For the last few days Rains have been making its presence in many places of South India. South Tamil Nadu saw good rains on Tuesday night, Kerala has been seeing good rains for the last 3 days. Yesterday saw South Interior Karnataka get heavy spells of rains in a few places with even parts of Bengaluru catching up a good spell or two. Along with this some parts of West Interior Tamil Nadu also got some rains around Coimbatore area.
Today we could see the thunderstorms shift further to the East bringing two areas which have hardly seen any activity so far. South Andhra Pradesh & North Tamil Nadu. The area to the West / Northwest of Chennai is going to be the hot spot in terms of the Zone of Instability deriving out of the Wind Convergence. As the moist Westerly winds aided by the Low Pressure Area move across the Inland area it will interact with the different mass air particles created by the Day Time Heating. When the Westerlies meet the more drier Easterlies, an effect of the outflow from the HPA over Bay, a highly unstable atmospheric conditions is likely to be created over the Interior areas.
What we are likely to see is an early dress rehearsal of the typical Southwest Monsoon Thunderstorms that happen later in the year. Westerlies bringing the moisture over land with Day Time Heating creating conducive environment for convection to build up creating evening thunderstorms. If one were to look at the hot spot it is easy to relate the role the broken Eastern Ghats will be playing in the development of these thunderstorms.
All in all it points out to be a blockbuster Friday Release for Rayalaseema, South Int, Karnataka, South Coastal Andhra Pradesh & North Interior Tamil Nadu with isolated places likely to see heavy thunderstorms light up the skies. As far as Chennai goes we are still unable to stick our neck out and make a firm estimate.