IMD Issues Second Long-range Forecast Report for Monsoons

India Meteorological Department issued the second stage Long Range Forecast (LRF) for South-West Monsoon Season (June – September) rainfall for the year 2020 at 1415 Hrs today. The Secretary, Ministry of Earth Sciences briefed the press through Online Video Conferencing / Live Streaming from the National Media Centre, New Delhi.  

Highlights of the Report  

• Rainfall over the country as a whole for the 2020 southwest monsoon season (June to September) is most likely to be NORMAL (96% to 104% of long period average (LPA)). 

• Quantitatively, monsoon season rainfall for the country as a whole is likely to be 102% of the LPA with a model error of ±4%. Region wise, the season rainfall is likely to be 107% of LPA over North-West India, 103% of LPA over Central India, 102% of LPA over South Peninsula and 96% of LPA over North-East India, all with a model error of ± 8 %. 

• The monthly rainfall over the country as whole is likely to be 103% of its LPA during July and 97% of LPA during August, both with a model error of ± 9 %. Currently, ENSO Neutral conditions are prevailing over the equatorial Pacific and Neutral IOD conditions are prevailing over the Indian Ocean. 

• Global models are indicating cool ENSO conditions are likely to prevail during the monsoon season with some possibility of development of weak La Niña conditions in the later part of the monsoon season. 

IMD has stated in its other reports that the Southwest monsoon arrived in India has arrived today with heavy rainfall over several places in Kerala. Advance of the southwest monsoon over Indian mainland is marked by monsoon onset over Kerala and is an important indicator characterizing the transition from the hot and dry to rainy season. IMD Director General Mrutyunjay Mohapatra stated that there has been heavy to very heavy rainfall at several places over Kerala. In line with the weather department’s predictions, there has also been a consistent increase in cloudiness and strong winds.  The Met department has issued warning regarding heavy rainfall in the state of Kerala. Thunderstorm with lightning and wind speed reaching 40 kmph in gusts accompanied by moderate rainfall is very likely to occur at in Thiruvananthapuram, Kollam, Ernakulam, Thrissur, Kozhikode, Malappuram, Kasaragod and Kannuras per weather reports. 

Favorable conditions are reported for the onset of the monsoon over Kerala on June 1 due to the formation of Cyclone ''Nisarga'' over Arabian Sea.The monsoon season in the country is between June and September, and contributes roughly three-fourth of the annual rainfall. Majority of the country’s net-sown area does not have adequate irrigation facility and depend mainly on summer season rains therefore update/developments in Monsoons become very essential for the Indian farmers. It its first stage of Long  range forecast the IMD had reported Southwest monsoon rainfall for June to September to be normal or 96-104% of previous year’s rainfall.  

The probability forecasts given by the IMD suggest a very low probability (only 5%) for monsoon rainfall to be deficient. On the other hand, it suggests a very high probability for monsoon rainfall to be normal (41%)  

The latest report also stated that the 2020 monsoon season (June to September) rainfall is likely to be 107% of LPA over North-West India, 103% of LPA over Central India, 102% of LPA over South Peninsula, and 96% of LPA over North-East India, all with a model error of ± 8 %. Thus, monsoon rainfall is expected to be spatially well distributed. The rainfall over the country as a whole is likely to be 103% of its LPA during July and 97% of LPA during August, both with a model error of ± 9.