Very Severe Cyclonic Storm Thane was the strongest

tropical cyclone A tropical cyclone is a rapidly rotating storm system characterized by a low-pressure center, a closed low-level atmospheric circulation, strong winds, and a spiral arrangement of thunderstorms that produce heavy rain and squalls. Depen ...

of 2011 within the

Bay of Bengal The Bay of Bengal is the northeastern part of the Indian Ocean, bounded on the west and northwest by India, on the north by Bangladesh, and on the east by Myanmar and the Andaman and Nicobar Islands of India. Its southern limit is a line betwee ...

. Thane initially developed as a tropical disturbance within the

monsoon trough The monsoon trough is a portion of the Intertropical Convergence Zone in the Western Pacific,Bin WangThe Asian Monsoon.Retrieved 2008-05-03. as depicted by a line on a weather map showing the locations of minimum sea level pressure, and as such, ...

to the west of

Indonesia Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania between the Indian and Pacific oceans. It consists of over 17,000 islands, including Sumatra, Java, Sulawesi, and parts of Borneo and New Guine ...

. Over the next couple of days the disturbance gradually developed further while moving towards the northwest, and was declared a Depression during December 25, before being named Cyclonic Storm ''Thane'' the next day. Thane started to turn towards the west under the influence of a subtropical ridge of

high pressure In science and engineering the study of high pressure examines its effects on materials and the design and construction of devices, such as a diamond anvil cell, which can create high pressure. By ''high pressure'' is usually meant pressures of th ...

before its development slowed during December 27, as a strong outflow and marginally favourable sea surface temperatures fought with persistent

vertical wind shear Wind shear (or windshear), sometimes referred to as wind gradient, is a difference in wind speed and/or direction over a relatively short distance in the atmosphere. Atmospheric wind shear is normally described as either vertical or horizonta ...

. After its development had slowed during December 27, Thane became a Very Severe Cyclonic Storm during December 28, before as it approached the Indian states of

Tamil Nadu Tamil Nadu (; , TN) is a state in southern India. It is the tenth largest Indian state by area and the sixth largest by population. Its capital and largest city is Chennai. Tamil Nadu is the home of the Tamil people, whose Tamil language ...

, it weakened slightly. Thane then made landfall early on December 30, on the north Tamil Nadu coast between Cuddalore and

Puducherry Puducherry or Pondicherry may refer to: * Puducherry (union territory), a union territory of India ** Pondicherry, capital of the union territory of Puducherry ** Puducherry district, a district of the union territory of Puducherry ** Puducherry t ...

and rapidly weakened into a depression.

Meteorological history

On December 23, the

Joint Typhoon Warning Center The Joint typhoon Warning Center (JTWC) is a joint United States Navy – United States Air Force command in Pearl Harbor, Hawaii. The JTWC is responsible for the issuing of tropical cyclone warnings in the North-West Pacific Ocean, South P ...

(JTWC) reported that a tropical disturbance had developed within the

about 1540 km (960 mi) to the east of

Medan Medan (; English: ) is the capital and largest city of the Indonesian province of North Sumatra, as well as a regional hub and financial centre of Sumatra. According to the National Development Planning Agency, Medan is one of the four mai ...

. Convection surrounding the system had started to consolidate over a weak low level circulation centre, that was being fed by an enhanced westerly flow associated with the precursor system to Tropical Cyclone Benilde. Over the next couple of days the disturbance gradually developed further while moving towards the northwest, with a

Madden–Julian oscillation The Madden–Julian oscillation (MJO) is the largest element of the intraseasonal (30- to 90-day) variability in the tropical atmosphere. It was discovered in 1971 by Roland Madden and Paul Julian of the American National Center for Atmospheric ...

increasing the system

boundary layer In physics and fluid mechanics, a boundary layer is the thin layer of fluid in the immediate vicinity of a bounding surface formed by the fluid flowing along the surface. The fluid's interaction with the wall induces a no-slip boundary cond ...

s rotation. The JTWC then issued a

Tropical Cyclone Formation Alert A Tropical Cyclone Formation Alert (TCFA) is a bulletin released by the U.S. Navy-operated Joint Typhoon Warning Center in Honolulu, Hawaii or the Fleet Weather Center in Norfolk, Virginia, warning of the possibility of a tropical cyclone formin ...

on the system during December 25 before designating as Tropical Cyclone 06B later that day as 1-minute wind speeds near the centre reached which is equivalent to a tropical storm. The India Meteorological Department (IMD) also reported during December 25 that the disturbance had organised sufficiently to be declared Depression BOB 05, while it was located about to the southeast of Chennai, India. Early on December 26, the IMD reported that the depression had intensified into a Deep Depression, before later that day reporting that it had intensified into a

cyclonic storm In meteorology, a cyclone () is a large air mass that rotates around a strong center of low atmospheric pressure, counterclockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere as viewed from above (opposite to an anti ...

and named it Thane. As it was named, Thane started to turn towards the west under the influence of a subtropical ridge of high pressure before its development slowed as strong outflow and marginally favourable sea surface temperatures fought with persistent easterly vertical wind shear. Early on December 28, the JTWC reported that Thane had become equivalent to a category one hurricane on the Saffir–Simpson hurricane wind scale with 1-minute sustained windspeeds of , while an eye feature had become visible on microwave imagery. Later that day the IMD reported that Thane had become the first Very Severe Cyclonic Storm of the season, with 3-minute sustained windspeeds of . During December 28, Thane continued to intensify, and developed a small pinhole eye of about 20 km (10 mi), before the JTWC reported that Thane had peaked early on December 29 with 1-minute sustained wind speeds of . The IMD then followed suit and reported that the system had peaked as a Very Severe Cyclonic Storm with 3-minute sustained windspeeds of . During the rest of that day, the system continued to move westwards and weakened slightly as it started to interact with land. Thane then made landfall as a borderline very severe cyclonic storm during December 30 on the north Tamil Nadu coast between Cuddalore and Puducherry. After it had made landfall, frictional forces made Thane rapidly weaken into a depression. As a result, the JTWC issued their final advisory during December 30, while the IMD continued to monitor the remnants of Thane until the depression weakened into a well-marked low-pressure area early on December 31.

Preparations and Impact

Tamil Nadu and Puducherry

Forty eight people were killed by Cyclone Thane. About 9 deaths were reported in Puducherry and 39 people were reported dead in

Cuddalore Cuddalore, also spelt as Kadalur (), is the city and headquarters of the Cuddalore District in the Indian state of Tamil Nadu. Situated south of Chennai, Cuddalore was an important port during the British Raj. While the early history of Cudda ...

. Cuddalore and Puducherry were the worst affected by Thane. The storm made Cuddalore inaccessible by damaging road network and the

National Disaster Response Force The National Disaster Response Force (NDRF) is an Indian specialized force constituted "for the purpose of special response to a threatening disaster situation or disaster" under the Disaster Management Act, 2005. The "Apex Body for Disaster M ...

and fire and rescue services had difficulty in reaching the cyclone affected fishing hamlets. Fishing activities had come to a complete halt in the cities of

Chennai Chennai (, ), formerly known as Madras ( the official name until 1996), is the capital city of Tamil Nadu, the southernmost Indian state. The largest city of the state in area and population, Chennai is located on the Coromandel Coast of th ...

Tiruvallur Tiruvallur is a Grade I municipality and a fast developing city in the Indian state of Tamil Nadu. It is located on the banks of Coovum river about from downtown Chennai (Madras) and just 5 km from megacity border, in the western p ...

and Kanchipuram in the wake of the storm after the warnings by the weather department were received. About 10,000 fishing boats were moved to safer locations in all fishing hamlets in these areas.

Chennai Corporation The Greater Chennai Corporation, formerly known as the Corporation of Madras (1688-1996) and Corporation of Chennai (1996-2016), is the civic body that governs the city of Chennai in the Indian state of Tamil Nadu. Inaugurated on 29 September ...

kept its four permanent relief centers (

Basin Bridge Basin Bridge Junction is a station on the Chennai Suburban Railway and serves the locality of Basin Bridge, the confluence on the Otteri Nullah and Buckingham Canal, in Chennai, India. The station is located at the southern end of the 'diamo ...

, Chintadripet, Gopalapuram and

Perambur Perambur is a neighbourhood located in the northern region of Chennai, Tamil Nadu, India. Etymology In Tamil, ''pirambu (பிரம்பு)'' means bamboo and ''ur (ஊர்)'' means city or place. Before British rule, this place was w ...

Barracks Road) ready to accommodate people in case of evacuation due to torrential rains. People from low-lying areas were shifted to community centers with adequate arrangements of food and medical round the clock. Tamil Nadu Chief Minister

Jayalalithaa Jayaram Jayalalithaa (24 February 1948 – 5 December 2016) was an Indian politician and actress who served as Chief Minister of Tamil Nadu for more than fourteen years over six terms between 1991 and 2016. From 9 February 1989 to 5 December 2 ...

ordered the immediate release of 150 crore towards relief and restoration of infrastructure damaged by the Cyclone Thane. She also directed the District Collectors, Deputy Collectors and department Secretaries to assess the extent of the damage caused by Cyclone Thane.

Andhra Pradesh

700 fishermen were reported to be stranded near the Nizampatnam Bay area due to the rough sea conditions near the coast due to the cyclone. Owners had asked the government as well as the National Coast Guard for the fishermen's search and rescue after they could not communicate with them. The former chief minister of Andhra Pradesh,

Nallari Kiran Kumar Reddy Nallari Kiran Kumar Reddy (born 13 September 1959) is an Indian politician who served as the 16th Chief Minister of Andhra Pradesh between 25 November 2010 and 1 March 2014. He was the last Chief Minister of the United Andhra Pradesh before th ...

instructed all the district collectors of the concerned districts of the state, mainly

Nellore Nellore is a city located on the banks of Penna River, in Nellore district of the Indian state of Andhra Pradesh. It serves as the headquarters of the district, as well as Nellore mandal and Nellore revenue division. It is the fourth most p ...

and Prakasam districts to take all precautionary measures in anticipation of the approaching storm.

APSRTC Andhra Pradesh State Road Transport Corporation (APSRTC) is the state-owned road transport corporation in the Indian state of Andhra Pradesh. Its headquarters is located at NTR Administrative Block of RTC House in Pandit Nehru bus station of ...

was asked to keep sufficient buses in reserve in case of evacuation of the people. Officials reported that food stocks, drinking water, emergency power etc. were kept ready in reserves.

References

External links