CHENNAI: Battered and bruised, Chennai is set to face a litmus test in the 24 hours starting 8.30 am Thursday, as the city once again comes under a massive cloud convergence being formed over south Andhra Pradesh and north Tamil Nadu.
The Indian Meteorological Department (IMD) said the low pressure area, which lies in southeast and adjoining southwest Bay of Bengal, and has an associated cyclonic circulation extending up to 5.8 km above mean sea level, was on track to hit south Andhra Pradesh and north Tamil Nadu by Thursday.
The Regional Meteorological Centre has sounded a red alert from 8.30 am on Thursday to 8.30 am on Friday for Chennai, Kancheepuram and Ranipet, where heavy to very heavy rain is expected. An orange alert was also issued for Tiruvannamalai, Villupuram, Cuddalore, Chengalpattu, Tirupattur and Vellore.
District Collectors have declared a holiday for schools and colleges in Chennai, Tiruvallur, Vellore and Ranipet districts for Thursday. In Kancheepuram and Chengalpattu, only schools will remain shut.
As per estimates, weather stations in Chennai and the northern districts may clock a rainfall of 15-20 cm or more in the 24-hour window ending 8.30 am on Friday, which would be enough to cause extensive damage and flooding. Weather models also indicate the formation of another new system to bring rains next week.
Chennai surpassed its monthly average rainfall within the first week of November itself, with the Nungambakkam observatory recording a total of 464 mm of rains from November 1 to 9. The 215 mm of rainfall Chennai received on November 7 is the second-highest amount of rainfall recorded in the city in a span of 24 hours in November in the last decade.
City witnessing 65 per cent excess rains
Th e all-time record for the amount of rainfall the city received in a span of 24 hours stands at 452.4 mm, which was recorded on November 25, 1976. Chennai has been recording good rains ever since the beginning of the northeast monsoon.
The State capital is witnessing excess rains by 65 per cent, with 815.5 mm of rains received against the normal of 495.6 mm (from October 1 to November 17). The State, in total, has received an excess of 54 per cent rains.
Not just Chennai, all neighboring districts have been receiving record rains. Chengalpattu received excess rainfall of 65 per cent, Kancheepuram 38 per cent and Tiruvallur 51 per cent.
Holiday for educational institutions
Holiday is declared for schools and colleges in Chennai, Tiruvallur, Vellore and Ranipet districts for Thursday. In Kancheepuram and Chengalpattu, only schools will remain shut