IMD announced the formation of the Low Pressure Area over the Equatorial waters of South Bay last evening. Along with the announcement of the formation of the Low Pressure Area IMD also gave an alert for heavy to very heavy rains over coastal TN on 3rd & 4th March. Interestingly over the past few days most weather models that have been showing rains for Tamil Nadu on account of this Low Pressure have pushed the rainfall window from 3rd to 5th.
Satellite image shows deep convection over the Equatorial waters south of Andaman and to the E/SE of Sri Lanka. The convection also shows the strong connect the LPA continues to retain with its Cross Equatorial Cousin over the Southern Indian Ocean. This attachment between the two cross equatorial circulations also show why some of the models have been pushing back the rainfall window as movement & intensification of the Bay LPA may be slow until it maintains its connect with the circulation south of Equator.
Though operational outputs of most numerical weather models have indicated the Bay LPA to move towards Sri Lanka / Coastal TN and dump rains over the regions the Ensembles continue to be divided between a potentially Recurve Scenaro that could bring dry weather over Coastal TN in the bargain. So we have two contrasting scenarios with extremely contrasting results. While the operational outputs of ECMWF, GFS, ICON etc have leaned towards heavy rains over Coastal TN influenced by the NW track of the disturbance towards Sri Lanka / Coastal TN models like GEM have been consistently looking at NNE track towards Central Bay without much impact for TN. It is interesting to note a couple of weeks when a possible LPA was expected to come towards Coastal TN by ECMWF / GFS it was GEM which picked up first the trend of that disturbance staying in East Bay without impacting TN.
Given the contrasting scenarios we at COMK have decided to raise our hands and leave it to Nature to evolve as it wants. Though some may feel we are fence sitting but to be honest we are not equipped enough to take a clear call either ways.