Bay Disturbance to revive Northeast Monsoon

A lot of people have been messaging us about the status of Northeast Monsoon and why we are not putting any post about the possible Low Pressure / Depression / Cyclone that is likely to hit Tamil Nadu in December 1st week.  With active social media fueling the aspirations not to forget the poor performance from Northeast Monsoon so far the expectations are rocketing with each passing day about the likely rains to hit Tamil Nadu.

While we have been monitoring the evolving situation through observations and keeping track of model outputs  we have been biding our time to understand the consistency that evolves among models.  This year thanks to a very fluid atmospheric conditions quite a few times numerical weather models have come a cropper with their estimates even with the expected event less than 120 hours away.  With the models showing threshold consistency for the event to possibly go pretty much on track of how most models estimate we give our inference on how things could evolve this week. We are no experts and have tried to provide an inference based on our understanding of the conditions and model outputs.


Currently the trough of Low is around 4N:92E Latitude to the Southeast of Andaman Islands just straddling the Equator.  Models estimate this disturbance to become a Low Pressure within the next 24 hours. The initial movement could be slightly to the west after which as intensity picks up start climbing latitude in a more NW direction.  With ocean conditions perfectly placed to the East of Sri Lanka it could become a possible depression as it reaches East of Sri Lanka.  While some models estimate the system to intensify further into a possible Cyclone as it nears the coast of Tamil Nadu we feel it could possibly end up as a Depression or possibly a Deep Depression reaching the coast of Tamil Nadu around midnight of 2nd December or may be early morning of 2nd Dec. There could be a more pronounced West movement once again as it nears Tamil Nadu coast with the possibility of a possible W/SW movement not to be ruled out.


It is always difficult to give a rainfall estimate while the event is still a few days away.  Nevertheless with a lot of anxiety around for Northeast Monsoon to bring back the rains we have tried to give an estimate on how the rainfall pattern could evolve after November 30th.  It looks less likely the rains could start before end of day of November 30th for most parts of Tamil Nadu.  As things stand the heaviest rains possibly will happen during the intervening period of 1st & 2nd December.  The time frame could change depending on the movement of the disturbance. Irrespective of the rainfall pattern the Bay disturbance will certainly trigger the life back into Northeast Monsoon in the coming days.

COMK will continue to monitor how things evolve and provide clear and concise inference on what could be expected for Tamil Nadu from the upcoming disturbance.