NEM 2018 for Tamil Nadu continues to remain an enigma creating a roller coaster of an emotion for not only weather enthusiasts but also common people. If one were to look at the numbers for the sub division of TN & Pondy we have to get more than 50% excess rains in the remaining days of December if TN & PDC has to reach its normal NEM seasonal Average of 44 cms.
The NEM chase card also looks very bad for North TN places like Vellore, Tiruttani, Chennai AP & Chennai Nungambakkam. Both Chennai observatories now need more than 5 times the normal rainfall to reach the annual quota of rains for 2018. It is a different question though whether a burst of such heavy rains in a short time will actually benefit in the long term.
In this context the spell of rains likely to be triggered by the Easterly wave over the next couple of days becomes vital for places like Chennai. As we get into the 2nd week of December the entire equation becomes a lottery for places in North TN. The trough of Low which is aiding the Easterly wave continues to persist over Equatorial Waters and under its influence coastal areas may see rains later today evening. IMD is expecting a possible Low Pressure Area to develop out of this trough of low in a day or two. The disturbance bear Maldives continue to persist which could benefit from the incoming MJO in case it sustains for another couple of days. Will this be a turn of good fortune in strengthening the Easterlies we need to see.
Isolated places in the stretch between Delta & Chennai could see moderate to heavy spells of rains tomorrow early morning. Tomorrow looks a promising day for rains over Coastal areas of TN including Chennai. Looking at how things are as things stand the stretch between Nellore & Puducherry could possibly benefit the most from this upcoming disturbance.