek and Tropical Low 03U formed on 10 and 11 January respectively, with the latter dissipating on 23 January. The next day,
Cyclone Kirrily Severe Tropical Cyclone Kirrily was a long-lived and strong tropical cyclone that affected East Australia and the Northern Territory during January and February 2024. The third named storm and severe tropical cyclone of the 2023–24 Australian r ...
formed. Tropical Low 06U formed on 30 January, dancing out of basin the next day and waltzing back in on 5 February. Tropical Cyclone Lincoln formed on 16 February and made landfall on the Gulf of Carpentaria coast. Severe Tropical Cyclone Neville formed north of the
Cocos Islands The Cocos (Keeling) Islands (), officially the Territory of Cocos (Keeling) Islands (; ), are an Australian external territory in the Indian Ocean, comprising a small archipelago approximately midway between Australia and Sri Lanka and rel ...
on 1 March and left the basin 20 days later. Severe Tropical Cyclone Megan formed on 13 March from a tropical low over the coast of the Gulf of Carpentaria. Short-lived Tropical Low 10U formed and weakened within the same day of 14 March. Severe Tropical Cyclone Olga formed within a monsoon trough south of
Sumba Sumba (; ), natively also spelt as Humba, Hubba, Suba, or Zuba (in Sumba languages) is an Indonesian island (part of the Lesser Sunda Archipelago group) located in the Eastern Indonesia and administratively part of the East Nusa Tenggara pro ...
on 4 April. Tropical Cyclone Paul formed 5 days later over the
Louisiade Archipelago The Louisiade Archipelago is a string of ten larger volcanic islands frequently fringed by coral reefs, and 90 smaller coral islands in Papua New Guinea. It is located 200 km southeast of New Guinea, stretching over more than and spread o ...
. Tropical Low 12U formed on 12 April and remained traceable.


Off-season

The season ended with Tropical Low 16U, formed on 4 May and weakened the next day.


Systems


Severe Tropical Cyclone Jasper

On 2 December, the Australian
Bureau of Meteorology The Bureau of Meteorology (BOM or BoM) is an executive agency of the Government of Australia, Australian Government that is responsible for providing Weather forecasting, weather forecasts and Meteorology, meteorological services to Australia a ...
(BoM) reported that Tropical Disturbance 03F, which was re-designated as Tropical Low 02U, had formed in the
South Pacific Ocean South is one of the cardinal directions or compass points. The direction is the opposite of north and is perpendicular to both west and east. Etymology The word ''south'' comes from Old English ''sūþ'', from earlier Proto-Germanic ''*sunþa ...
in Fiji's area of responsibility. Two days later, on 00:00 UTC of 4 December, the system would enter the Australian area of responsibility. The
Joint Typhoon Warning Center The Joint Typhoon Warning Center (JTWC) is a joint United States Navy – United States Air Force command in Pearl Harbor, Hawaii. The JTWC is responsible for the issuing of tropical cyclone warnings in the North-West Pacific Ocean, South P ...
(JTWC) issued a
Tropical Cyclone Formation Alert A Tropical Cyclone Formation Alert (TCFA) is a bulletin released by the U.S. Navy-operated Joint Typhoon Warning Center in Honolulu, Hawaii or the Fleet Weather Center in Norfolk, Virginia, warning of the possibility of a tropical cyclone formi ...
(TCFA) later that day, projecting a high likelihood of a significant tropical cyclone developing. Later the next day, the JTWC subsequently initiated advisories on the system and classified it as Tropical Cyclone 03P. The BoM subsequently followed suit and upgraded it to a Category 1 tropical cyclone, naming it ''Jasper''. Jasper started to track southward under the steering influence of a near equatorial ridge to the east. During the next day, the cyclone's centre continued to organise, with deep convective bands starting to wrap around the centre, prompting the JTWC to upgrade the system to a
Category 1 hurricane Category, plural categories, may refer to: General uses *Classification, the general act of allocating things to classes/categories Philosophy *Category of being * ''Categories'' (Aristotle) *Category (Kant) *Categories (Peirce) *Category (Vais ...
. Jasper rapidly intensified into a Category 3 severe tropical cyclone, due to being in an environment with warm
sea surface temperature Sea surface temperature (or ocean surface temperature) is the ocean temperature, temperature of ocean water close to the surface. The exact meaning of ''surface'' varies in the literature and in practice. It is usually between and below the sea ...
s and low
wind shear Wind shear (; also written windshear), sometimes referred to as wind gradient, is a difference in wind speed and/or direction over a relatively short distance in the atmosphere. Atmospheric wind shear is normally described as either vertical ...
. The next day, it further intensified, becoming a Category 5 severe tropical cyclone. Operationally, the BoM classified Jasper as a high-end Category 4 severe tropical cyclone with winds of , but during post-cyclone reanalysis concluded a peak wind speed of based on
Synthetic-aperture radar Synthetic-aperture radar (SAR) is a form of radar that is used to create two-dimensional images or three-dimensional reconstructions of objects, such as landscapes. SAR uses the motion of the radar antenna over a target region to provide fine ...
measurements. Shortly thereafter, Jasper began weakening, with its eye becoming cloud-filled and the deep convection eroding due to dry air entrainment. Jasper would reintensify, and at 12:00 UTC on 13 December, made landfall as a Category 2 tropical cyclone in
Wujal Wujal Wujal Wujal, sometimes spelt Wudjil Wudjil, is a rural town and locality in the Wujal Wujal Aboriginal Shire, Queensland, Australia. It is an Aboriginal community. In the , the locality of Wujal Wujal had a population of 276 people. The comm ...
, Queensland.Cyclone Jasper makes landfall in Australia
". ''AFP''. 13 December 2023.
After making landfall, the JTWC discontinue warnings on the system later that day. By 14:00 UTC that day, the BoM reported that Jasper had weakened to a tropical low. However, Jasper remained traceable, and the BoM would give the tropical low a moderate chance of redeveloping into a tropical cyclone on 15 December. However, they would soon downgrade its chances of re-developing into a very low as the storm turned southeast further inland, causing the tropical low to rapidly weaken, and on 18 December, Jasper was last noted over the Cape York Peninsula. Jasper produced torrential rainfall, peaking at at Bairds near the Daintree River, making the wettest
tropical cyclone A tropical cyclone is a rapidly rotating storm system with a low-pressure area, a closed low-level atmospheric circulation, strong winds, and a spiral arrangement of thunderstorms that produce heavy rain and squalls. Depending on its locat ...
in Australian history, beating the previous record of
Cyclone Peter Severe Tropical Cyclone Peter was at the time, the wettest tropical cyclone on record in Australia, until it was surpassed by Cyclone Jasper in 2023. The third system and first severe tropical cyclone of the 1978–79 season, Peter developed ...
in 1979. The Insurance Council of Australia estimated that Jasper caused AU$1 billion (US$670 million) in damages.


Severe Tropical Cyclone Anggrek

On 9 January, the BoM noted that a tropical low could form in the
Indian Ocean The Indian Ocean is the third-largest of the world's five oceanic divisions, covering or approximately 20% of the water area of Earth#Surface, Earth's surface. It is bounded by Asia to the north, Africa to the west and Australia (continent), ...
, designating it as 04U. Later the next day, the BoM reported that it had formed to the northwest of the
Cocos Islands The Cocos (Keeling) Islands (), officially the Territory of Cocos (Keeling) Islands (; ), are an Australian external territory in the Indian Ocean, comprising a small archipelago approximately midway between Australia and Sri Lanka and rel ...
. On 11 January, the JTWC followed suit in monitoring the system, after convection had significantly consolidated around the circulation. Three days later, the agency issued a TCFA, for the disturbance as it was situated in an environment of warm waters, low shear, and good outflow. By 15 January, the JTWC began issuing advisories, recognising it as Tropical Cyclone 06S after its circulation had improved, with the BoM subsequently followed suit and upgraded it to a Category 1 tropical cyclone. Since the cyclone was within their area of responsibility,
Meteorology, Climatology, and Geophysical Agency Meteorology, Climatology, and Geophysical Agency (, abbreviated BMKG) is an Indonesian non-departmental government agency for meteorology, climatology, and geophysics. History Its history began on 1841 with individual observation conducted by ...
(BMKG) named the system ''Anggrek''. It tracked southeast before changing direction and tracking west. Anggrek remained nearly stationary due to weak steering ridges to the north and southwest, the system generated
upwelling Upwelling is an physical oceanography, oceanographic phenomenon that involves wind-driven motion of dense, cooler, and usually nutrient-rich water from deep water towards the ocean surface. It replaces the warmer and usually nutrient-depleted sur ...
, causing sea surface temperatures to decrease. Despite that, Anggrek steadily re-intensified, and after entering favourable conditions on 24 January, became a Category 3 severe tropical cyclone, with estimated maximum 10-minute sustained winds of , and a central barometric pressure of . while the system's depiction showed that tightly circulating around a ragged eye. The next day, the system exited the basin towards the South West Indian Ocean.


Tropical Low 03U

On 7 January, the BoM noted the possibility of a tropical low forming near the north
Kimberley Kimberly or Kimberley may refer to: Places and historical events Australia Queensland * Kimberley, Queensland, a coastal locality in the Shire of Douglas South Australia * County of Kimberley, a cadastral unit in South Australia Ta ...
, as a
monsoon trough The monsoon trough is a convergence zone between the wind patterns of the southern and northern hemispheres. It is a portion of the Intertropical Convergence Zone in the Western Pacific,Bin WangThe Asian Monsoon.Retrieved 2008-05-03. and is dep ...
was expected to develop along the
Top End The Top End of Australia's Northern Territory is a geographical region encompassing the northernmost section of the Northern Territory, which aside from the Cape York Peninsula is the northernmost part of the Australian continent. It covers a ...
. It was predesignated as 03U. This came to fruition 4 days later, when the BoM reported that it was developing over the southern
Joseph Bonaparte Gulf Joseph Bonaparte Gulf is a large body of water off the coast of the Northern Territory and Western Australia and part of the Timor Sea. It was named after Joseph Bonaparte, brother of Napoleon and King of Naples (1806–1808) and then Spain (18 ...
within the trough. As the tropical low tracked overland, the system maintained a robust outflow channel in the upper troposphere. The BoM continued to monitor the low as it moved slowly southeast, then turning west towards Western Australia by 20 January, until they determined that it would not develop into a tropical cyclone on 23 January. The low and its associated monsoon brought heavy rainfall to the Northern Territory, resulting in the BoM issuing flood watches and warnings throughout the Top End and central Northern Territory.
Wadeye Wadeye ( ) is a town in Australia's Northern Territory (NT). It was formerly known (and is still often referred to) as Port Keats, a name originating from Port Keats Mission, which operated from 1935 (originally at a different location, known as ...
received of rainfall.


Severe Tropical Cyclone Kirrily

The BoM noted the possibility of a tropical low forming within the monsoon trough over the
Gulf of Carpentaria The Gulf of Carpentaria is a sea off the northern coast of Australia. It is enclosed on three sides by northern Australia and bounded on the north by the eastern Arafura Sea, which separates Australia and New Guinea. The northern boundary ...
on 9 January, designating it as 05U. Three days later, the BoM reported that it was developing over the eastern portion of the gulf. By 17 January, the JTWC began monitoring the low. Two days later, the JTWC issued a TCFA for the system. By 21 January, the BoM started issuing warnings on the system. By 23 January, the JTWC followed suit, recognising it as Tropical Cyclone 07P.Alt URL
/ref> The next day, the BoM upgraded the low into a Category 1 tropical cyclone, naming it ''Kirrily''. Deep convection shifted to the western side of Kirrily's circulation, though its centre remained well defined. It subsequently intensified to a Category 3 severe tropical cyclone, the JTWC followed suit the system and upgraded it to a Category 1 hurricane, prior to landfall over
Townsville, Australia The City of Townsville is a city on the north-eastern coast of Queensland, Australia. With a population of 201,313 as of 2024, it is the largest settlement in North Queensland and Northern Australia (specifically, the parts of Australia north of ...
on 25 January. Shortly after the landfall, the JTWC discontinued warnings on the system. The next day, the BoM discontinued warnings. However, Kirrily remained traceable, as it moved westwards towards the
Queensland Queensland ( , commonly abbreviated as Qld) is a States and territories of Australia, state in northeastern Australia, and is the second-largest and third-most populous state in Australia. It is bordered by the Northern Territory, South Austr ...
region throughout the rest of January. The JTWC began monitoring the remnants of Kirrily for potential regeneration as the system developed a partially exposed low-level circulation centre (LLCC). Early the next day, they issued a TCFA for the remnants. The disturbance later regenerated into a tropical cyclone; the system showed a consolidating LLCC with convective banding and a
central dense overcast The central dense overcast, or CDO, of a tropical cyclone or strong subtropical cyclone is the large central area of thunderstorms surrounding its circulation center, caused by the formation of its eyewall. It can be round, angular, oval, or ir ...
(CDO). Since the system only produced near- gale-force winds in the Gulf of Carpentaria, the BoM determined that the low was not expected to redevelop into a tropical cyclone. By 2 February, the JTWC discontinued their advisories again, as the storm accelerated inland with the rainbands unraveling and warming cloud tops, until it was last noted on the BoM tropical cyclone outlooks by the next day. Before the storm made landfall on 24 January, the BoM issued cyclone warnings for Townsville, Mackay, Bowen, the Whitsunday Islands, which extended inland to Charters Towers. As the storm impacted Queensland, locally intense rainfall up to was recorded.


Tropical Low 06U

On 29 January, the BoM noted that a subtropical low was expected to form off the coast of Eastern Australia in a few days, designating it as 06U. The next day, the BoM began monitoring the low as it was developing in the eastern portion of the basin, about to the northeast of Kgari in Queensland, Australia. Over the next couple of days, the system moved north-eastwards and moved into the South Pacific basin during 1 February, where it was classified as Tropical Disturbance 05F by the Fiji Meteorological Service. At this stage, the system was located in an area of moderate vertical
wind shear Wind shear (; also written windshear), sometimes referred to as wind gradient, is a difference in wind speed and/or direction over a relatively short distance in the atmosphere. Atmospheric wind shear is normally described as either vertical ...
and good upper-level
divergence In vector calculus, divergence is a vector operator that operates on a vector field, producing a scalar field giving the rate that the vector field alters the volume in an infinitesimal neighborhood of each point. (In 2D this "volume" refers to ...
about to the northwest of Nouméa in New Caledonia, while
atmospheric convection Atmospheric convection is the vertical transport of heat and moisture in the atmosphere. It occurs when warmer, less dense air rises, while cooler, denser air sinks. This process is driven by parcel-environment instability, meaning that a "par ...
persisted over the system's LLCC. After meandering outside the basin for several days, the system re-entered the basin as a tropical low. Environmental conditions were assessed as being marginally conducive for
tropical cyclogenesis Tropical cyclogenesis is the development and strengthening of a tropical cyclone in the atmosphere. The mechanisms through which tropics, tropical cyclogenesis occur are distinctly different from those through which temperate cyclogenesis occu ...
, with warm
sea surface temperature Sea surface temperature (or ocean surface temperature) is the ocean temperature, temperature of ocean water close to the surface. The exact meaning of ''surface'' varies in the literature and in practice. It is usually between and below the sea ...
s near and low
vertical wind shear Wind shear (; also written windshear), sometimes referred to as wind gradient, is a difference in wind speed and/or direction over a relatively short distance in the atmosphere. Atmospheric wind shear is normally described as either vertical o ...
. It again exited the basin on 7 February, as the storm was struggling due to moderate wind shear.


Tropical Cyclone Lincoln

During February 2024, the presence of the
Madden–Julian Oscillation The Madden–Julian oscillation (MJO) is the largest element of the intraseasonal (30- to 90-day) variability in the tropical atmosphere. It was discovered in 1971 by Roland Madden and Paul Julian of the American National Center for Atmospheric ...
and an equatorial
Indian Ocean The Indian Ocean is the third-largest of the world's five oceanic divisions, covering or approximately 20% of the water area of Earth#Surface, Earth's surface. It is bounded by Asia to the north, Africa to the west and Australia (continent), ...
in the Australian region contributed to the formation of Tropical Low 07U in the
monsoon trough The monsoon trough is a convergence zone between the wind patterns of the southern and northern hemispheres. It is a portion of the Intertropical Convergence Zone in the Western Pacific,Bin WangThe Asian Monsoon.Retrieved 2008-05-03. and is dep ...
over the western Gulf of Carpentaria, approximately to the east-southeast of Darwin in the
Northern Territory The Northern Territory (abbreviated as NT; known formally as the Northern Territory of Australia and informally as the Territory) is an states and territories of Australia, Australian internal territory in the central and central-northern regi ...
during 14 February. Initially located in an favourable environment for intensification, the tropical low began to encounter somewhat improved conditions. As the tropical low tracked slowly moving towards the coast, consolidating LLCC with convection started to develop and was wrapping toward the centre. By 15 February, at 14:30 UTC, the JTWC issued a TCFA, noting that the system was in a favourable environment with low wind shear and sea surface temperatures exceeding . The agency later issued its first warning on the system, classifying it as Tropical Cyclone 14P. The BoM followed suit—officially upgrading the system to a Category 1 tropical cyclone and assigning the name ''Lincoln''. Lincoln had a partially exposed LLCC with core convection confined to the western edge of the cyclone. Lincoln made landfall on the Gulf of Carpentaria coast between Port McArthur and the Northern Territory—Queensland border just after 06:00 UTC on 16 February. Shortly after the landfall, the JTWC discontinued warnings on the system. Later that day, the BoM followed suit and released its last advisory as the system degenerated into a tropical low. However, Lincoln remained traceable, and the BoM would give the system a high chance of redeveloping into a tropical cyclone on 18 February. The following day, the tropical low continued moving west-southwest, aided by a
ridge A ridge is a long, narrow, elevated geomorphologic landform, structural feature, or a combination of both separated from the surrounding terrain by steep sides. The sides of a ridge slope away from a narrow top, the crest or ridgecrest, wi ...
to the south, across inland parts of the Northern Territory. By 21 February, the remnants of Lincoln turned westward into the offshore of the Kimberley coast and began to re-organise, resulting deep convection to the north. The JTWC re-issued a TCFA for the system at 07:30 UTC as the formative convective banding was wrapping into a defined circulation. With an increase in convective banding on the southern of the cyclone's circulation, the JTWC re-initiated advisories on the storm approximately northeast of Learmonth at 03:00 UTC on 22 February. Turning northwest as it approached
Western Australia Western Australia (WA) is the westernmost state of Australia. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to the south, the Northern Territory to the north-east, and South Australia to the south-east. Western Aust ...
, the storm failed to organised its deep convection. By 24 February, the JTWC subsequently issued their final advisory on the system, as its circulation became exposed. The storm then crossed just south of Coral Bay on the Australian northwestern coastline just after 12:00 UTC that day, before moving inland across
Gascoyne The Gascoyne region is one of the nine regions of Western Australia. It is located in the northwest of Western Australia, and consists of the local government areas of Carnarvon, Exmouth, Shark Bay and Upper Gascoyne. The Gascoyne has about of ...
and dissipating shortly afterward. Tropical Cyclone Lincoln was the first tropical cyclone to form in the Gulf of the Carpentaria since Tropical Cyclone Alfred in February 2017. Lincoln brought heavy rainfall to Carnavon. The town of Gascoyne faced moderate agricultural losses during the storm, with one farmer losing AU$40,000 (US$25,000).


Severe Tropical Cyclone Neville

On 1 March, the BoM started to monitor a possible tropical low to the north of the
Cocos Islands The Cocos (Keeling) Islands (), officially the Territory of Cocos (Keeling) Islands (; ), are an Australian external territory in the Indian Ocean, comprising a small archipelago approximately midway between Australia and Sri Lanka and rel ...
within the monsoon trough, designating it as 08U. An increased monsoon flow over the Indian Ocean towards Indonesia prompted the agency to report that the tropical low was forming on 4 March, within an unfavourable environment for further development. By 10 March, the JTWC issued a TCFA for the tropical low after noting that its deep convection continued to build in the southern and central regions over the system's LLCC, and the next day, it recognised the system as Tropical Cyclone 18S. Afterwards, subsidence and high vertical wind shear caused the system to struggle to intensify, leaving the LLLC exposed. Although convection continued to fluctuate in the system, deep convection continued to improve near the centre. By 18 March, the JTWC subsequently issued their final advisory on the system, as its structure was to be disorganised. During the next day, the tropical low began to displace to the south of the LLLC, the JTWC resumed monitoring the system. The LLCC started to re–develop with deep convective bands wrapping into it, the JTWC re-initiated advisories approximately northwest of Learmonth at 03:00 UTC on 20 March. Later that day, the BoM reported that the tropical low had developed into a Category 1 tropical cyclone and named it ''Neville''. Neville intensified shortly after, with an eye forming on microwave imagery. A pinhole eye briefly emerged on infrared and visible satellite imagery as a ragged feature at the cyclone's centre, surrounded by well-defined rainbands. Neville reached peak intensity at 06:00 UTC the following day as a high-end Category 4 severe tropical cyclone, with ten-minute sustained winds estimated at , and a central barometric pressure of . The JTWC estimated that the system was generating one-minute sustained winds of , equivalent to a low-end Category 4 major hurricane. Afterward, the storm's eye becoming cloud-filled caused Neville to gradually weaken as its track shifted west-southwestward. Neville's eye disappeared from satellite imagery and the cloud tops of the
central dense overcast The central dense overcast, or CDO, of a tropical cyclone or strong subtropical cyclone is the large central area of thunderstorms surrounding its circulation center, caused by the formation of its eyewall. It can be round, angular, oval, or ir ...
warming. Not long afterward, the storm began to deteriorate due to cooler waters, increasing vertical wind, and dry air entrainment. The BoM downgraded the storm to a vigorous gale-force tropical low on 24 March. Around this time, Ex-Tropical Cyclone Neville assumed a more consistent course towards the southwest, and crossed over the 90th meridian east into the South-West Indian Ocean. Throughout its existence, Neville remained far from major landmasses; however, it brought near-gale-force gusts, as reported at Cocos Islands Airport, with winds reaching , causing significant structural damage at the resort on the island.


Severe Tropical Cyclone Megan

On 4 March, the BoM noted the formation of a tropical low over south of Indonesia's
Sumatra Sumatra () is one of the Sunda Islands of western Indonesia. It is the largest island that is fully within Indonesian territory, as well as the list of islands by area, sixth-largest island in the world at 482,286.55 km2 (182,812 mi. ...
or
Java Java is one of the Greater Sunda Islands in Indonesia. It is bordered by the Indian Ocean to the south and the Java Sea (a part of Pacific Ocean) to the north. With a population of 156.9 million people (including Madura) in mid 2024, proje ...
, designating it as 09U. Over the next couple of days, the BoM reported that it was developing over the western
Timor Sea The Timor Sea (, , or ) is a relatively shallow sea in the Indian Ocean bounded to the north by the island of Timor with Timor-Leste to the north, Indonesia to the northwest, Arafura Sea to the east, and to the south by Australia. The Sunda Tr ...
within the trough. Analysis from the JTWC indicated that the disturbance was in a favourable environment for development—featuring sea surface temperatures of , and low to moderate wind shear. By 15 March, the JTWC issued a TCFA on the tropical low and warned that there was a high potential for the disturbance to develop into a tropical cyclone. The tropical low moved into the Gulf of Carpentaria, whereupon it gradually organised and began to intensify. The same day, the JTWC upgraded the system to Tropical Cyclone 19S, approximately east of
Darwin, Northern Territory Darwin ( Larrakia: ') is the capital city of the Northern Territory, Australia. The city has nearly 53% of the Northern Territory's population, with 139,902 at the 2021 census. It is the smallest, wettest, and most northerly of the Australi ...
. Later the next day, the BoM reported that the tropical low had developed into a Category 1 tropical cyclone and assigned the name ''Megan''. Rapid intensification began the same day, with Megan reaching Category 2 tropical cyclone. The BoM upgraded the storm to a Category 4 severe tropical cyclone at 12:00 UTC, Operationally, the BoM classified Megan a Category 3 severe tropical cyclone with winds of , but during post-cyclone reanalysis concluded a peak wind speed of based on Synthetic-aperture radar measurements. Gradually approaching the southwestern coast of the Gulf of Carpentaria, the JTWC indicated that one-minute sustained winds had reached , equivalent to a Category 3 major hurricane on the SSHWS. Megan made landfall on the southwestern Gulf of Carpentaria coast just after 06:00 UTC on 18 March. Shortly after the landfall, the JTWC discontinued warnings on the system. After moving ashore, the cyclone turned generally southeast and tracked along the inland of
Borroloola Borroloola () is a town in the Northern Territory of Australia. It is located on the McArthur River, about upstream from the Gulf of Carpentaria. Location Borroloola lies on the traditional country of the Yanyuwa people, on the coastal plain ...
. The following day, the system was downgraded to a tropical low by the BoM as it approached the inland coast of the Gulf of Carpentaria. Ex-Tropical Cyclone Megan moved inland, tracking across the Northern Territory, before the BoM stopped monitoring the low on 21 March. A planned evacuation in Borroloola was cancelled as planes were not able to land.
Groote Eylandt Groote Eylandt ( Anindilyakwa: ''Ayangkidarrba''; meaning "island" ) is the largest island in the Gulf of Carpentaria and the fourth largest island in Australia. It was named by the explorer Abel Tasman in 1644 and is Dutch for "large island" ...
got of rain.


Tropical Low 10U

On 12 March, the BoM started to monitor a possible tropical low within the monsoon trough off the eastern Top End in the Gulf of Carpentaria, designating it as 10U. Over the next couple of days, the tropical low remained poorly organised. By 14 March, the BoM reported that a tropical low had developed within a monsoon trough east of Cape York Peninsula. Later that day, the BoM stopped monitoring the low, as it moved southeast off the coast while continuing to weaken.


Severe Tropical Cyclone Olga

On 4 April, the BoM reported that Tropical Low 11U had developed within a monsoonal trough over the south of Indonesia's
Sumba Sumba (; ), natively also spelt as Humba, Hubba, Suba, or Zuba (in Sumba languages) is an Indonesian island (part of the Lesser Sunda Archipelago group) located in the Eastern Indonesia and administratively part of the East Nusa Tenggara pro ...
. The JTWC assessed environmental conditions as being favourable for tropical cyclogenesis, with good poleward outflow and sea surface temperatures near being offset by the effects of low to moderate vertical wind shear. Convective activity began organising into a symmetrical circulation, which prompted the JTWC to issue a TCFA on the disturbance as it tracked southwestwards into a favourable environment. By 5 April, the JTWC initiated advisories on the system and classified it as Tropical Cyclone 21S, about northwest of
Learmonth, Western Australia RAAF Base Learmonth, also known as Learmonth Airport , is a joint use Royal Australian Air Force base and civil airport. It is located near the town of Exmouth on the north-west coast of Western Australia. RAAF Base Learmonth is one of the RAA ...
. Later the next day, the BoM reported that the tropical low had developed into a Category 1 tropical cyclone and assigned the name ''Olga'' as its deep convection had organised significantly along with improved curvature of its bands. The system developed a central dense overcast and a weak-developing eye. The same day, Olga intensified into a Category 3 severe tropical cyclone, while the JTWC upgraded Olga to the equivalent of a low-end Category 1 hurricane with winds of . By the following day, the storm had undergone rapid intensification to attain its peak strength with sustained winds of —equivalent to a Category 5 severe tropical cyclone—and an estimated central pressure of . The JTWC estimated one-minute sustained winds at this time to have been —equivalent to a Category 4 major hurricane. Operationally, the BoM classified Olga as a high-end Category 4 severe tropical cyclone with winds of , but during post-cyclone reanalysis concluded a peak wind speed of based on
Dvorak technique The Dvorak technique (developed between 1969 and 1984 by Vernon Dvorak) is a widely used system to estimate tropical cyclone intensity (which includes tropical depression, tropical storm, and hurricane/typhoon/intense tropical cyclone intensities ...
measurements. Upon reaching its peak, Olga entered a phase of steady weakening, whereby its eye disappeared from satellite imagery. By 8 April, the cyclone began to encounter increasing west-northwesterly shear coupled with dry air entrainment. Deep convection becoming displaced to the southeast of an increasingly-exposed LLLC. Olga was re-classified as a tropical low by the BoM at 18:00 UTC on 9 April, despite still producing gale-force winds. By the following day, the JTWC subsequently issued their final advisory on the system, as its gale-force winds soon became confined to the southern quadrant as the low became devoid of deep convection, leaving the LLLC exposed. Shortly after, the BoM stopped monitoring the low, as it moved southwest while continuing to weaken.


Tropical Cyclone Paul

On 8 April, the BoM reported that a small Tropical low had form within the monsoon trough in the northern Coral Sea near
Louisiade Archipelago The Louisiade Archipelago is a string of ten larger volcanic islands frequently fringed by coral reefs, and 90 smaller coral islands in Papua New Guinea. It is located 200 km southeast of New Guinea, stretching over more than and spread o ...
, and predesignated it as 13U. Two days later, the BoM reported that a low had formed within a trough, about east-southeast of
Port Moresby (; Tok Pisin: ''Pot Mosbi''), also referred to as Pom City or simply Moresby, is the capital and largest city of Papua New Guinea. It is one of the largest cities in the southwestern Pacific (along with Jayapura) outside of Australia and New ...
. The tropical low depicted flaring consolidated convection to the LLLC. The same day, the JTWC issued a TCFA, noting a deep convective banding wrapping into a circulation centre. Shortly after, the BoM reported that the tropical low had developed into a Category 1 tropical cyclone and assigned the name ''Paul''. The JTWC followed suit, initiated advisories on the system, and classified it as Tropical Cyclone 22S. Paul featured a ragged central dense overcast and soon became sufficiently organised, obscuring the LLCC, with the BoM upgrading the storm to a Category 2 tropical cyclone. Paul then peaked at 12:00 UTC on 11 April, with 10-minute sustained winds of , and a central barometric pressure of . Flaring deep convection became disorganised into a weakly-defined centre due to increasing westerly wind shear. The system was downgraded to a tropical low by the BoM at 00:00 UTC on 12 April. The JTWC subsequently issued their final advisory on the system, as its circulation became disorganised. The circulation of Paul had dissipated on the same day.


Tropical Low 12U

On 4 April, the BoM noted that a weak tropical low could form in the Arafura Sea, designating it as 12U. It remained traceable, and the BoM would give the developing tropical low an increased chance of developing into a tropical cyclone. By 11 April, the BoM reported that the probability of becoming a tropical cyclogenesis had decreased due to model guidance. As the system continued to move westwards, it organized further, prompting the tropical low to develop a weak circulation. By 14 April, the BoM stopped monitoring the low as it moved westwards near
East Timor Timor-Leste, also known as East Timor, officially the Democratic Republic of Timor-Leste, is a country in Southeast Asia. It comprises the eastern half of the island of Timor, the coastal exclave of Oecusse in the island's northwest, and ...
while continuing to weaken.


Tropical Low 16U

Towards the end of the Australian season, the BoM noted that a tropical low was expected to form north of the Australian Region and also gave the system a 15% chance of tropical cyclogenesis within a few days, designating it as 16U. On 4 May, the BoM reported that it was developing over the Banda Sea. At this stage, the system was located in an area of low vertical
wind shear Wind shear (; also written windshear), sometimes referred to as wind gradient, is a difference in wind speed and/or direction over a relatively short distance in the atmosphere. Atmospheric wind shear is normally described as either vertical ...
and good upper-level
divergence In vector calculus, divergence is a vector operator that operates on a vector field, producing a scalar field giving the rate that the vector field alters the volume in an infinitesimal neighborhood of each point. (In 2D this "volume" refers to ...
to the northwest of
Gove Airport Gove Airport (also known as Gove-Nhulunbuy Airport) is on the Gove Peninsula in the Northern Territory of Australia. It services the mining town of Nhulunbuy and several Aboriginal communities including Yirrkala. The airport is located sout ...
in Australia, while
atmospheric An atmosphere () is a layer of gases that envelop an astronomical object, held in place by the gravity of the object. A planet retains an atmosphere when the gravity is great and the temperature of the atmosphere is low. A stellar atmosphere ...
isolated convection persisted over the system before the BoM stopped monitoring the tropical low.


Other systems

The United States'
Joint Typhoon Warning Center The Joint Typhoon Warning Center (JTWC) is a joint United States Navy – United States Air Force command in Pearl Harbor, Hawaii. The JTWC is responsible for the issuing of tropical cyclone warnings in the North-West Pacific Ocean, South P ...
 (JTWC) reported that  Cyclone Djoungou entered the Australian region after crossing the
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. It is the border between two tropical cyclone ba ...
from the South-West Indian Ocean basin at 18:00 UTC on 19 February, located approximately to the west-southwest of
Learmonth, Western Australia RAAF Base Learmonth, also known as Learmonth Airport , is a joint use Royal Australian Air Force base and civil airport. It is located near the town of Exmouth on the north-west coast of Western Australia. RAAF Base Learmonth is one of the RAA ...
.Alt URL
/ref> Upon entering the region, the 
Météo-France Météo-France is the official French meteorological administration, also offering services to Andorra and Monaco. It has the powers of the state and can exercise them in relation to meteorology. Météo-France is in charge of observing, study ...
(MFR) issued its last advisory on Djoungou as it transitioned into a post-tropical depression. The system had commenced upon entering the region due to the effects of hostile
vertical wind shear Wind shear (; also written windshear), sometimes referred to as wind gradient, is a difference in wind speed and/or direction over a relatively short distance in the atmosphere. Atmospheric wind shear is normally described as either vertical o ...
of . At this time, the JTWC assessed the system as a
subtropical cyclone A subtropical cyclone is a weather system that has some characteristics of both tropical cyclone, tropical and extratropical cyclones. As early as the 1950s, meteorologists were uncertain whether they should be characterized as Tropical cyclone ...
, with maximum one-minute sustained winds of . The JTWC subsequently issued its final advisory on Djoungou, as its circulation became fully exposed. The Australian
Bureau of Meteorology The Bureau of Meteorology (BOM or BoM) is an executive agency of the Government of Australia, Australian Government that is responsible for providing Weather forecasting, weather forecasts and Meteorology, meteorological services to Australia a ...
(BoM) indicated that a potential tropical low was expected to form north of 
Vanuatu Vanuatu ( or ; ), officially the Republic of Vanuatu (; ), is an island country in Melanesia located in the South Pacific Ocean. The archipelago, which is of volcanic origin, is east of northern Australia, northeast of New Caledonia, east o ...
in a few days on 12 April, designating it as 14U. The potential tropical low was assessed as having a low probability of developing into a tropical cyclogenesis. Once formed, the low may contribute to a strengthening of the  southeasterly winds to the south that will extend towards the southern Queensland coast, until they determine that it will not develop into a tropical cyclogenesis on 18 April. On 15 April, the BoM started highlighting the chances of the development of a tropical low offshore the Top End and also gave the system a 30% chance of tropical cyclogenesis within a few days, designating it as 15U. On 19 April, the BoM also reported that a potential tropical low was starting to form in the eastern Arafura Sea. Shortly after, the BoM stopped monitoring the potential low, as its probability of becoming a tropical cyclogenesis had decreased.


Storm names


Bureau of Meteorology

The Australian Bureau of Meteorology (TCWC Melbourne) monitors all tropical cyclones that form within the Australian region, including any within the areas of responsibility of TCWC
Jakarta Jakarta (; , Betawi language, Betawi: ''Jakartè''), officially the Special Capital Region of Jakarta (; ''DKI Jakarta'') and formerly known as Batavia, Dutch East Indies, Batavia until 1949, is the capital and largest city of Indonesia and ...
or TCWC
Port Moresby (; Tok Pisin: ''Pot Mosbi''), also referred to as Pom City or simply Moresby, is the capital and largest city of Papua New Guinea. It is one of the largest cities in the southwestern Pacific (along with Jayapura) outside of Australia and New ...
. Should a tropical low intensify into a tropical cyclone within the BoM's area of responsibility, it will be assigned the next name from the following naming list. The names ''Lincoln'' and ''Megan'' were used for the first (and only time, in case of Megan) time this season, after replacing ''
Laurence Laurence is in modern use as an English masculine and a French feminine given name. The modern English masculine name is a variant of Lawrence and originates from a French form of the Latin ''Laurentius'', a name meaning "man from Laurentum" ...
'' and ''Magda'' respectively, from the 2009–10 season. The names that will be used for the 2023–24 season are listed below:


Retirement

Later in 2024, the World Meteorological Organisations RA V Tropical Cyclone Committee retired the names ''Jasper'', ''Kirrily'' and ''Megan'', replacing them with the names ''Julian'', ''Kima'' and ''Merryn'' respectively, due to the damage caused by the systems in Western Australia and the South Pacific. http://www.bom.gov.au/cyclone/tropical-cyclone-knowledge-centre/understanding/tc-names/


TCWC Jakarta

TCWC Jakarta monitors all tropical cyclones active from the Equator to 11S and from 90E to 145E. Should a tropical depression intensify into a tropical cyclone within TCWC Jakarta's Area of Responsibility, it will be assigned the next name from the following list.


TCWC Port Moresby

Tropical cyclones that develop north of 11°S between 151°E and 160°E are assigned names by the Tropical Cyclone Warning Centre in
Port Moresby (; Tok Pisin: ''Pot Mosbi''), also referred to as Pom City or simply Moresby, is the capital and largest city of Papua New Guinea. It is one of the largest cities in the southwestern Pacific (along with Jayapura) outside of Australia and New ...
,
Papua New Guinea Papua New Guinea, officially the Independent State of Papua New Guinea, is an island country in Oceania that comprises the eastern half of the island of New Guinea and offshore islands in Melanesia, a region of the southwestern Pacific Ocean n ...
. Tropical cyclone formation in this area is extremely rare, with no cyclones being named in it since
2007 2007 was designated as the International Heliophysical Year and the International Polar Year. Events January * January 1 **Bulgaria and Romania 2007 enlargement of the European Union, join the European Union, while Slovenia joins the Eur ...
. As names are assigned in a random order, the whole list is shown below:


Season effects

This table lists all of the
tropical cyclone A tropical cyclone is a rapidly rotating storm system with a low-pressure area, a closed low-level atmospheric circulation, strong winds, and a spiral arrangement of thunderstorms that produce heavy rain and squalls. Depending on its locat ...
s and
subtropical cyclone A subtropical cyclone is a weather system that has some characteristics of both tropical cyclone, tropical and extratropical cyclones. As early as the 1950s, meteorologists were uncertain whether they should be characterized as Tropical cyclone ...
s that were monitored during the 2023–2024 Australian region cyclone season. Information on their intensity, duration, name, areas affected, primarily comes from TCWC Melbourne. Death and damage reports come from either press reports or the relevant national disaster management agency while the damage totals are given in 2023 or 2024 USD.


See also

*
Weather of 2023 The following is a list of weather events that occurred on Earth in the year 2023. The year saw a transition from La Niña to El Niño, with record high global average surface temperatures. There were several natural disasters around the world f ...
and
2024 The year saw the list of ongoing armed conflicts, continuation of major armed conflicts, including the Russian invasion of Ukraine, the Myanmar civil war (2021–present), Myanmar civil war, the Sudanese civil war (2023–present), Sudane ...
*
List of Southern Hemisphere tropical cyclone seasons The tropical cyclone seasons that occur in the Southern Hemisphere are: *South-West Indian Ocean tropical cyclone **Current – South-West Indian Ocean cyclone season *Australian region tropical cyclone **Current – Australian region cyclon ...
*Tropical cyclones in
2023 Catastrophic natural disasters in 2023 included the Lists of 21st-century earthquakes, 5th-deadliest earthquake of the 21st century 2023 Turkey–Syria earthquakes, striking Turkey and Syria, leaving up to 62,000 people dead; Cyclone Freddy ...
,
2024 The year saw the list of ongoing armed conflicts, continuation of major armed conflicts, including the Russian invasion of Ukraine, the Myanmar civil war (2021–present), Myanmar civil war, the Sudanese civil war (2023–present), Sudane ...
*Atlantic hurricane seasons:
2023 Catastrophic natural disasters in 2023 included the Lists of 21st-century earthquakes, 5th-deadliest earthquake of the 21st century 2023 Turkey–Syria earthquakes, striking Turkey and Syria, leaving up to 62,000 people dead; Cyclone Freddy ...
,
2024 The year saw the list of ongoing armed conflicts, continuation of major armed conflicts, including the Russian invasion of Ukraine, the Myanmar civil war (2021–present), Myanmar civil war, the Sudanese civil war (2023–present), Sudane ...
*Pacific hurricane seasons:
2023 Catastrophic natural disasters in 2023 included the Lists of 21st-century earthquakes, 5th-deadliest earthquake of the 21st century 2023 Turkey–Syria earthquakes, striking Turkey and Syria, leaving up to 62,000 people dead; Cyclone Freddy ...
,
2024 The year saw the list of ongoing armed conflicts, continuation of major armed conflicts, including the Russian invasion of Ukraine, the Myanmar civil war (2021–present), Myanmar civil war, the Sudanese civil war (2023–present), Sudane ...
*Pacific typhoon seasons:
2023 Catastrophic natural disasters in 2023 included the Lists of 21st-century earthquakes, 5th-deadliest earthquake of the 21st century 2023 Turkey–Syria earthquakes, striking Turkey and Syria, leaving up to 62,000 people dead; Cyclone Freddy ...
,
2024 The year saw the list of ongoing armed conflicts, continuation of major armed conflicts, including the Russian invasion of Ukraine, the Myanmar civil war (2021–present), Myanmar civil war, the Sudanese civil war (2023–present), Sudane ...
*North Indian Ocean cyclone seasons:
2023 Catastrophic natural disasters in 2023 included the Lists of 21st-century earthquakes, 5th-deadliest earthquake of the 21st century 2023 Turkey–Syria earthquakes, striking Turkey and Syria, leaving up to 62,000 people dead; Cyclone Freddy ...
,
2024 The year saw the list of ongoing armed conflicts, continuation of major armed conflicts, including the Russian invasion of Ukraine, the Myanmar civil war (2021–present), Myanmar civil war, the Sudanese civil war (2023–present), Sudane ...
*
2023–24 South-West Indian Ocean cyclone season The 2023–24 South-West Indian Ocean cyclone season was an above-average season, including ten named storms (including an unnamed tropical storm), six tropical cyclones and two intense tropical cyclones. Despite its moderate activity, it was the ...
*
2023–24 South Pacific cyclone season The 2023–24 South Pacific cyclone season was a below-average season within the South Pacific Ocean to the east of 160°E. The season officially started on 1 November 2023 and ended on 30 April 2024, however a tropical cyclone could form betwee ...


References


External links


Australian Bureau of Meteorology



TCWC Jakarta

Papua New Guinea National Weather Service
{{DEFAULTSORT:2023-24 Australian region cyclone season 2023 meteorology 2024 meteorology Tropical cyclones in 2023 Tropical cyclones in 2024 2023-24