Last few days Northeast Monsoon has been fairly active with moderate to heavy rains seen almost on daily basis over some of the coastal areas of Tamil Nadu. Particularly the stretch between Villuppuram district to Nagappattinam district has seen heavy rains almost on daily basis. While Chennai & Suburbs did not see heavy rains on a daily basis but it did see moderate rains daily with isolated places getting heavy rains. The near stationary position of the Low Pressure Area over the Comorin Sea Area was the reason for almost the daily ritual of rains for some of these not only in terms of intensities but also the daily time scales of when rains peaked & dropped.
The Low Pressure Area finally shifted to South Arabian Sea yesterday which is now changing the dynamics after the near constant for the past week or so. This shift in position will bring along with subtle changes in wind pattern which will alter how the rainfall happens over Peninsular India as well. The first change that is likely to happen is a slight reduction in rains over Tamil Nadu which will bring a much needed respite to places in Delta districts that has been seeing continuous heavy rains for the past week.
As the LPA is expected to intensify into a Well Marked Low and continue its journey in a NW direction the influence of this disturbance will reduce over the state by early next week. But we will have to keep a watch on a possible disturbance evolving in South Bay area that could start its cycle of influence over Tamil Nadu. In the meanwhile today due to the slight shift in the LPA & change in wind pattern parts of Peninsular India could come under LWD like conditions bringing possible heavy rains over a few places in North TN, West TN, NW Interior TN & adjoining areas of South Interior Karnataka.
Chennai & suburbs will see intermittent rains in the morning hours with rains peaking once again during the late night hours. One or two places could come under heavy rains at times.
Wishing you & your family a Happy & Prosperous Deepavali.