Cyclone Dina

Intense Tropical Cyclone Dina

Intense tropical cyclone (SWIO scale)
Category 4 (Saffir–Simpson scale)
Tropical Cyclone Dina at peak intensity on January 20
Formed	January 17, 2002
Dissipated	January 28, 2002 (extratropical after January 25)
Highest winds	10-minute sustained: 215 km/h (130 mph) 1-minute sustained: 240 km/h (150 mph)
Lowest pressure	910 hPa (mbar); 26.87 inHg
Fatalities	5 direct, 10 indirect
Damage	$287 million (2002 USD)
Areas affected	Mauritius, Réunion
Part of the 2001–02 South-West Indian Ocean cyclone season

Intense Tropical Cyclone Dina was a cyclone that caused record flooding across parts of Réunion. Originating from a tropical disturbance on 15 January 2002 near the Chagos Archipelago, the precursor to Dina quickly developed within a region favoring tropical cyclogenesis. By January 17, the system had developed enough organized convection as it moved southwestward to be declared a tropical depression. Rapid intensification occurred shortly thereafter, with the system attaining winds in excess of 120 km/h (75 mph) on January 18. Dina achieved its peak intensity on January 20 as an intense tropical cyclone winds of 215 km/h (130 mph). Hours after reaching hits strength, the storm bypassed Rodrigues Island about 150 km (93 mi) to its north. On January 21, the storm brushed Mauritius and Réunion as an intense tropical cyclone before turning southward. Once on a southward course, steady weakening ensued and the system eventually transitioned into an extratropical cyclone on January 25. The remnants of the storm accelerated southeastward and were last noted on January 28 before being absorbed into a polar trough.

Across Mauritius and Réunion, torrential rains and destructive winds from the cyclone resulted in extensive to "catastrophic" damage. The entire island of Mauritius lost power during the storm and widespread structural damage took place. Agricultural and property damage amounted to US$47 million and US$50 million respectively in the republic. Nine fatalities were attribute to the storm in Mauritius: five off the coast of Rodrigues Island and four on the main island. More extensive damage was seen on Réunion where up to 2,102 mm (82.8 in) of rain fell over three days. Record to near-record flooding destroyed many homes, washed out roads, and caused catastrophic agricultural damage. Destructive winds, measured up to 280 km/h (170 mph) also crippled communications. In all, six people died on the island and losses were estimated at €200 million (US$190 million).

On January 15, a tropical disturbance began organizing near the Chagos Archipelago in the South Indian Ocean convergence zone, which is an extended area of convection connected to the monsoon. The thunderstorms gradually organized, associated with a weak circulation and located within an area of moderate wind shear. A distinct low pressure area developed on January 16, about 750 km (470 mi) east of Diego Garcia. The thunderstorms were primarily located along the western periphery due to continued shear, and ordinarily would prevent significant development. The system moved to the southwest along the north side of a ridge, and despite the shear it developed into a tropical disturbance late on January 16. Subsequently, the system rapidly organized, developing rainbands as the convection increased.