Monsoon onset over Kerala may see delay, rain likely to pick up after June 11

THough republic of india Meteorological section (IMD) had calculate a marginally betimes monsoon oncoming, its extended range forecast now shows largely dry conditions over Kerala between May 28 and June 4 and only a very marginal improvement during June 4 to June 11.Rainfall is expected to pick up after June 11, as per the latest ERF (extended range forecast).There are two factors that are likely to cause a delay or a weak monsoon onset over Kerala.There is a typhoon developing over the West Pacific which is seen pulling significant moisture away from the Arabian Sea and Bay of Bengal. There is also a cyclonic circulation over Lakshadweep region which is leading to not much rainfall falling on the land surface over Kerala.Monsoon normally makes its onset over Kerala around June 1. IMD had forecast on May 15 that this year, the southwest monsoon is likely to set in over Kerala on May 26 with a model error of ± 4 days.If after May 10, 60% of the available 14 stations enlisted including Minicoy, Amini, Thiruvananthapuram, Punalur, Kollam, Allapuzha, Kottayam, Kochi, Thrissur, Kozhikode, Thalassery, Kannur, Kudulu and Mangalore report rainfall of 2.5 mm or more for two consecutive days, the onset over Kerala be declared on the second day, provided the depth of westerly winds is maintained and cloudy or overcast conditions continue.Also Read: The long arm of El Nino that suppresses monsoon rains | Number TheoryDuring May 28 to June 3, conditions likely to become favorable for further advance of Southwest Monsoon over the remaining parts of the South Arabian Sea, some parts of extreme south Peninsular India, most parts of Southwest Bay of Bengal, remaining parts of Southeast Bay of Bengal, some more parts of Central Bay of Bengal, some parts of Northeast Bay of Bengal, and Northeast India, IMD has forecast.The prevailing heat wave to severe heat wave conditions is likely to abate from many parts of NorthwestIndia, IMD has forecast on Thursday.Isolated heavy rainfall likely over Northeast and adjoining East India during next 2-3 days and over south peninsular India on Thursday.Moderate to Severe Thunderstorm activity with squally wind speed likely over Northwest India, Central India and East India during till May 31.“There is likely to be a weak onset and not much progress is seen thereafter. Pre monsoon rainfall is there. But no weather system is seen which will carry the surge forward,” said Mahesh Palawat, vice president, climate and meteorology, Skymet Weather.Southwest monsoon has further advanced into some more parts of southwest & southeast Arabian Sea, some parts of Lakshadweep area, some more parts of southwest, southeast and eastcentral Bay of Bengal, remaining parts of Andaman Sea and some parts of westcentral Bay of Bengal on Wednesday, according to IMD.Currently, ENSO-neutral conditions are evolving toward El Niño conditions over the equatorial Pacific. The latest MMCFS (Monsoon Mission Coupled Forecasting System) forecast indicates the development of El Niño conditions during the SW Monsoon season.