1999–2000 South-West Indian Ocean cyclone season
The 1999–2000 South-West Indian Ocean tropical cyclone season was the first on record in which two storms – Leon–Eline and Hudah – struck Mozambique at tropical cyclone intensity, or with maximum sustained winds of at least 120 km/h (75 mph). The most notable storm of the season was Eline, which was the longest-lasting storm on record in the basin. It lasted for 29 days while traversing the southern Indian Ocean, making the strongest landfall in decades along eastern Madagascar in late February. The storm was the first in a series of three storms that struck the country in early 2000, along with Gloria in March and Hudah in April. Collectively, the three storms killed at least 316 people. The season started on November 1, 1999, and ended for most of the basin on April 30, 2000; for Mauritius and the Seychelles, the season continued until May 15. These dates conventionally delimit the period of each year when most tropical cyclones form in the basin;
1998 North Indian Ocean cyclone season
The first cyclone in the region developed as a tropical disturbance on May 13 over the southern Bay of Bengal to the southeast of Sri Lanka. With little development, the disturbance initially traveled towards the north-northeast before turning west. On May 16, the system slowed down near the southeastern coast of India and began to turn towards the northeast once more. At 0700 UTC on May 17, the Joint Typhoon Warning Center (JTWC) issued a Tropical Cyclone Formation Alert (TCFA). Shortly after, the India Meteorological Department (IMD) declared that the disturbance developed into Depression BOB 01. A second TCFA was issued later that day as a new circulation associated with the system developed further towards the northeast. At 0600 UTC on May 18, the first advisory on Tropical Cyclone 01B was issued by the JTWC. At the time of the advisory, winds were estimated at 55 km/h (35 mph). The IMD also upgraded BOB 01 to a deep depression at this time.