An easterly wave is affecting Central and South TN coast causing rains and thundershowers over there. As we go deeper into the week, the showers would pick up in intensity and rains could reach till Pondicherry and areas farther north due to a northward movement of the trough. Chennai’s chances remain fluctuating. If the trough extends a bit more north, Chennai will experience good thundershowers.
Heavy rainfall is likely to occur from the trough from Thursday-Sunday over coastal parts of S, C TN and parts of N TN as mentioned. Let’s see how Chennai’s chances turn out.
One more interesting thing is the development of a system near Aceh by the 23rd/24th. As of now it is forecast to move towards SL, but it could cause heavy rains over TN.