North and south India are expected to have below normal monsoon this season, the India Meteorological Department (IMD) said in its forecast Friday. The El-Nino phenomenon, generally believed to have its impact on monsoon, will continue during the rainy season. However, there is a possibility of these conditions to turn neutral during the later part of the rainfall season, the IMD said.
El-Nino is linked to the heating of Pacific waters. Monsoon is likely to be below normal in July and normal in August. “Rainfall over the country as a whole for the 2019 southwest monsoon season is most likely to be normal,” the IMD said. It is likely to be 96 per cent of the long period average (LPA), it said, adding that there is a 41 per cent possibility of a normal monsoon. The LPA over the country as a whole from 1951-2000 is 89 centimeters. Anything between 96-104 per cent of the LPA is normal.
Monsoon is categorised as below normal if the LPA is between 90-96 per cent and classified as deficient, if below that. Anything above 110 per cent of the LPA is classified as excess. Region-wise, the seasonal rainfall is likely to be 94 per cent of LPA over northwest India, 100 per cent of LPA over central India, 97 per cent of LPA over southern peninsula and 91 per cent of LPA over northeast India, all with a model error of plus or minus 8 per cent.
The northwest India sub-division of the IMD covers the entire north India, while the central India subdivision encompasses states like Madhya Pradesh, Maharashtra, Goa, Gujarat and Chhattisgarh. The east and northeast India subdivision covers states of West Bengal, Bihar, Odisha, Jharkhand and the entire northeast, while the southern peninsula covers the five states of the south and the Union Territory of Puducherry.
“The monthly rainfall over the country as whole is likely to be 95 per cent of its LPA during July and 99 per cent of LPA during August both with a model error of plus or minus 9 per cent. “The current weak El Nino conditions over Pacific are likely to continue during the monsoon season with some possibility of these conditions to turn to neutral ENSO conditions during the later part of the monsoon season,” the IMD said.
The monsoon is likely to make onset over Kerala around June 6, five days after its normal onset date. The IMD’s region-wise forecast is in contrast to what private weather forecaster Skymet had predicted earlier this month. Skymet said Central India is likely to receive rainfall of 91 per cent of the LPA and rainfall in Vidarbha, Marathwada, west Madhya Pradesh and Gujarat will be “poorer than normal”.
East and northeast subdivision will get 92 per cent of the LPA and risk remains high for Bihar, Jharkhand and West Bengal, while it will be marginal for Northeast India, Skymet said. Northwest India is likely to receive 96 per cent rainfall of the LPA, while the south peninsula could receive 95 per cent of the LPA, Skymet said. With waters in dams hitting low levels, several parts of Gujarat, Maharashtra, Tamil Nadu are witnessing drought-like situation. If monsoon fails in these areas, that will further aggravate the situation in these states.