Cyclone Gafilo
Very Intense Tropical Cyclone Gafilo was both the most intense tropical cyclone ever recorded in the South-West Indian Ocean and the most intense tropical cyclone worldwide in 2004. Being unusually large and intense, Gafilo was the deadliest and most destructive cyclone of the 2003–04 South-West Indian Ocean cyclone season. According to the EM-DAT International Disaster Database, Gafilo killed at least 363 people. Gafilo also caused about $250 million damages in Madagascar, which makes it one of most devastating storms to hit the country on reliable record.
Forming south of Diego Garcia, it intensified into a moderate tropical storm on 3 March. One day later, Gafilo became a tropical cyclone, and it ultimately intensified into a very intense tropical cyclone on 6 March, prior to making landfall over Madagascar early on the next day. After crossing the island, Gafilo emerged into the Mozambique Channel and made landfall over Madagascar again on 9 March. After a three-day loop overland, the system arrived at the Indian Ocean on 13 March, and it transitioned into a subtropical depression on 14 March. Gafilo then became extratropical on the next day and weakened, before dissipating on 18 March.
Meteorological history
A disturbance formed south of Diego Garcia on 29 February, and Météo-France La Réunion upgraded the identified system within the monsoon trough to a tropical disturbance on the next day. On 2 March, although the centre was exposed due to moderate easterly vertical wind shear, the Joint Typhoon Warning Center issued a Tropical Cyclone Formation Alert on the system which was situated north of a subtropical ridge, based on improved organisation of deep convection and moderate poleward outflow. However, its temporary acceleration on that day lessened vertical wind shear. As the centre became under organised deep convection on 3 March, the system intensified into a tropical depression, then a moderate tropical storm named Gafilo by the Sub-regional Tropical Cyclone Advisory Centre in Mauritius, shortly before MFR even upgraded Gafilo to a severe tropical storm later. When the system slowed and tracked west-northwestwards along the northern periphery of a building subtropical ridge, it reached category 1 strength on the Saffir–Simpson hurricane wind scale late on 3 March.The complete pattern of the cyclone from 4 to 8 March as it moved through the south western Indian Ocean has been recorded by the TRMM through its satellite imagery. TRMM is a joint mission between NASA and the Japanese space agency JAXA.
Although dry air significantly reduced deep convection on 4 March, MFR upgraded Gafilo to a tropical cyclone due to a banding eye, when the system began to expand its clockwise circulation and track west-southwestwards. By dual outflow channels, Gafilo underwent rapid deepening and reached category 4 strength on the Saffir–Simpson hurricane wind scale on 5 March, as MFR also upgraded Gafilo to an intense tropical cyclone late on the same day. On 6 March, besides warm sea surface temperature above 29 °C, the atypical third outflow channel from the west made conditions for the cyclone more favourable. Therefore, MFR upgraded Gafilo to a very intense tropical cyclone with a very well-defined circular and warm diameter eye at 06Z, when it also reached category 5 strength on the Saffir–Simpson hurricane wind scale. At 12Z, Gafilo attained its peak intensity by the ten-minute maximum sustained winds reaching 125 knots and the atmospheric pressure decreasing to, although microwave imagery showed that the eyewall replacement cycle had begun.
Shortly after slightly weakening due to land interaction, Gafilo made landfall in the vicinity of Antalaha, Madagascar early on 7 March. Unlike other storms, the overland depression just weakened gradually, because of its unusually large circulation making the outer part still at sea. On that day, Gafilo tracked more southwestwards along the northwestern periphery of a subtropical ridge located to the southeast. Before noon on 8 March, Gafilo arrived at the Mozambique Channel as a moderate tropical storm whose strongest winds were located in the northern sector. On 9 March, Gafilo became almost stationary and then tracked southeastwards along the western periphery of a subtropical ridge located to the east. MFR upgraded the system to a severe tropical storm supported by observed data from Malagasy stations at noon; however, JTWC analysed that the storm became below category 1 strength on the Saffir–Simpson hurricane wind scale at the same time in their best track data.
Late on 9 March, Gafilo made landfall north of Morombe, Madagascar, and the system started to make a three-day clockwise loop over the south part of Madagascar. For the system further weakened after landfall, JTWC analysed that Gafilo dissipated overland late on 11 March, as well as MFR issued a final warning on the overland depression which began to track southeastwards early on 12 March. Surprisingly, MFR began to issue warnings again on the completely disorganised system at noon on 12 March, as the residual centre was expected to go back overseas. Late on the same day, JTWC issued a Tropical Cyclone Formation Alert on the overland remnants, because of improved deep convection over the low-level circulation centre, poleward outflow and weak vertical wind shear.
Early on 13 March, Gafilo arrived at the Indian Ocean as a tropical disturbance; JTWC cancelled a Tropical Cyclone Formation Alert on the system because of the less organised low-level circulation centre and moderate vertical wind shear. Gafilo transferred into a subtropical depression south of La Réunion on 14 March, when the deep convective activity was intensifying with better organisation of a small cluster above the low-level circulation centre due to good upper-level divergence and a warm sea surface temperature of 26 °C to 29 °C. After attaining minor peak intensity in its subtropical period late on 14 March, Gafilo began to track eastward and transitioned into an extratropical depression on 15 March. Owing to a building subtropical ridge located to the southwest, the extratropical depression slowed and turned northwestwards on 16 March. After slowly weakening, the system completely dissipated on 18 March.
Impact
Madagascar
Gafilo caused strong winds and torrential rainfall over Madagascar. A half-day after the first landfall, hurricane-force winds were still observed near Mahajanga late on 7 March. When Gafilo was reorganising in the Mozambique Channel, of precipitation was recorded at Maintirano on 9 March, as well as was recorded at Tôlanaro on the same day. During its three-day loop overland, Gafilo brought at Morondava on 11 March.As Elita had already struck Madagascar one month ago, damage from Gafilo created extreme devastation in the country. The National Rescue Council in Antananarivo reported 237 dead, 181 missing, 879 injured, and 304,000 homeless. More than 20,000 homes were destroyed, as well as 413 public buildings and 3,400 schools were damaged, including 1,400 schools completely destroyed. The United Nations estimated that there were 700,000 disaster-stricken people, 280,000 of which needed urgent assistance.
Despite being located north of Gafilo's centre, the wreck of the ferry 'Samson' still happened on the night of 7 March, offshore the northwestern port of Mahajanga. A narrow but strong band of Gafilo caused very rough conditions at sea, causing the ferry to experience engine failure and capsize immediately after. While the number of fatalities remains undetermined, 120 people were officially on board, and only three people reached shore, surviving the shipwreck. The ferry had been heading to Madagascar from the Comoros Islands at the time of its sinking.
In Antalaha, food prices shot up by 35%, and the harbour was badly damaged and non-operational. Roads and bridges connecting the city to outlying villages were inaccessible, and electricity, water and telephone lines were cut. Overall in Madagascar, the main damage caused by Gafilo was the subsequent flooding of vast areas in the north, northwest and southwest; Where extensive, the flooding caused serious damage to vanilla, rice and banana crops. In many places, the crops were expected to be totally lost.
Moreover, shrimp harvesting also suffered. Some of the affected areas coincided with those affected by Elita, and stocks and resources were already depleted in many areas. In the absence of immediate response, an increase in water-borne diseases such as malaria and diarrhoea could have occurred immediately, while outbreaks of cholera were expected to be seen within the coming 6–8 weeks.