The remnant low of Freddy began to acquire tropical characteristics after re-emerging into the channel. Soon after, Freddy intensified, becoming a tropical cyclone. Then, Freddy made its final landfall in
Quelimane,
Zambezia Province, Mozambique, Freddy gradually deteriorated and last noted on 14 March. Catastrophic flooding and extensive wind damage ensued, resulting in 1,434 fatalities across Madagascar, Mozambique, Malawi, Mauritius, and Zimbabwe, making it the third-deadliest tropical cyclone recorded in the Southern Hemisphere, only behind
2019's
Cyclone Idai and the
1973 Flores cyclone. Total damages are estimated to reach $655 million, making it the second-costliest cyclone in the south-west Indian Ocean after Idai in 2019.
Origin and intensification
The presence of the
Madden–Julian Oscillation and an equatorial
Rossby wave in the Australian region contributed to the formation of tropical low over the north of Western Australia.[3] A tropical low was originally identified south of
Bali, Indonesia early on 5 February.[4] Originally, the circulation was poorly defined and elongated, but in the evening and overnight, persistent convection occurred and began to show signs of improvement in the organization.[4][5] During 6 February, the
Joint Typhoon Warning Center (JTWC)[nb 1] issued a
Tropical Cyclone Formation Alert (TCFA) on the system.[7] By 09:00 UTC, the JTWC initiated advisories on the system and classified it as Tropical Cyclone 11S.[8]
During a period of rapid development while moving slowly south-southwest, the Australian
Bureau of Meteorology (BoM)[nb 2] stated that the tropical low had strengthened into a Category 1 tropical cyclone on the Australian tropical cyclone intensity scale and was given the name Freddy.[4][10][11] Later that next day, feeder bands were covering its very broad
central dense overcast (CDO), prompting the JTWC to upgrade the system to a Category 1-equivalent cyclone.[12] The BoM subsequently followed suit and upgraded Freddy into a Category 2 tropical cyclone.[13] Freddy attained Category 3 cyclone.[14] Freddy began showing an eye feature seen in
microwave imaging, with Freddy later becoming a Category 2-equivalent cyclone.[15]
Freddy weakened slightly due to CDO and a persistent area of cold cloud tops.[16] Weakening occurred as the JTWC assessed that Freddy's winds bottomed out at 150 km/h (90 mph).[17] Freddy weakened back into a tropical storm, and the BoM estimated winds of 100 km/h (65 mph), the weakening resulting from easterly wind shear.[18][19] Continuing to rapidly intensify, Freddy became a Category 3-equivalent cyclone around 15:00 UTC on 11 February.[20] Freddy had further intensified to a Category 4 severe tropical cyclone due to the presence of a well-defined eye surrounded by deep convection.[21] Freddy intensified into a Category 4-equivalent cyclone with a symmetric CDO.[22] According to the JTWC, Freddy gradually became disorganized, with its eye no longer well-defined, and Freddy fell to 185 km/h (115 mph) winds.[23]
The BoM also reported that Freddy's winds weakened to 155 km/h (100 mph).[24] Despite easterly vertical wind shear, Freddy maintained a symmetric convective core.[25] The cyclone's ragged and cloud filled eye appeared on satellite imagery.[26] At 12:00 UTC on 14 February, Freddy crossed
90° E into the South-West Indian Ocean basin, and was immediately classified as a tropical cyclone by
Météo-France (MFR)[nb 3][28][29] The MFR upgraded the system to an intense tropical cyclone.[30] Freddy exhibited highly symmetrical and
annular characteristics around 03:00 UTC on 15 February.[31] Later the next day, the JTWC also assessed Freddy as having 1-minute maximum sustained winds of 270 km/h (165 mph), making the storm a Category 5-equivalent tropical cyclone,[32][33] as the cyclone sustained a symmetric ring around deep convection.[34] During 18 February, Freddy began to rapidly deteriorate as a sudden spike in mid-level shear began impacting the storm.[35]
Strengthening and weakening
The cyclone briefly weakened to 1-minute sustained winds of 205 km/h (125 mph) before restrengthening once again.[36] Later that next day, Freddy was upgraded to a very intense tropical cyclone.[37] Shortly afterward, Freddy's cloud pattern slightly deteriorated, causing the cyclone to weaken to an intense tropical cyclone by 00:00 UTC on 20 February.[38] Freddy passed north of
Mauritius and
Réunion[39] and weakened to a tropical cyclone on 21 February.[40] At about 7 p.m. local time that day, the cyclone made its first
landfall near
Mananjary,
Madagascar.[41] After landfall, Freddy was re-classified as an overland depression, with sustained winds of 110 km/h (70 mph).[42] The JTWC also reported that Freddy substantially weakened as it traversed the mountainous terrain of Madagascar, and was downgraded to 130 km/h (80 mph).[43] During 22 February, Freddy significantly improved in organization as it moved southwestward across the
Mozambique Channel.[44] Freddy re-strengthened into a zone of disturbed weather.[44][45] Freddy had re-developed under the deep convection in the northern semicircle of the circulation.[46] Freddy re-strengthened into a moderate tropical storm after the convection began to rapidly increase.[47] The system passed to the north of
Europa Island.[48]
Freddy re-strengthened further, marking its intensification into a severe tropical storm.[49] Freddy continued to organize with convective bands wrapping into the center.[50] Six hours later, the cloud pattern deteriorated, as it approached the coast of
Mozambique.[51] By 12:00 UTC on 24 February, the MFR reported that Freddy had made its second landfall in Mozambique south of
Vilankulos, with 10-sustained winds of 85 km/h (50 mph).[52] Shortly after the landfall, the JTWC discontinued warnings about the system.[53] Freddy rapidly weakened as it moved westward and further inland, weakening to an overland depression by 18:00 UTC that day.[54] The MFR determined that Freddy's convective activity was located in the southeast semicircle.[55] Although the MFR stopped issuing advisories on 25 February, they were still monitoring and predicted that the remnant low would likely re-develop into a tropical system.[56][57]
The structural evolution of Cyclone Freddy from a landfall to moving over Mozambique
21 February: Freddy continuing to inch closer to the east coast of Madagascar
22 February: Freddy substantially weakened as it traversed the mountainous terrain of Madagascar.
23 February: Freddy regenerating over the Mozambique Channel.
24 February: Freddy nearing Mozambique
25 February: Freddy moving over Mozambique.
Regeneration and demise
During 1 March, Freddy re-emerged into the Mozambique Channel, the JTWC resumed monitoring and stated the system had the potential to re-develop.[58] Environmental conditions were assessed as being marginally conducive for tropical cyclogenesis, with low vertical
wind shear and moderate equatorial outflow.[58] During 2 March, Freddy observed an increase in deep convection in the eastern semicircle, prompting the MFR to classify the storm as a tropical disturbance again.[59] Microwave imagery revealed that Freddy convection was gradually wrapping around the southern periphery of the circulation.[60] Later that next day, Freddy was downgraded to zone of disturbed weather status by the MFR.[61] Multispectral animated satellite imagery partially revealed an exposed
low-level circulation center (LLCC) with deep convection persisting along the eastern periphery of the LLCC.[62] As a result, the JTWC re-issued a TCFA by 21:00 UTC that day.[62] Freddy showed signs of intensification as it approached the system's estimated center, the MFR upgraded the system to a tropical depression.[63] Freddy strengthened into a moderate tropical storm as the ASCAT-C pass featured below gale-force winds on its southern quadrant.[64] Six hours later, Freddy gained tropical storm strength yet again under the influence of a persistent area of convection.[65] The convection continued to decrease, and Freddy was better organized through the LLCC.[66] Freddy gradually improved its convection with improvements in further consolidation.[67] By 18:00 UTC on 5 March, Freddy strengthened into a severe tropical storm as it accelerated eastward toward the coast of Madagascar.[68]
The convection wrapped around the system's LLCC and the system gradually consolidated.[69] Freddy began to show an ill-defined eye that was visible on satellite imagery.[70] During 7 March, Freddy had become a tropical cyclone with sustained winds of 130 km/h (80 mph), while the JTWC estimated that its 1-minute sustained winds reached 155 km/h (100 mph).[71][72] Six hours later, Freddy continued to interact with a mid-troposphere shear.[73] Freddy fell to severe tropical storm status later that next day.[74] The cyclone then rapidly weakened as a result of the presence of higher wind shear as well as dry air intrusion.[75] Later, the storm weakened to 110 km/h (70 mph).[75] Despite the shear, convection intensified near the center as banding features improved.[76][77] The
Dvorak analysis indicated that Freddy strengthened to 120 km/h (75 mph).[78] The cyclone had a well-defined eye within the storm's compact and symmetrical CDO.[79][80] During 11 March, Freddy made its third landfall on
Quelimane,
Zambezia Province, Mozambique, with sustained winds of 150 km/h (90 mph).[81][82] The JTWC subsequently issued a final warning on the system three hours later.[83] As the cyclone's eye disappeared from satellite imagery, Freddy weakened into a severe tropical storm.[84] Six hours later, Freddy's cloud pattern deteriorated, with the storm weakening back into a moderate tropical storm.[85] Freddy weakened to an overland depression with sustained winds of around 55 km/h (35 mph).[86] At 12:00 UTC on 14 March, the MFR ceased monitoring it as a tropical cyclone.[87]
The structural evolution of Cyclone Freddy from a regeneration into a tropical cyclone
5 March: Freddy began to acquire tropical characteristics after re-emerging into the channel.
6 March: Freddy meandering off the west coast of Madagascar.
7 March: Freddy intensifying off the coast of Madagascar.
11 March: Freddy nearly stationary while off the coast of Mozambique.
12 March: Freddy weakening after its second landfall in Mozambique while delivering flooding rains.
Records
Cyclone Freddy holds the record for the longest-lasting tropical cyclone worldwide in recorded history,[2][88] pending a formal investigation to be conducted by the
World Meteorological Organization (WMO), in order to determine whether Freddy truly tied or surpassed John's record.[89] Freddy also holds the record for the all-time highest
accumulated cyclone energy of a
tropical cyclone worldwide, with an ACE of 87.01, breaking the former record of 85.26, set by
Ioke in 2006.[1] Additionally, Freddy was the first tropical cyclone to undergo seven separate rounds of
rapid intensification.[1] No other tropical cyclone in the
Southern Hemisphere is known to have rapidly intensified more than three times.[90] Only three other storms, all in the
Northern Hemisphere, underwent four periods of rapid intensification, namely
Norman in 2018,
Emily in 2005, and Hurricane |John in 1994.[2] Freddy was one of only four systems—the others being cyclones
Litanne in
1994 and
Leon–Eline and
Hudah in
2000—to travel the entirety of the southern Indian Ocean.[91]
Hurricane John (1994) – The second longest-lasting and the farthest-traveling tropical cyclone ever observed
Cyclones Katrina and Victor–Cindy (1998) – An extremely long-lived tropical cyclone in the South Pacific that eventually regenerated into another cyclone in the Indian Ocean
Hurricanes Dora
in 1999 and
in 2023 – Both tracked across all three north Pacific basins
^The
Joint Typhoon Warning Center is a joint United States Navy – United States Air Force task force that issues tropical cyclone warnings for the Indian Ocean and other regions.[6]
^Clegg, Pete; Craig, Earl-Spurr; Paterson, Linda (17 June 2022).
Severe Tropical Cyclone Freddy(PDF) (Report). Tropical Cyclone Report. Perth, Western Australia: Bureau of Meteorology. Retrieved 19 July 2023.
^Frequently Asked Questions (Report). Joint Typhoon Warning Center. 13 August 2012.
Archived from the original on 4 October 2013. Retrieved 22 September 2012.