In late April, an area of convection persisted southwest of Diego Garcia in the southern Indian Ocean.
The system had a low-level circulation and pulsating thunderstorm activity.
Located in an area of weak to moderate wind shear, the convection gradually organized while developing outflow.
On May 2, a secondary area of convection, also with an accompanying circulation, formed to the northwest, and also showed signs of development.
That day, the original disturbance organized enough for Météo-France (MFR) to designate it Tropical Disturbance 16 at 1200 UTC.
The Joint Typhoon Warning Center (JTWC) issued tropical cyclone formation alerts for both systems within a 14‑hour period, and upgraded the original system to Tropical Cyclone 18S on May 3 about 980 km (610 mi) northeast of Mauritius.
Due to the disturbance to the northwest, as well as a building ridge to the northeast, the system continued to the southwest.
On May 4, MFR upgraded the disturbance to a tropical depression and later Tropical Storm Manou.

According to the JTWC, the storm quickly reached 1-minute sustained winds of 85 km/h (50 mph).
The secondary disturbance to the west weakened while approaching the storm.
Manou also weakened due to ongoing shear, and the windspeeds dropped as the circulation became exposed from the convection.
On May 6, the storm re-intensified and the thunderstorms redeveloped while passing north of Mauritius and Réunion.
On May 8 while approaching Madagascar, Manou developed an eye, and as a result, MFR upgraded it to tropical cyclone status, with 10-minute winds of 120 km/h (75 mph).
The JTWC also upgraded the storm to the equivalent of a minimal hurricane.
After becoming a tropical cyclone, Manou intensified further, although its forward motion slowed significantly.
MFR estimated peak 10-minute winds of 155 km/h (95 mph) on May 8, and JTWC estimated peak 1-minute winds of 140 km/h (85 mph), with gusts to 165 km/h (105 mph).
This made Manou a rare May tropical cyclone in the basin; only four other storms that formed in the south-west Indian Ocean in May reached winds of over 140 km/h (85 mph) since satellite coverage began, most recently Cyclone Kesiny in the previous year.

While maintaining its peak intensity and an eye 44 km (28 mi) in diameter, Manou reached a position only 19 km (12 mi) from the eastern Madagascar coastline.
At that time, gale force winds extended over 150 km (90 mi) from the center, and MFR estimated a minimum barometric pressure of 950 mbar (28 inHg).
For about 12 hours, Manou drifted off the eastern coast of Madagascar before turning to the south, moving around a ridge to its east.
Land interaction and drier air weakened the eye, and on May 9 the cyclone weakened to tropical storm status.
The next day Manou weakened to a tropical depression, and the JTWC issued its last advisory.
MFR continued tracking the storm until it dissipated on May 13.
In late April, an area of convection persisted southwest of Diego Garcia in the southern Indian Ocean. The system had a low-level circulation and pulsating thunderstorm activity. Located in an area of weak to moderate wind shear, the convection gradually organized while developing outflow. On May 2, a secondary area of convection, also with an accompanying circulation, formed to the northwest, and also showed signs of development. That day, the original disturbance organized enough for Météo-France (MFR) to designate it Tropical Disturbance 16 at 1200 UTC. The Joint Typhoon Warning Center (JTWC) issued tropical cyclone formation alerts for both systems within a 14‑hour period, and upgraded the original system to Tropical Cyclone 18S on May 3 about 980 km (610 mi) northeast of Mauritius. Due to the disturbance to the northwest, as well as a building ridge to the northeast, the system continued to the southwest. On May 4, MFR upgraded the disturbance to a tropical depression and later Tropical Storm Manou.
According to the JTWC, the storm quickly reached 1-minute sustained winds of 85 km/h (50 mph). The secondary disturbance to the west weakened while approaching the storm. Manou also weakened due to ongoing shear, and the windspeeds dropped as the circulation became exposed from the convection. On May 6, the storm re-intensified and the thunderstorms redeveloped while passing north of Mauritius and Réunion. On May 8 while approaching Madagascar, Manou developed an eye, and as a result, MFR upgraded it to tropical cyclone status, with 10-minute winds of 120 km/h (75 mph). The JTWC also upgraded the storm to the equivalent of a minimal hurricane. After becoming a tropical cyclone, Manou intensified further, although its forward motion slowed significantly. MFR estimated peak 10-minute winds of 155 km/h (95 mph) on May 8, and JTWC estimated peak 1-minute winds of 140 km/h (85 mph), with gusts to 165 km/h (105 mph). This made Manou a rare May tropical cyclone in the basin; only four other storms that formed in the south-west Indian Ocean in May reached winds of over 140 km/h (85 mph) since satellite coverage began, most recently Cyclone Kesiny in the previous year.
While maintaining its peak intensity and an eye 44 km (28 mi) in diameter, Manou reached a position only 19 km (12 mi) from the eastern Madagascar coastline. At that time, gale force winds extended over 150 km (90 mi) from the center, and MFR estimated a minimum barometric pressure of 950 mbar (28 inHg). For about 12 hours, Manou drifted off the eastern coast of Madagascar before turning to the south, moving around a ridge to its east. Land interaction and drier air weakened the eye, and on May 9 the cyclone weakened to tropical storm status. The next day Manou weakened to a tropical depression, and the JTWC issued its last advisory. MFR continued tracking the storm until it dissipated on May 13.
Cyclone Manou