Most places in the State may continue to receive moderate rain till Wednesday. The ongoing wet spell over the State will extend for more days as the Bay of Bengal may churn out a fresh weather system around Tuesday.
The prevailing cyclonic circulation over southwest Bay of Bengal, off the south Andhra Pradesh-north Tamil Nadu coast, extending up to 4.5 km above mean sea level, will trigger fairly widespread rain over the State for a few more days. On Sunday, nearly 16 districts, including Tiruvallur, Kancheepuram, the Nilgiris and Tiruchi, are likely to get heavy rain in one or two places. Heavy rain may cover a few places in several districts till Wednesday, said officials of the India Meteorological Department (IMD).
On Saturday, many weather stations across the State recorded rain even during the day till 5.30 p.m. Villivakkam received 3 cm, Ennore and West Tambaram 2 cm each and Meenambakkam and Nungambakkam 1 cm each. Aruppukottai in Virudhunagar, Madurai, Valparai and Coimbatore were among the other stations that received rain. Kurinjipadi in Cuddalore district recorded 16 cm, the highest amount of rainfall in the past 24 hours ending 8.30 a.m. on Saturday.
Officials said a fresh low pressure area is likely to form over Southeast Bay of Bengal around November 9 under the influence of an upper air cyclonic circulation over Southeast Bay of Bengal. As it is expected to become more marked and move towards north Tamil Nadu coast in the next two days, it may bring heavy to very heavy rain at a few places over north coastal districts. The department has issued a red alert as extremely heavy rain is possible around November 11 and 12. Fishermen have also been advised to return to coast by Tuesday.
S. Balachandran, Deputy Director General of Meteorology, Chennai, said this year, the low pressure area had sustained the wet weather, with its slow movement and moisture. The next weather system brewing over the Bay of Bengal is expected to bring more rain over north coastal region, including Chennai, and the IMD is monitoring its further development.
Inundation map
To mitigate floods and prevent water logging in the city, the IMD is collaborating with the National Centre for Coastal Research (NCCR) to prepare an inundation map based on its heavy rain forecasts. Inputs such as ward boundaries, elevations and rain received in rivers in upstream regions will be used to run inundation models to develop the map.
M.V. Ramanamurthy, director, NCCR, said the inundation map would provide details on ward-wise locations that are vulnerable to inundation a few days ahead to help government agencies alleviate floods.