Low Pressure in Bay of Bengal but all eyes on Arabian Sea

In possibly what is the opening move towards the onset of Northeast Monsoon 2015 the much anticipated Low Pressure in Bay of Bengal has formed to the East of Sri Lanka.  This low pressure area is expected to kick start our Northeast Monsoon season but in a twist in tale a related development in Arabian Sea is what possibly holds the key to the rainfall prospects over Tamil Nadu. What impact would this have on Northeast Monsoon for Tamil Nadu? More details.

As mentioned in our Yesterday’s Post the development of the Low Pressure Area in Bay of Bengal would be decided by the Tropical disturbance currently lying to the SW of Sri Lanka in the Arabian Sea.  While IMD are expecting the Low Pressure Area in Bay of Bengal to become a “Well Marked Low” within the next 48 hours, the Arabian Sea disturbance is expected to become a Low Pressure within the next 24 hours.

This is likely to create a “Survival of the Fittest” scenario, like to heavy weight boxers sizing up each other the two disturbances are likely to size up each other and possibly pull in the energy from the other, cannibalizing the other for its own survival, and possibly jump start its intensification as well. 
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We could see this continue for another couple of days, while as things stand most models indicate a potential weakening of the Bay system and the strengthening of the Arabian Sea disturbance we feel it is not a straight forward case since the Bay disturbance has the Easterlies strengthening it while the Arabian Sea disturbance could survive only through the cannibalization though to an extent the counter circulation in Southern Hemisphere could aid the Arabian Sea disturbance.  This “Fight to Death” scenario has just begun as weather watchers we have no role to play in this except for observing and interpreting the moves objectively.  Be assured COMK will update you regularly and objectively unbiased.

What impact would this have on the onset of Northeast Monsoon? While it is unlikely to impact the onset of Northeast Monsoon or the schedule there is a fair chance of the rainfall pattern both in terms of how wide spread it could be and how heavy it could be for Tamil Nadu.  And the difference would be as big and Night & Day in case depending on which of the disturbances intensifies.  As things stand rains could start as expected around October 27th for most parts of Coastal Tamil Nadu the quantum of rains is going to depend on all the developments in the intervening period between the two disturbances.  Will the Low Pressure in Bay of Bengal keep up its date with Tamil Nadu or would we have to wait for another day only Nature can answer us.