This year has seen a very sub par winter so far over the southern parts of Peninsular India. Even places in the Deccan Plateau region over Rayalaseema, North Interior Tamil Nadu & South Interior Karnataka have been seeing above average night time temperatures. Around Pongal we had couple of days where the minimum temperatures were seen near normal or slightly below normal.
Invariably its the presence of the land breeze during the post midnight hours that brings about a reduction in night time temperatures in particular to the places along the coast. Wind charts indicate a dip in the pressure line all the way from the Northern parts of Deccan Plateau for the next couple of days. This is likely to bring a fair bit of continental air into Northern TN, in particular over Northern parts of the state.
While Friday promises to see a moderate dip in temperatures compared to Thursday morning Saturday & Sunday could be much cooler with models indicating the northern and western suburbs of Chennai seeing night time minimum temperatures in the region of 17 / 18ºC over the weekend. This spell of cool weather will also be accompanied by overall dryness in atmospheric conditions as well.