Last night saw parts of Tamil Nadu get some rains with Villupuram & Tiruvannamalai districts get isolated rains Places like Tirukoilur, Gingee & Mailam recording some moderate spells of rains. Similarly one or two places in Salem district also got some isolated thunderstorms with Vazhapadi recording about 1 cm rains from these thunderstorms. Further down in South Tamil Nadu areas in Pudukottai district got moderate thunderstorms with Devakottai recording 2 cms rains.
The Weak Monsoon current over Peninsular India is pretty much showing in how deep the sea breeze has been moving inland over the last few days. Early part of August saw weak sea breeze with strong Westerlies preventing sea breeze to move inland till may be 9 / 10 PM albeit in a weak form. This week though has seen the roles completely reversed with sea breeze not only setting in the evening around Coastal Tamil Nadu but moving well into the interiors sometimes reaching as much 70 / 80 kms from the coast.
This movement in the process has been triggering thunderstorms around the coastal Tamil Nadu region. Unfortunately due to weak monsoon current remnant moisture that crosses the Peninsular India has been pretty much poor which has resulted in weak thunderstorms and extremely isolated as well. 
Today also sea breeze is expected to move inland around 3 / 4 PM and is expected to be fairly strong as well. This could once again trigger some isolated rains over Tamil Nadu with the delta region once again best placed to enjoy one or two moderate to heavy spells of rains in a few places. There is some chance of rains for North Coastal Tamil Nadu as well though we need to see how things pan out on the wind front with some slight chance of rains for Chennai if the winds turn out right.