Under the influence of the Trough of Low coastal areas of Tamil Nadu is seeing light to moderate spells of rains for the past couple of days. Many parts of Chennai recorded rains last night. While the IMD observatory at Nungambakkam recorded 7 mm the Airport observatory recorded 21 mm as southern parts of the city and suburbs witnessed better spells of rains. Further down south both Cuddalore and Pondicherry observatories recorded an identical 16 mm rains till 5:30 AM today.
It is another matter though whether these light to moderate rains will make a difference at all when the overall deficit for TN & PDC stands at 23% with nearly 100 mm still to be received for the Northeast Monsoon season which officially closes by 31st December.
Today and possibly tomorrow though represents the best chance of rains though for Coastal Tamil Nadu. With the Trough of Low now lying partly over the Comorin Sea area we can expect some pick up in steering winds unlike the past couple of days when the thunderstorms struggled to cross the coast line. While this shift in the location of the trough will not drastically alter the probability of rains it certainly improves the possibility for a spell of moderate rains over more areas along the coast and possibly isolated heavy spells in one of two places. Interior areas also could record a spell or two of light to moderate rains.