Cyclone Arnab is expected to form over the Bay of Bengal, with heavy to very heavy rain forecast across 16 Tamil Nadu districts and authorities warning of landslides, falling rocks, fallen trees and strong winds in several vulnerable areas.
The Chennai Meteorological Centre said a depression over the central and adjoining southeast Bay of Bengal had strengthened by 8.30 am on the day of the report. Its movement subsequently slowed from 8 kmph to 5 kmph, and officials said the system was being monitored closely.
The system may intensify into a deep depression and develop into Cyclone Arnab, the weather centre said. It is expected to strengthen further into a severe cyclonic storm and cross the coast between Andhra Pradesh and Odisha, according to the forecast cited in the report.
Tamil Nadu’s highest recorded rainfall during the preceding period was 20 cm at Devikapuram in Tiruvannamalai district. Nedungunam in the same district recorded 18 cm, while Rishivandiyam in Kallakurichi received 17 cm. Several locations in Kallakurichi, Villupuram, Dharmapuri and Perambalur recorded between 14 cm and 16 cm of rain.
Pudukkottai, Sivaganga and Ramanathapuram districts were placed under an orange alert, with very heavy rain, thunderstorms, lightning and strong winds possible in isolated areas. Heavy rain with thunderstorms, lightning and strong winds was forecast for Kanyakumari, Tirunelveli, Thoothukudi, Tenkasi, Virudhunagar, Madurai, Theni, Dindigul, Karur, Tiruchirappalli, Thanjavur, Tiruvarur and Nagapattinam.
Other parts of Tamil Nadu and Puducherry could receive moderate rain accompanied by thunderstorms, lightning and strong winds. Chennai and its suburbs were expected to remain partly cloudy, with moderate rain and thunderstorms possible in some areas.
The rain alert comes as the state continues to deal with the effects of recent heavy rainfall. The Revenue and Disaster Management Department said 173 fallen trees had been cleared and that 35 landslides or mudslides had occurred in hilly areas.
Two teams of the Tamil Nadu Disaster Management Force and two teams of the National Disaster Response Force have been sent to Ooty in the Nilgiris. Authorities have identified Ooty, other parts of the Nilgiris and Kodaikanal as areas at risk from landslides and falling rocks. Mudslides are also possible in Dindigul, Kolli Hills, Namakkal, Kalvarayan Hills, Kallakurichi, Yelagiri, Tirupathur, Yercaud, Salem, Tiruvannamalai, Valparai and Coimbatore.
The weather-monitoring system in Chennai also faced an operational setback. The Doppler radar installed on the upper floor of the Chennai Port administration building developed a fault, according to information posted on the weather centre’s website. The radar was installed in 2002 and the weather centre plans to replace it completely.
Officials said rainfall warnings for Chennai were still being generated using the radar in Karaikal. Additional information could also be obtained from radar systems at the National Institute of Ocean Technology in Pallikaranai and the Indian Space Research Organisation facility at Sriharikota in Andhra Pradesh. Monitoring of the cyclonic system and rainfall conditions is continuing.
