It seems that wait for the onset of Monsoon 2019 is getting longer and longer. Earlier, Monsoon was expected to arrive on June 4, four days after its normal date of June 1. However, looking at the sluggish advancement of Monsoon surge, we are now expecting Monsoon to make onset on June 7, with an error margin of +/-2 days.
According to weathermen at Skymet Weather, absence of any strong weather system in Indian Seas led to slowdown of growth of Monsoon surge. After reaching Bay Islands prior to normal date of May 20, Monsoon 2019 became practically stationary for almost a week. By May 27, it covered some more parts of Andaman and Nicobar Islands and by May 30, it had covered significant of portion of Bay of Bengal and Islands including Port Blair. Normally, by May 25, the Northern Limit of Monsoon (NLM) covers both Port Blair as well as Sri Lanka.
Till now, weather conditions have not become conducive for the advancement of Monsoon surge over the Indian landmass. This can be blamed on couple of weather systems which have been restricting flow of westerly winds from reaching Kerala.
As per weathermen, if weather systems are still forming in the Indian sea that means it is not Monsoon air mass. Meteorologically, Monsoon air mass is not conducive for the formation of any cyclone.
However, these weather systems would dissipate during the next 48 hours, paving way for establishment of weather conditions for Monsoon. Also, Madden-Julian Oscillation (MJO) is also coming favourable position. It is at present located in Western Hemisphere in Africa region. Although, forecasters are not at consensus about its movement, but majority indicate that MJO would be moving in east direction towards Indian Ocean, with reasonable amplitude.
With this, there are enough indications of cyclogenesis in Arabian Sea around June 6. A cyclonic circulation is likely to form over Southeast Arabian Sea and adjoining Lakshadweep Islands by that time. As the system gains more strength, it would be setting in pace for all the needed criteria for onset of Monsoon, i.e. required rainfall, wind field and Outgoing Longwave Radiation (OLR).
This system, in particular, would be responsible for the onset of Southwest Monsoon over Kerala. It has full potential of turning into a cyclonic storm, but we need to wait and watch. But if it happens, it would be second cyclone of the season after Cyclone Fani.
However, since the system would be getting more marked and moving away, we do not expect onset to be a strong one. In fact, chances are also there that Monsoon would go silent after the onset.
As the system gets more organized, moist winds would also start concentrating around it. As a result, rains would reduce significantly over Indian landmass. Monsoon rains would only revive once the system moves away from the coast at a sufficient distance.
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Any information taken from here should be credited to skymetweather.com
