Notwithstanding its differences with Indian Meteorological Department (IMD), Skymet, the first private sector weather forecaster since 2003, has observed that the monsoon currents from the Bay of Bengal are gradually shifting their positions towards central India, causing more rain in Madhya Pradesh, Chhattisgarh, Odisha, and Andhra Pradesh, thereby depriving Punjab, Haryana and Delhi of its normal share. This deflection of monsoon currents may be due to climate change, felt Skymet's chief Meteorologist Mahesh Palawat.
The IMD conceding that though the rains in North-west have diminished over the past three years, the shifting of monsoon currents from the Bay of Bengal towards central India is yet to be established.
The contention of Skymet that the rains in the North-western plains — comprising Punjab, Haryana, Delhi and Rajasthan — have gradually reduced for the past three years has been substantiated in the three-year consecutive data. While the rains were 686.8 millimetres (mm) in 2010, it got reduced to 654.8 mm in 2011 and further dipped to 569 mm in 2012.
The scenario in 2013 is not expected to improve either. The IMD in its second stage of forecast has already predicted that south-west monsoon over much of North-West India is likely to be below normal at 94 per cent of the long-period average.
However, given the above data, its interpretations by the two respective weather agencies differ. Palawat said the monsoon currents from the Bay of Bengal are showing definite indications of changing their conventional path, causing higher rainfall over the Telangana region of Andhra Pradesh, and parts of Central India, leaving States — Punjab Haryana and Delhi — drier.
The weather scientists from IMD, however, pointed out that this drop in rains in North-West is within the normal range and is no cause for worry. North-West India gets its rainfall from monsoon currents emanating from both the Arabian Sea as well as the Bay of Bengal.
The experts, however, did not rule out the impact of climate change affecting the south-west monsoons in the country. The weather is already turning erratic in the country, due to rising by global warming. The flash floods in Uttarakhand earlier and presently in Imphal may be attributed to such factors. Further, this is also likely to make the day-to-day rainfall in the country more variable and thereby increasingly difficult to predict. Even if the seasonal mean precipitation may remain unchanged the impacts none the less could be substantial, they added.