After a string of monsoon predictions by the India Meteorological Department going haywire for parts of north India, including Delhi, one of its senior scientists has explained the reasons behind the faulty forecasts. "The declaration is based on observation. A forecast is based on different tips like winds, system movement, cloud movement etc. All components are active, just rain is expected," said RK Jenamani.
"There is nothing wrong about the predictions for Delhi. We will study why there has been no rainfall in Delhi. Wind is there and temperature is down, our concern is just rain right now," he said as the monsoon rain is running behind schedule in the national capital.
In its latest update, the IMD said thunderstorms with light to moderate intensity rain would occur over Delhi and its adjoining areas today.
12/07/2021: 15:25 IST; Thunderstorm with light to moderate intensity rain and winds with speed of 20-40 Km/h would occur over and adjoining areas of isolated places of Delhi, North-East Delhi, East Delhi, NCR ( Noida, Ghaziabad) Sonipat, Aurangabad, Palwal (Haryana)— India Meteorological Department (@Indiametdept) July 12, 2021
The Southwest Monsoon has reached almost all parts of the country but has stayed away from Delhi, Haryana, parts of west Uttar Pradesh and west Rajasthan. The weather forecasting agency had predicted that monsoon is expected to cover these parts by June -- a little less than a month back, but its predictions are yet to come true.
Mr Jenamani said that temperature goes down with the advent of Southwest Monsoon, and it has already been experienced in Rajasthan, Punjab and some parts of Haryana.
"Monsoon was forecasted for June 27, but it's delayed," said the IMD scientist.
On June 13, the IMD had predicted that the Southwest Monsoon will reach Delhi by June 15. A day later, however, it said conditions are not favourable for its further advancement in the region. In its forecast on July 1, the agency predicted further advancement of the monsoon by July 7. The moist easterly winds in the lower level from the Bay of Bengal are likely to establish gradually over parts of eastern India from July 8, it had said.
Again, on July 5, the IMD said the monsoon is likely to spread into northwest India covering Punjab and north Haryana by July 10. There were no signs of relief even on July 10.
The IMD scientist, however, denied the reports of four faulty predictions and said "we just gave two predictions".
"We gave June 15 and July 10 as the dates and changes were seen. There was cloud formation," he said.
M Rajeevan, Secretary, Ministry of Earth Sciences had earlier said that the IMD's forecast of advancement of monsoon over parts of north India, including Delhi, was too early. The IMD should not have issued the forecast. They could have waited for some more time, he said. The IMD is an institute under the Ministry of Earth Sciences.
In a normal scenario, The Southwest Monsoon covers West Bengal and many parts of central India by June 15, just 14 days after it makes an onset over Kerala, making the official commencement of the four-month rainfall season over the country. It, however, takes nearly three weeks to cover parts of north India, former IMD Director General KJ Ramesh said. This also depends on the interactions of easterlies and westerlies, he added.
The IMD must have seen some strength of monsoon capable of moving westwards towards north India which is why they issued the forecast, he explained.