Costa thereafter weakened rapidly and moved erratically toward the southwest. By January 15, it deteriorated into a minimal tropical storm, and meandered for several days. On January 19, Costa dissipated within the flow of the westerlies. When Costa formed, it passed near Agaléga, producing wind gusts of . The storm approached St. Brandon twice; on its first passage, Costa produced gusts of during a strong rainband. Later, the storm dropped of rainfall on Rodrigues while producing gusts of . The monsoon was active in early January across the Indian Ocean, spawning what would eventually become Tropical Cyclone Delifina. On January 7, the JTWC classified the system as Tropical Cyclone 04S to the east-southeast Tropical Storm Costa. However, the MFR did not classify it initially due to lack of data. The system had a curved area of convection, and organized enough for MFR to designate it Tropical Storm Delifina on January 10. On the same day, the JTWC upgraded the storm to the equivalent of a minimal hurricane. The storm moved generally southward, after an initial westward movement. Delifina gradually intensified, becoming a tropical cyclone on January 13. By that time, the storm had an eye in the center of deep organized convection. The MFR estimated peak winds of 135 km/h (85 mph), while the JTWC estimated 1 minute winds of 205 km/h (125 mph). Subsequently, Delifina weakened as it progressed southward. After turning to the southeast, the deteriorating storm turned sharply northwestward between two ridges. Delifina turned back to the east and dissipated on January 19 at nearly the same longitude where it formed. Satellite imagery indicated that a tropical disturbance formed on January 29 to the southwest of Diego Garcia. It moved westward and slowly organized, becoming a moderate tropical storm on January 31. On the same day, the JTWC classified the storm as Tropical Cyclone 13S, and the Mauritius Meteorological Service named it Erinesta. Its track shifted to a slow west-southwest trajectory while intensifying. The JTWC upgraded the storm to the equivalent of a minimal hurricane on February 1, and the MFR upgraded Erinesta to tropical cyclone status on the next day. On February 4, the cyclone attained peak winds, becoming one of the strongest storms in the basin in several decades.