Northeast Monsoon typically has 3 or 4 peaks during the season. The first peak is around the 3rd week of October which often also coincides with the onset. The 2nd peak happens during 1st week of November. This period also has the highest daily rainfall for the season. 4th November to 6th November typically represents the peak of NEM in the daily graph. It is therefore ironic to have a post about convective thunderstorms during peak NEM.
A combination of unfavourable movement of tropical disturbances and overall suppressive atmospheric conditions has created this situation. Nevertheless the cards have been dealt and the game has to continue with the available cards. With anomalous westerlies prevailing since Cyclone Montha the conditions represent pre NEM rather than peak NEM. This has resulted in increased day time temperatures over the plains of TN.
The persisting westerlies have also brought a window of convective thunderstorms over parts of TN. Just like transition season during pre NEM days wind convergence will trigger these storms. Gradually as things settle back to normal and the Easterlies return back over the bay early next week a period of thunderstorms is expected over the plains of TN.
Parts of North TN, adjoining areas of delta districts and pockets of South TN may benefit from these convective thunderstorms. Chennai and suburbs saw isolated thunderstorms over the last couple of days . Yesterday some of the southern suburbs saw moderate to slightly intense thunderstorms. This zone of wind convergence is likely to shift South from today pushing the favourable zone over North TN and adjoining areas of Delta. During this phase Chennai and adjoining North Coastal TN may see subdued rainfall activity.
There appears to be a palpable concern about overall seasonal performance of NEM 2025. The arrival of the monthly forecast from IMD seems to have increased it as well. With almost 5 or 6 weeks of active season ahead there is no reason to worry. A spell of high quality fast bowling in the form of suppression has brought an early innings wobble. NEM 2025 will take a fresh guard after a week or so of slow consolidation from convective thunderstorms.