New Delhi: Even though the monsoon has covered almost all states of the country, deficient rains in the southern parts of the country continue to push several states into drought-like conditions.
According to India Meteorological Department (IMD), the rain deficit in the southern peninsula has risen to 28%, which is the highest among all the four sub-divisions of the country. As on Saturday, as many as seven subdivisions in the south including Kerala, Tamil Nadu, Rayalseema, Andhra Pradesh, Telangana, Marathwada and Vidarbha reel under a rain deficit of up to 60%.
This is in line with the second long range forecast of the IMD in June, wherein it has predicted below normal rains at 95 % of the long-period average (LPA) of 89 cm for July when monsoon covers the entire country. The rains are extremely crucial for the rain-fed Kharif crops planted during the month.
As per a recent Reserve Bank of India (RBI) analysis of past monsoon forecasts, the IMD’s monsoon forecast has recorded the highest error in projecting the monsoon rains for the southern peninsula out of all the four sub-divisions.
“The forecasts tend to over-project rainfall in the East and North East and Southern peninsula in 77 % and 50 % of the time, respectively. However, the forecasts have been correct for North West nearly 50 % of the time with lowest mean root square error," stated the analysis, which compares the IMD's second stage long range forecast released in May- June every year with actual rainfall, starting 2003.
This year, the IMD has predicted the seasonal rainfall to be normal at 97% of LPA for southern peninsula and 100% of LPA for Central India, but below normal for northwest India at 94% of LPA and north-eastern states at 91% of LPA. The predictions carry a model error of ± 8 %.
The Second Stage Long-Range Forecast (SSLRF) which gives prediction of rainfall for all four subdivisions of the country was introduced by IMD in June 2003, after its First Stage Long-Range Forecast (FSLRF) which is released in April failed to predict the massive drought of 2002.
Out of the 24 years since 1995, FSLRF had over-predicted rainfall in 13 years and under-predicted it in 11 years. It even failed to predict the drought of 2015 which was successfully predicted by the SSLRF which is broader and provides rainfall forecasts for the four broad geographical regions of India as well as for the country as a whole with a model error of ±8 %.
As on Saturday, the overall rain deficit of the country has come down to 12%, with 17 out of total 36 subdivisions including facing a deficit of up to 60% in the monsoon rains. The rainfall scenario has improved in 14 sub-divisions including Uttar Pradesh and Madhya Pradesh where the rainfall has been recorded to be normal. Five subdivisions have recorded excess rains.