Unfortunately, cyclone Vardah is no exception.
There are several WhatsApp messages that contain apocalyptic warnings about a mega flood in store for Chennai and so on.
While heavy rainfall is indeed expected, they are predicted to occur in “north interior Tamil Nadu and adjoining areas of south interior Karnataka and north Kerala” over the next 12 hours, according to the update issued by the Indian Meterological Department at 11:30 AM on Tuesday, Dec 13.
Heavy rainfall is defined as between 64.5 – 124.4 mm. Bangalore has already received around 61 mm of rain in the last 24 hours.
North Interior Tamil Nadu includes the districts of Krishnagiri, Vellore, Dharmapuri and Tiruvannamalai. On the Karnataka side, the affected areas include Chamrajnagar district, Bangalore, Mandya and Mysore.
There are several panic inducing WhatsApp messages in circulation.
However, it should be noted that the rainfall being predicted by the IMD is relatively moderate when compared to that which fell in Chennai last year.
In Chennai, for example, around 500 mm of rain fell in a matter of 24 hours, overwhelming the city’s drainage system. Besides, the devastation in Chennai was accentuated by the lack of open or forested areas that could absorb the water, a factor that is less likely in rural areas.
Vardah has already passed over Chennai and moved into interior Tamil Nadu. As it did so, it caused about 200 mm of rain in Chennai yesterday (Monday).
Some more ‘scattered rains’ are predicted for the city, but nothing that will flood it the way last year’s downpours did.
Some WhatsApp messages, such as the following from last year, are being reforwarded by people.
“If any of your friends or relatives are living in Chennai ask them to leave
Chennai immediately because in the next 72 hours very heavy rain is expected more than multiple level of the present rain. As per NASA Report this is not the ordinary rain. It’s name is EL Nino cyclone. There is a chance for 250 cm rain. Chances are there nearly the entire Chennai may be submerged in water.”
The above message is from last year and not to be relied upon.
As can be seen in the satellite image from 11:30 AM today (Tuesday), the cyclone has degraded itself into a “low pressure area”. It was reclassified as a low pressure area at 8:30 AM today, the IMD said. (Read the full IMD update here 20161213_al_112.)