Chennai, which put up with an overcast weather and steady showers throughout Tuesday, braced for heavy rains with cyclone Nilam — packing in winds of up to 85 kmph — expected to hit the Tamil Nadu coast Wednesday afternoon.
Schools and colleges, which did not open on Tuesday in anticipation of heavy cyclonic rain, will remain closed on Wednesday. Fishermen too will have to stay off the sea for the third consecutive day since Monday as the sea would be rough.
The meteorological department has directed danger signal no. 7 to be hoisted at Chennai port and danger signal no. 6 at Ennore port. This is to indicate that the cyclone would slam the coastline closer to Chennai port and slightly away from Ennore port.
The danger signals vary from distant cautionary warning, which denotes the prevalence of a cyclone that may not affect the port area, to danger signals and great danger signals, signifying the proximity of the cyclone hitting the coastline near the port. Danger singal no. 1 signifies the least harm to the port.
Chennai Corporation commissioner D. Karthikeyan said the entire civic body machinery was on high alert. The four community kitchens and 280 civic body-run schools were readied to handle emergencies.
“An advance of Rs. 1 lakh each has been given to zonal officers in case they have to procure anything for relief centres. The Corporation will continue to watch the scenario and in case we have to evacuate people, we will swiftly get into action.”
As of Tuesday evening, according to the weather bulletin, Nilam lay centred about 450 km south-southeast of Chennai and 130 km east-northeast of Trincomalee.
It is expected to move northwest and cross north Tamil Nadu and south Andhra Pradesh coast between Cuddalore and Nellore by Wednesday afternoon.
Y.E.A. Raj, deputy director general of meteorology, Regional Meteorological Centre, said the weather models indicated that Nilam may cross 20-30 km south of Chennai, bringing heavy rainfall over the city.
The storm surge, which occurs during cyclones, is expected to go up to a height of one metre. The winds cause the rise in water higher than the usual sea level.
“This may not intensify further into severe or very severe cyclonic storm. It now carries squally winds speeding up to 75 kmph. It may gust up to 85 km per hour when the system moves closer to the coast,” he said.
During the 24 hours till Tuesday morning, Nungambakkam and Meenambakkam recorded 2 cm and 1 cm of rains respectively. It intensified after 8.30 a.m. and flooded main roads across the city and slowed down peak-hour traffic.
By 8.30 p.m., several weather stations around the city recorded significant amount of rainfall.
While Nungambakkam, Taramani and Meenambakkam registered 4 cm of rainfall, those in the fringes, including Madhavaram and Ennore too received 4 cm. Other areas such as Puzhal, Poonamallee and Kolapakkam received 3 cm of rainfall.
Residents of low level areas in Madhavaram and Ambattur zones are already feeling the effects of the heavy rainfall as it has added to water stagnation following the first spell of monsoon rains that is yet to drain off.
Met department officials said Nilam may not cause much wind damage and is more of a marginal cyclonic storm. Storm surge too would not be high.
“We expect damage to thatched huts as the cyclone hits the coast. Tree branches may break and cause minor damage to electricity and communication lines,” Mr. Raj said.
This year, there may not be flooding in the areas along the surplus courses and near reservoirs as the storage level is just one-third of their capacity.
A senior official of the Public Works Department said the four reservoirs have only about 3,700 mcft (million cubic feet) of water against capacity of 11,057 mcft. “We hope the monsoon rains will increase the storage,” the official said.
The department has convened a review meeting to discuss steps to tackle the cyclone’s impact. Besides keeping sand bags ready to handle breaches in water bodies and along the coastline, measures would be taken to remove sand bars accumulated in the rivers.