As early as 14 January, long-range ensemble forecast guidance from the Global Forecast System and the European Centre for Medium-Range Weather Forecasts began to suggest a formation of a tropical cyclone to the northeast of the Mascarene Islands.[2] At 07:30 UTC on 20 January, the Joint Typhoon Warning Center reported a formation of an area of convection, which they designated as Invest 93S, approximately 378 nmi (700 km; 435 mi) from Mauritius, with the agency giving a low chance for potential tropical cyclogenesis within the next 24 hours.[3] At midday, the Météo-France La Réunion (MFR) noted that a closed circulation was now present to the north-northwest of Saint-Brandon. The formation of the disturbance was caused by the surge of monsoonal flow.[4] By the evening, the JTWC upgraded the system to a medium chance for potential tropical cyclogenesis, after noticing its obscure low-level circulation (LLC).[5] Early the next day, at 02:00 UTC, the JTWC issued its Tropical Cyclone Formation Alert (TCFA) for Invest 93S and also upgraded the system to a high chance for potential tropical cyclogenesis, as the agency noted its consolidation of a well-defined low-level center.[6] Later at 12:00 UTC, the MFR declared the tropical low pressure system as a zone of disturbed weather, becoming the first system of the season. The department noted the elongated circulation, which was a little more compact than yesterday, but still rather poorly organized.[7] Twelve hours later, the MFR upgraded it to tropical disturbance status, as they found that the system's cloud pattern had improved. Furthermore, its center had become well-defined but was still overall ill-defined and elongated.[8] The disturbance slowly consolidated into a defined convective structure while also developing distinct curved rainbands, which prompted the MFR to upgrade it to a tropical depression by 06:00 UTC on 22 January.[9]
Between 08:00 UTC and 09:00 UTC, the system's center crossed between Toamasina and Île Sainte-Marie as a tropical depression, with the MFR re-classifying the system as an overland depression.[10][11] Because of the mountainous terrain of Madagascar, the system weakened a bit but still managed to preserve its organized convection and its low-level center.[11] At 06:00 UTC the next day, the MFR re-classified it again as a tropical disturbance after entering the Mozambique Channel.[12] Six hours later, it re-intensified into a tropical depression, as it gradually improved its convective structure and cooling of its convective bands. Its low-level clouds had developed a distinct curved pattern near the center. This occurred after entering the Mozambique Channel, where more conductive environmental conditions were available along with good convergence of monsoonal flow.[13] At 15:00 UTC, the JTWC declared the system a tropical cyclone and designated it 07S.[14] The MFR later upgraded it to a moderate tropical storm and named it Ana, becoming the first named storm of the season.[15] Ana maintained its intensity until at 08:00 UTC the same day, when it made landfall near south of Angoche, Mozambique.[16][17] The system later moved westwards as an overland depression, crossing across southern Malawi and northern Zimbabwe, and by midday of 25 January, it became a remnant low over the adjoining areas of Zimbabwe and Zambia.[18] The remnant later moved towards Angola and was last noted on 30 January around Namibia and Angola.[19]
Impact
The storm caused dozens of casualties in Madagascar, Malawi and Mozambique, while causing severe damage to infrastructure in Malawi. It was feared that Cyclone Batsirai – which made landfall in Madagascar on 6 February – would hinder relief work.[20]
Before becoming a moderate tropical storm, Ana made landfall as a tropical depression in Madagascar, causing heavy rainfall which led to deadly landslides and floods; it caused 58 fatalities in the country.[21] An estimated 55,000 people had become homeless and 130,000 were forced to flee to temporary habitation centres.[22][23]
Malawi
The region around Mulanje in Southern Malawi was particularly affected.[24] 37 were reported dead with another 22 remaining missing as of 31 January. 158 people were injured.[25] Most of the country lost electricity, and 200,000 had to leave their homes.[26][22] 109,359 people were forced to reside in emergency camps.[25] Floods damaged the Kapichira Hydroelectric Power Station, which provides 30% of the country's electricity. The nationwide electricity supply remained intermittent days after the storm passed.[25][23][27]
Mozambique
The storm also killed 20 people in Mozambique.[28] 10,000 houses in Mozambique were destroyed as a result of the storm. An additional 20,000 were affected by the cyclone.[29]
