After two weeks of active and vigorous monsoon conditions it looks like Southwest Monsoon may be heading for a much needed break though rains have already tapered off along the Peninsular West coast. Pasighat in Arunachal Pradesh has recorded more than 12 cms until 5:30 AM today morning which indicates things are shifting towards a Break period with even the monsoon trough slowly climbing up. For the past few days the two circualations on either side was holding the trough south of its normal position while the circulation in the western end of the trough has moved further west reducing in its influence the one on the eastern end has started moving NW and weakening as well reducing its influence also.
If one takes a look at the Intra Seasonal Oscillation forecasts they also pretty much lean to a potentially weak monsoon period for the next couple of weeks. This could mean increased thunderstorm activity over the leeward areas of Penisular India. Interior areas of Tamil Nadu, South AP and adjoining parts of Karnataka may benefit from these thunderstorms. With the overall Westerly regime prevailing coastal areas like Chennai, Delta districts etc would benefit from these interior storms drifting towards the coastline bringing some rains.
Wind charts indicate a weak circulation like feature present off Sri Lanka which is likely to create wind instabilities over many parts of South TN. This is likely to create conducive conditions for afternoon / evening thunderstorms in the region. With UAC like feature pretty much removing upper level westerlies over some parts of TN we may see few places along the Eastern Slopes of Western Ghats come under intense thunderstorms in the dts of Dindigul, Theni, Virudhunagar & Tenkasi.
Chennai and suburbs may benefit from coastal convergence providing support to remnant cells pushing across from interior storms triggering fresh spell of moderate rains later in the night closer to the coast. one or two places may see heavier spell of rains at times in the suburbs.