The trough that has been staying around Sri Lanka has now become a Low Pressure in Bay of Bengal. As things stand though the impact for Chennai could be limited with may be isolated moderate spells at times. Mostly another fairly clear day expected today for Chennai
In the meanwhile yesterday saw fairly widespread rains around the Delta region. Karaikal recorded 51 mm till 11:30 in the night while neighboring Nagappattinam recorded 49 mm till evening. Similarly Cuddalore also recorded 47 mm till 11:30 PM.
Low Pressure in Bay of Bengal Update: With the trough of low now becoming a low pressure in Bay we could expect rains to continue over Coastal Tamil Nadu for the next couple of days or so. It appears as things stand the low pressure is expected to provide widespread rains over Coastal TN. Going by model estimates the region between Pondicherry and Rameswaram is possibly going to see widespread rains with one or two places getting heavy rains. As the low pressure possibly moves in a W/SW direction we could see the impact areas possibly change and will need to be monitored closely if Chennai could continue to get its relief from the rains so that the city can come back to normal. 
Chennai Weather update: Another fairly clear day expected for Chennai with occasional moderate spells of rains like yesterday possibly continuing today as well. This could augur well for the relief works and also allow the waters to recede from most places. Particularly this is going to go a long way in reducing the discharges from the lakes.