A low-pressure area has formed over the Southwest Bay of Bengal (BoB), off the North Tamil Nadu and South Andhra Pradesh coast. A trough is extending from the system along the coast and up to west-central BoB. The weather system has strengthened the northeasterly stream along the coastline of Tamil Nadu and Andhra Pradesh. Under the influence of these systems, heavy rains are likely over Chennai and the neighbourhood, lasting between 12th and 15th Nov 2024.
Both, the observatories at Nungambakkam and Minambakkam have received moderate to heavy showers and recorded 36mm and 57mm rainfall respectively, in the past 24 hours. The low-pressure area will move slowly westward across the South Peninsula over the next 2 days. The winter monsoon systems over South India leave a trail of weather, even at the rear of the main system. Therefore, the rains over the capital city will continue for another two days, till 15th Nov 2024.
November is the rainiest month for Chennai with an average of 373.6mm rainfall. There has not been any typical downpour over the city and suburbs, so far, during this month. Nungambakkam and Minambakkam have recorded a total of 99mm and 85mm rainfall between 01st and 12th Nov 2024. Rains over the next 3-4 days will add another 100mm and possibly reach at least the halfway mark. Rains are likely to be intermittent and moderate during this period. But, a few spells could be heavy, resulting in disruption of transportation and connectivity.
The intensity and spread of weather activity will be relatively large, today and tomorrow. The breaks in between may be short and few. The strength of showers will be rather more during evening and night hours. Broad clearance is expected over the area on and after 17th Nov 2024.