CHENNAI: In a significant development, the Indian Meteorological Department (IMD) and the Tamil Nadu government have decided to set up additional Doppler X-band radars in two or three new locations in southern and interior districts of the state to improve the accuracy of weather forecasting.
IMD will also soon replace the old S-band radars in Chennai and Sriharikota for which tenders have already been issued.
M Ravichandran, secretary, Ministry of Earth Sciences, and Mrutyunjay Mohapatra, Director General of Meteorology, IMD, said this during a press conference in Chennai while replying to a query from TNIE. Site studies in Ramanathapuram and Yercaud are currently on. S Balachandran, head, Regional Meteorological Centre, said, “We are checking for locations that don’t have electromagnetic interference.”
Tamil Nadu has been witnessing a series of extreme weather events during monsoon seasons, and forecast has become a challenge because of lack of good radar coverage across the state.
Also, there were instances in the past, especially during 2022 rains, when Chennai’s S-band radar went defunct, X-band radar in National Institute of Ocean Technology (NIOT) was not fully calibrated, and Sriharikota radar was stretched to its full capacity making it difficult for the meteorologists to pick up rain bands that hit Chennai by surprise.
The city had received a record rainfall of 21cm in 24 hours from November 6 to November 7, 2022.
‘TN govt sets rainfall stations in more than 1,000 places’
Later, Chief Minister M K Stalin took a decision to augment the weather forecasting system by setting up additional radars across the state. IMD chief Mohapatra said the state government is also installing ground observatories (rainfall stations) in more than 1,000 places whose data will also be used for forecast modelling.
“Currently, six radars --- two in Chennai, and one each in Karaikal, Sriharikota, Trivandrum, and Kochi --- are providing coverage for Tamil Nadu. Within a year, C-band radar will be installed in Bengaluru which will cover some parts of the state. With the help of these radars, we can go for panchayat-level weather forecasting,” he said.
To a query, Ravichandran said tenders for replacing the aging radars in Chennai and Sriharikota have been issued. “Totally, four new S-band radars will be installed on the east coast. In another four to five months, IMD will be augmenting 20 petaflops computers from current four petaflops, which will improve the resolution from 10 km to 6km and will enable the Met office to predict more localised weather events,” he said
Mohapatra said IMD has extended the heat action plan to Tamil Nadu and introduced terminology like hot and humid weather as the water holding capacity of air is increasing with rising temperature. S K Prabhakar, Additional Chief Secretary and Commissioner of Revenue Administration, also requested the meteorologists to use the data from the state’s 1,400 rain stations that are being installed for giving more localised (firka-level) forecast which will help disaster managers in handling the situation better.