The last few days saw rains in Tamil Nadu come to almost a stand still as a suppressed phase of Northeast Monsoon since the Depression in bay moved North holds firm grip. Yesterday saw some rains in parts of South Tamil Nadu in particular along the Western Ghats. This hopefully is the start of a fresh spell of rainfall activity over Tamil Nadu as slowly the Easterlies pick up in the days to come.
This weak phase of NEM is showing in the daily rainfall graph as well which has been only seeing negligible improvements over the last week or so. Yesterday the daily rainfall reported no place recording at least 10 mm. This is the second instance where no place in Tamil Nadu & Pondy recorded at least 10 mm after 25th Nov.
Thanks to the weak Easterlies, parts of South TN & South Kerala is under the influence of pseudo Westerlies. This pseudo Westerlies at lower levels of atmosphere though is going to be a savior providing rainfall opportunities for Tamil Nadu today. Interior districts of Tamil Nadu is likely to see a Line of Wind Discontinuity develop later in the day as Westerlies & Easterlies meeting along the Western Ghats creating an unstable atmospheric condition.
This is likely to provide thunderstorm opportunities in the interior districts and along the Western Ghats. The situation is almost like Pre & Post Monsoon seasonal wind change period that gives some of the most intense thunderstorms for interior areas. Since the Westerlies are weak we may not see very intense thunderstorms but moderate rains are likely. With some luck Kongu belt could catch up with a shower or two.
It is indeed an irony that during NEM we are possibly giving possible rainfall expectations in interiors and expecting nearly nothing for coastal areas. Vagaries of Weather Possibly.