New Delhi, 29 May

The June-September southwest monsoon seasonal rainfall over India is expected to be 90 per cent of the long-period average with a model error of 4 per cent, the India Meteorological Department said on Friday.

While the Northeast is likely to witness normal rainfall this monsoon season, the remaining parts of the country may see below normal rainfall, the weather office said. The long-period average (LPA) of seasonal rainfall over the country as a whole, based on data from 1971 to 2020, is 87 cm.

LPA refers to the rainfall recorded over a particular region for a given interval, such as a month or season, averaged over a long period of time, typically 30 to 50 years.

Mrutyunjay  Mohapatra, Director General of Meteorology at the India Meteorological Department (IMD), said in a statement, “The southwest monsoon seasonal rainfall over the monsoon core zone consisting of most of the rainfed agriculture areas in the country is most likely to be below normal (less than 94 pc of LPA)."

The average rainfall for the country as a whole in June is most likely to be below normal -- less than 92 pc of the LPA, he said.

If the monsoon season sees less than 90 pc of LPA rainfall, the IMD classifies it as ‘deficient’.

Speaking about the monsoon’s onset over Kerala, Mohapatra said it is expected to happen in the next seven days. Typically, Kerala witnesses the onset of southwest monsoon around 1 June, which marks the beginning of the southwest monsoon season in the country.

The IMD made the observations during its second forecast for the southwest monsoon. On April 13, the weather office had said that India might witness 92 per cent of LPA rainfall this monsoon season.

On Friday, the IMD also said that El Nino conditions are likely to be weak in June, and moderate to strong in September. Currently, neutral El Nino-Southern Oscillation conditions are transitioning towards El Nino conditions over the equatorial Pacific region. The emergence of El Nino conditions leads to less monsoon rainfall in the country.

The weather department also highlighted that in June, above normal monthly maximum temperatures are likely over most parts of the country.

“During June, above normal heatwave days are expected over many parts of Uttar Pradesh, Haryana, Punjab, Bihar, Odisha, Chhattisgarh, Gujarat, and Andhra Pradesh and isolated regions of Maharashtra,” Mohapatra said.

He added that below-normal heatwave days are likely over Rajasthan and Jharkhand.