2000 Sri Lanka Cyclone - Meteorological History

Meteorological History

An area of atmospheric convection developed and persisted on December 21 in the central Bay of Bengal forming within an active near-equatorial trough. Located within an area of weak vertical wind shear, the system steadily organized, and after initially remaining nearly stationary it began to move slowly westward. Deep convection continued to develop, and on December 23 a mid-level circulation began to form. Later that day, the Joint Typhoon Warning Center (JTWC) issued a Tropical Cyclone Formation Alert. By the night of the December 23, a low-level circulation developed in the system, located to the south of the deep convection. The disturbance continued to organize, with the India Meteorological Department (IMD) classifying it as a deep depression early on December 24. Later that day, the organization of the system degraded slightly, though it quickly reorganized. On December 25, the Joint Typhoon Warning Center initiated advisories on Tropical Cyclone 04B while it was located about 155 miles (250 km) east of Sri Lanka. On the center's first advisory, the tropical storm was drifting west-northwest at 3 mph (5 km/h) with maximum sustained winds of 45 mph (70 km/h). Shortly thereafter, the IMD upgraded the deep depression to a cyclonic storm as a central dense overcast developed over the center.

A subtropical ridge to the north of the cyclone resulted in it continuing generally westward. Deep convection continued to develop over the center of circulation, and the storm steadily strengthened as outflow improved throughout the circulation. By late on December 25, a rainband wrapped tightly into the center, and it intensified into a severe cyclonic storm as it approached the coast of Sri Lanka. The next day the cyclone developed an eye as it turned west-southwestward. On December 26, the cyclone made landfall on near Trincomalee, Sri Lanka. The JTWC assessed the cyclone as attaining peak winds of 75 mph (120 km/h). However, the IMD estimated the cyclone reached a maximum intensity of 105 mph (165 km/h), making it a very severe cyclonic storm. It weakened slightly over land and emerged into the Gulf of Mannar early on December 27 as a tropical storm. Initially, forecasters predicted it to slowly re-intensify; instead it weakened as its convection degraded in organization and intensity. After turning west-northwestward, the storm struck southern India near Kanyakumari on December 28 with winds of 45 mph (70 km/h), with minimal convection due to land interaction and increased wind shear. It rapidly weakened to tropical depression status over land, and its remnants degenerated into a low pressure area after emerging into the eastern Arabian Sea early on December 29.