The trend of evening convective thunderstorms over parts of Tamil Nadu continued yesterday as well with Madurai, Sivagangai & Nagappattinam districts enjoying a fairly good day of rains. Madurai ISRO weather station recorded 63 mm of which 51 mm fell in a span of one hour. Nearby Tirumangalam got about 3 cms rains during the same period. In what is possibly some good news for the delta farmers parts of Nagappattinam and Thanjavur districts got rains with Kumbakonam seeing a stationary thunderstorm dump about 27 mm rains.
Typically during the late season period of Southwest Monsoon one tends to see the Bangalore – Chennai Thunderstorm express. Taking origin around the Kolar / Chickballapur region these thunderstorms then make their journey towards the coast giving rains all along the way until Chennai. Yesterday saw one such express happen very early in the season as a lightning fast thunderstorm express moved from South Interior Karnataka & adjoining parts of Rayalaseema provide some light to moderate rains to Chennai & surrounding areas.
The thunderstorms moved so fast in about 4 hours or so it reached the coast. Though the original thunderstorms moved North of Chennai what it did to help Chennai & its surrounding areas was trigger a fresh set of thunderstorms to the South by interacting with what was a fairly robust sea breeze front that had almost moved inland to about 60 kms or so.
With Yesterday’s low pressure weakening and becoming less influential we could possibly see rains slow down overall in Peninsular India. We could see a weak couple of days before rains pick up once again. On the thunderstorms front for Tamil Nadu we are likely to see another day of convective rains over parts of South Tamil Nadu particularly around the stretch of Madurai / Pudukottai / Sivaganga. Models indicate some weak thunderstorm activity to other coastal areas like Chennai as well triggered by another day of strong sea breeze front