The last few days have seen most of Tamil Nadu record warmer than normal temperatures as Northeast Monsoon continues to be in a subdued phase. A combination of clearer skies and lack of moisture at lower & middle levels of atmosphere has meant the day time temperatures have been staying high. Both the Chennai observatories have been recording well above normal temperatures since Nov. 15th.
Similar trend is expected to prevail for the next couple of days as currently the Low Pressure in Bay of Bengal near Andaman Sea has meant the moist low level Easterlies dont reach coastal Tamil Nadu. Instead we see the dry continental wind from North pushing into the coastal areas. Not only does the low level moist Easterlies bring in the rains they also act as an insulation keeping temperatures under check.
As the low moves further West towards the coasts of Tamil Nadu / Sri Lanka the low level winds will become Easterlies bringing in the moisture from Bay and along with it the rains as well. While there is divergence on how the current low near Andaman finally ends up there seems to be a sync though this could either trigger a fresh pulse or possibly regenerate as a stronger system while it reaches the warm Equatorial waters East of Sri Lanka.
Depending on which of the option evolves the overall rainfall calendar could shuffle around by about a day or two starting from 26th / 27th Nov. Till then we will possibly see fair weather with above normal day time conditions.