While Southwest Monsoon continues to withdraw from the Indian sub continent the eyes are now firmly on the onset of Northeast Monsoon. The retreating monsoon that is the lifeline of Tamil Nadu and Pondicherry is the most anticipated event by the weather bloggers of Chennai. Keeping in mind the importance of Northeast Monsoon we at COMK have tried to provide a simple inference on what could be in store for Tamil Nadu & Pondicherry during this monsoon for this year.
In this context we would also like to mention that we have taken a slightly more holistic approach in terms of the current situation in Tamil Nadu & Pondicherry in terms of the rainfall requirement for the year. This year’s Southwest Monsoon has been very benevolent for Tamil Nadu with many districts recording excess rainfall in particular in the interior areas of the state. With this background we have characterized into four buckets, at one end the safe ones which could possibly end up without much damages even if Northeast Monsoon 2017 was to end as a disaster like 2016. The other side of the spectrum are the ones which require possible a bullet proof Monsoon this year with little room for anything but normal monsoon to end the year on a high.
This inference for Northeast Monsoon 2017 has been done using CFS Long range OLR maps to understand precipitation pattern and possible cyclogenesis in North Indian Ocean. Along with this we have also tried to infer the influence of MJO which in our opinion is the King and the King Maker as far as Northeast Monsoon goes. Years like 2005, 2015 are examples of how constructive MJO could provide a very good monsoon, to the contrary last year saw suppressed MJO influence till 20th of November giving a killer blow to the monsoon prospects. Along with CFS we have also used ECMWF Weeklies to correlate between the two models to understand the consistency in the outcome.
Northeast Monsoon is a volatile monsoon with an extremely short life cycle unlike Southwest Monsoon which runs for more than 4 months. One favorable tropical disturbance could turn the tables completely in a couple of days . As amateur weather bloggers we have tried to provide a honest answer to the Northeast Monsoon puzzle for this year. We honestly believe 2017 could be near normal though an above average monsoon looks less likely.