Chennai rain: Parrys, Kathivakkam log over 300 mm overnight; more heavy spells forecast

North Chennai bore the brunt of an exceptionally intense spell of rain on Saturday night, 17 October, with a handful of rain gauges in the city recording more than 300 mm in a single day. The Regional Meteorological Centre (RMC) in Chennai has forecast further heavy to very heavy rain over the city and its surroundings on Sunday.

How much rain fell

Figures for the 24 hours ending 8.30 am on 18 October, as reported by DT Next citing RMC data, placed six locations in the “extremely heavy” bracket, which begins above 204.4 mm:

• Parrys: 363.4 mm
• Kathivakkam: 344.4 mm
• Meenambakkam: 285.8 mm
• Chennai Central: 274.5 mm
• Tiruvottiyur: 224.4 mm
• Ennore: 215.8 mm

The city as a whole averaged close to 106 mm, the report said, with 17 places logging very heavy rain and another 18 logging heavy rain. Oneindia, using totals counted only up to midnight, put Kathivakkam at 310.2 mm and Parrys at 300.9 mm, and said it was the first time during this northeast monsoon that two stations had crossed 300 mm. The gap between the two sets of numbers reflects the different cut-off times used. According to Oneindia, close to half of Kathivakkam’s total came down within a single hour between 9.30 pm and 10.30 pm.

Waterlogging and civic response

Low-lying pockets including AGS Colony in Velachery, Prakasam Road in Broadway and Ice House in Triplicane were inundated, DT Next reported. A 30-member rescue team equipped with six boats was stationed in AGS Colony. Oneindia reported waterlogging in parts of Perambur, Thiruvottiyur and Royapuram, and said the Greater Chennai Corporation had received seven complaints of stagnation, most of which had been cleared. Water on several roads was receding by Sunday morning, according to residents quoted by DT Next.

In western Tamil Nadu, an unused three-storey building nearly 60 years old collapsed in Erode on Saturday afternoon after tilting, damaging an electricity pole, Oneindia reported. No one was hurt.

What the forecast says

Satellite pictures show strong cloud build-up over north coastal Tamil Nadu and nearby seas, tied to a cyclonic circulation in the upper air, according to DT Next. Weather blogger Pradeep John, quoted by Oneindia, said a nearly stationary circulation over Chennai, unusually warm sea surface temperatures and heat accumulated over about 25 dry days combined to produce the downpour. He added that a separate circulation over the southwest Arabian Sea could develop into a low-pressure area by Monday.

• Heavy rain is possible at isolated places in Chennai, Tiruvallur, Chengalpattu, Kancheepuram, Villupuram, Cuddalore, Salem, Krishnagiri and the Nilgiris, Oneindia reported.
• An orange alert for heavy to very heavy rain on 20 October covers the Nilgiris, Coimbatore, Tiruppur, Dindigul, Theni, Tenkasi, Virudhunagar, Tirunelveli and Kanniyakumari.

A PTI report carried by Deccan Herald said the weather office had put 17 districts under a yellow alert and expected heavy rain across the state until 23 October. Dainik Jagran English reported on Sunday afternoon that sudden bursts of 6 to 10 cm in under an hour had caused waterlogging and traffic jams in parts of Chennai.

No school holiday for Chennai or neighbouring districts had been announced in these reports as of Sunday afternoon. Parents should watch for announcements from district collectors.

Sources: DT Next, Oneindia, Deccan Herald (PTI), Dainik Jagran English