After what was a poor season summer rains in Tamil Nadu has picked pace over the last few days with regular rains happening over the interior places under the influence of the Wind Discontinuity. The firm presence of Wind Discontinuity over Peninsular India is the indication of the changing season as the Indian sub continent gets ready for the Southwest Monsoon. While parts of the interior South India is slowly getting into the Westerly winds the East coast continues to see Easterly winds. It is at the point where the Easterly & Westerly winds meet that triggers the necessary instability for thunderstorms to form aided by the day time heating.
Today also Summer rains in Tamil Nadu is set to continue over the interior regions particularly around Coimbatore / Erode / Sathyamangalam region. Models indicate some moisture incursion from the East during the early part of the day over Northern Tamil Nadu which could bring in some stray showers over parts of Greater Chennai region and adjoining Tiruvallur / Kanchipuram regions. There is some chance of rains for Vellore district during late evening / night. 
Temperatures in the interiors are expected to say around 40 degrees or lower across most places as cloudy conditions could keep a check on the temperatures with late afternoon / evening thunderstorms expected in the Western parts of the state bringing down the temperature as well.
