With Northeast Monsoon remaining subdued in Tamil Nadu with only isolated rainfall activity activity mostly in South Tamil Nadu weather watchers are possibly looking up to the next likely trigger from Bay of Bengal to bring about a change in conditions. Yesterday we had posted about how bad things were on the Northeast Monsoon front using the district rainfall data from IMD. The Rainfall Measurement Mission from NASA pretty much confirms the suppressed Monsoon we have been seeing for the last few weeks.
In particular North Tamil Nadu from Pondicherry upto possibly Nellore in South Andhra Pradesh has possibly seen the highest deficits in the region with the daily rainfall deficit approximately being 10 mm a day.
In the meanwhile the current Trough of Low along the Equatorial Ocean is eagerly watched by weather watchers hoping it brings a change of scenario as far as Northeast Monsoon goes. Models are indicating it to go through marginal development and possibly become a Low Pressure Area in the next day or two with intensity picking up as it comes closer to Sri Lanka.
While in the initial phase it is expected to move in a more East to West direction the likely interaction with the Sri Lankan Landmass is expected to decide the subsequent movement. Models are divergent once the system comes closer to Sri Lanka due to differing estimates of intensity. As things stand Sri Lanka and parts of South TN could get fair bit of rains from this evolving disturbance.
Today also we are likely to see isolated spells of rains continue over South Tamil Nadu and parts of Kerala while one or two places in the Nilgiris Biosphere region could get spell or two of heavy rains. Models indicate possible isolated rains close to Chennai with some luck few areas of the city also could get rains similar to the isolated rains that have about 17 mm to Nungambakkam and 4 mm to Anna Nagar.