North Tamil Nadu and South Coastal Andhra Pradesh has witnessed heavy rains in the past 24 hours. Chief amounts of rainfall: Nungambakkam-72mm, Meenambakkam-62mm, Kavali-149mm, Ongole- 74mm and Bapatla-47mm. Moderate showers were witnessed elsewhere all along the coastline of Andhra Pradesh and Tamil Nadu. Even the interiors also were lashed with fairly widespread moderate showers, as a precursor to the arrival of Northeast Monsoon.
There are multiple weather systems, working in tandem, to trigger widespread weather activity over the South Peninsula. There is a cyclonic circulation, just next to the coast of Tamil Nadu over the Southwest Bay of Bengal (BoB). Another circulation is marked over North Kerala, Coastal Karnataka and the adjoining Arabian Sea. Yet another system a well-marked low-pressure area is lying over central parts of South BoB. An east-west oriented trough is joining these three systems adding further strength to the intensity and spread of weather.
The cyclonic circulation over Southwest BoB and the low pressure will move west-northwest, towards Chennai, flanked by Pondicherry on the left and Kavali on the right. The capital city of Chennai and the other two locations are at risk of very heavy rainfall over the next two days, today and tomorrow. The rainfall will continue for the rest of the week as well but with reduced severity.
Chennai will continue to have heavy bursts of showers throughout the day with short breaks in between. The wet spell is expected to become more intense during the night and tomorrow. Some spells of blinding rains can not be ruled out. These may cause water logging and inundation in some areas. The rail, road and air traffic may also be hit, leading to inconvenience for commuters. There is a need to observe and exercise a lot of caution to avert any mishaps.