Admitting that observational data has showed a trend of decreasing rainfall over the northeast India, the India Meteorological Department (IMD) on Tuesday said, the southwest monsoon seasonal rainfall over the region is likely to be normal.
While announcing the second phase long range forecast for the Southwest Monsoon, IMD director general (meteorology) Mrutyunjay Mohapatra told a media conference: “Monsoon seasonal rainfall over the four homogeneous rainfall region is most likely to be ‘above normal’ for Central India (more than 106 per cent of its Long Period Average (LPA) and South Peninsula (more than 106 per cent of its LPA) while rainfall is most likely to be ‘normal’ over northeast India (96-106 per cent of its LPA) and northwest India (92-108 per cent of its LPA).”
As per this year’s forecast, among the northeastern states, Assam, Arunachal Pradesh, Nagaland would be receiving normal to above normal rainfall while for Mizoram, Tripura and Manipur, the IMD has predicted a possibility of below normal rainfall.
LPA for rainfall is based on observational data from 1971-2020 for the southwest monsoon. It is different for country as a whole and also for the four main homogeneous regions, including the north east India. The LPA for northeast India based on 1971-2020 data is 1,367.3 mm.
In answer to a query about the decreasing rainfall in northeast and whether or not it can be attributed to changing climate, Mohapatra admitted that the IMD has noticed the trend of decreasing rainfall for the northeast based on its observational data.
“However, attribution to causes will need special analysis.”