The Monsoon is not on retreat yet. The MeT department has said monsoon retreat is expected to begin on October 10. This will be the latest ever retreat of a monsoon. The previous latest retreat was recorded in 1961 when the monsoon retreat began on October 1.

The monsoonal rain this year has been the maximum in 25 years. But the India Meteorological Department (IMD) failed to predict that the monsoon would be this strong this year. Heavy rain still continues in Bihar and parts of Karnataka. Half of Bihar is still under floodwater and the other half is struggling to come to terms with the severe drought it has faced.

Uncertain prediction of monsoon was supposed to be the norm when India was technologically backward and economically a minor player. With the economic boom in India, funds went into monsoon research and led to the development of a new model -- Monsoon Mission Coupled Forecast Model, abbreviated as CFS (standing for Coupled Forecast System) -- that promised to predict the season weather pattern accurately and prevent Indian farmers and people from the vagaries of the monsoonal uncertainty.

Some Rs 1,200 crore is said to have been spent on developing the model. But in its latest update - on August 1 - the IMD failed to predict that August and September rainfall would be 130 per cent of the average rainfall for the month. This might explain to an extent the unpreparedness of the administration, particularly in Bihar.

The IMD said on August 1 that the monsoonal rain would be 100 per cent of what is normal with a variation of 8 per cent. On the higher side, monsoon has proved to be 22 percentage points stronger.

Some independent weather scientists, writing analyses in various publications, expressed surprise at the inability of the IMD's dynamic monsoon model to correctly predict the amount of monsoonal rain. They point to two key reference points that the IMD missed in assessing the strength of monsoon.

One was the Indian Ocean Dipole, which gives an indication of the temperature condition for the sustenance of monsoon over mainland India. The readings were favourable at the end of July for a very strong monsoonal wind in August and September. But the IMD model failed to this factor in, somehow.

The other factor, the experts said, was a weaker El Nino till almost middle of August. This meant the temperature in the Indian Ocean towards the mainland India was higher. This translates into a stronger flow of monsoon over India.

IMD officials, in their media interactions, have admitted to the failure of the model to give accurate predictions but attributed it to weather circumstances that they said were fast-changing in nature. Simply put, these changes are not predictable. But other weather scientists wrote columns predicting a stronger monsoon.

There is another point in case. This year is not a singular year when the IMD has failed to predict monsoon correctly. In 2017, IMD said monsoon prediction has improved in recent years and claimed accuracy of 90 per cent for 1988-2008.

However, its record over the last few years has been dismal. The IMD has got a correct prediction only once since 2014 (in 2015). These years have also been part of a period when the climate change debate has dominated the environmental space.

In 2012, the IMD predicted that the monsoon would bring 104 per cent of the long period average of rainfall. The actual was at 93 per cent. The 2013 prediction was in the range of accuracy. The IMD model predicted 104 per cent of long period average. It was 106 per cent of LPA.

In 2014, the actual rainfall was 88 per cent against the prediction of a normal monsoon by the IMD at 96 per cent of average rainfall. Modi government was welcomed with two consecutive drought years.

Another stark gap was witnessed in 2016, when the IMD's dynamic CFS model predicted monsoonal rain at 112 per cent. The actual was 97 per cent. The actual rainfall that year was in the zone of normal monsoon, which came after two consecutive years of drought.

This year, IMD's CFS model predicted a 97 per cent of the normal, but the monsoon has already brought 110 per cent of rainfall. For a country like India, where farmers still depend on monsoon for irrigation, the general population for drinking water, correct prediction of monsoon becomes a key factor for the overall well-being of the country and its economy. A correct prediction might also awaken a usually laid-back administration for rescue efforts if and when needed. Bihar flood is a case in point.

Also read: India monsoon to withdraw from October 10, marking most delayed retreat

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