Very heavy rainfall was reported at isolated locations across Tamil Nadu and Kerala during 24 hours ending Thursday morning as a well-endowed low-pressure area parked over the South-West Bay of Bengal off the coast of Sri Lanka set about its task of putting both States on notice.
More rain is forecast for not only these states, but also the surrounding area, with the India Meteorological Department (IMD) predicting fairly widespread to widespread rain, with isolated heavy rainfall over the Indian islands and the Peninsula, scattered to fairly widespread rainfall over the north.
Rapidly filling reservoir
The ‘low’ has potential ramifications for Kerala and Tamil Nadu, as rains have begun to fill the vulnerable Mullaperiyar reservoir, which stands on the inter-state border in Kerala’s Idukki district. The Supreme Court is considering whether to open the shutters of the lime-and-surkhi structure.
To compound the contender states’ woes, the ‘low’ will take its own time (two days) to cross the South Peninsula, increasing its rain-generating potential by a factor of two. According to the IMD, a helpful trough in the easterly winds runs from this low-pressure area to the North-West Bay of Bengal.
Increased potential for rainfall
For the next five days, the ensemble will produce isolated/few areas of heavy to very heavy rainfall over Tamil Nadu, as well as isolated heavy rainfall over Kerala and Mahe. Coastal Andhra Pradesh is expected to receive heavy rain until October 31, with isolated very heavy falls on Friday (tomorrow).
Heavy to very heavy rain is forecasted in South Interior and Coastal Karnataka on Sunday, as well as Rayalaseema of Andhra Pradesh on Friday and Saturday.
Thunderstorms and lightning could strike Kerala, Mahe (also known as Mayyazhi), Tamil Nadu, Puducherry, Karaikal, and Coastal Andhra Pradesh until Sunday, and Rayalaseema from Friday to Monday.
As per the extended forecast valid until November 4, fairly widespread to widespread rainfall with isolated heavy falls may lash the Islands and South Peninsula, with scattered to fairly widespread rain over the North Peninsula.
Meanwhile, the US National Weather Service’s Climate Prediction Centre has to forecast above-normal rainfall for the South Peninsula, primarily Kerala and Tamil Nadu, beginning November 3, presumably after the ‘low’ cross the peninsula and enters the Arabian Sea.