IMD chief Mrutyunjay Mohapatra said rainfall in August-September was likely to be normal – 94% to 106% of long period average (LPA) – but in the lower end of the range. In August, he said countrywide rainfall is expected to be below-normal at around 92% of LPA.
The forecast indicates normal to above-normal rain in many parts of east and northeast India – where the rain deficit is high – east-central India and most places along the Himalayas. Below-normal rainfall is expected in south India, western parts of northwest and central India, including regions in Maharashtra. Rains in Delhi-NCR could to be normal to below-normal in the two months.
July ended with 13% above normal rainfall during the month in the country, while the overall monsoon performance in the season stood at 5% above normal, IMD said on Monday.
“During August and September, El Nino is likely to become moderate in strength. But the effect could be less severe on the monsoon as we expect a positive Indian Ocean Dipole (IOD) during the remaining part of the rainy season. Rainfall in July was fairly good due to a favourable Madden-Julian Oscillation. But from August 5 till at least around mid-August, MJO may not be so favourable, which could contribute to a reduction in rainfall activity over parts of India during the first half of August.”
Madden-Julian Oscillation is an eastward travelling storm system in the equatorial region that moves across the Indian, Pacific and Atlantic oceans. It brings changes in weather patterns to different areas along its path. During the active phase of the Madden-Julian Oscillation, there is usually more rain than usual in the region it’s passing through.
IMD director general Mrutyunjay Mohapatra said the latest extended range forecast also indicated reduced rainfall activity over central and peninsular India starting from August 5 till August 17, a period when monsoon rain could be deficient. “After that period, rainfall could improve for different parts of the country,” he added.
