As the remnant circulation of Cyclonic Storm Fengal continues its slow journey across Peninsular India large parts of Tamil Nadu remain battered. While Pondicherry was battered on Saturday night, Villupuram was battered for nearly 24 hours from Saturday afternoon to Sunday afternoon. Tiruvannamalai like Villupuram saw extreme rains continue for more than 24 hours from Saturday late night to Sunday late night. As the circulation moved west slowly Krishnagiri and Dharmapuri districts got battered by extreme rains last night. When most people were giving up hopes on NEM 2024 it has marked its presence in the most violent way. The TNSDMA observatory at Villupuram has recorded 1198 mm so far this NEM 2024 which is the highest among all the TNSDMA stations in the plains.
While the focus is on relief and rehabilitation from the flooding events that is unfolding over parts of TN it is also essential not to miss our focus on what is likely to be ahead of us. Looking slightly ahead always comes with an uncertainty that is part of weather dynamics. In our post on 30th October one of the highlighted period was last week of November. The sub seasonal ensembles were picking up the last week disturbance consistently. Eventually it ended up creating one of the worst rainfall events of NEM 2024.
Today’s post is aimed at being ready and with a caveat long term weather forecasts come with a high degree of uncertainty. There is a very high chance NEM 2024 will continue to remain active during most of December due to favourable dynamics as explained in the charts. While there could be a lull in rains over the next few days once the current Fengal remnant moves into Arabian Sea, things are expected to pick up again next week. There is a high chance we may see the 3rd cyclone of NEM 2024 around mid December. There is though uncertainty on impact zone and impact potential. The Key take aways are as follows.
- The remnant of Cyclonic Storm Fengal will continue to move across Peninsular India eventually continuing its journey as a WML / Depression over Arabian Sea.
- This could bring heavy rains over the next couple of days over Western parts of Peninsular India including interior TN and interior Karnataka
- Coastal areas of TN may see moderate rains continue for next couple of days due to moisture drag created by the Well Marked Low
- While MJO is present over Maritime Continent it is likely to provide regular movement of Cyclonic Circulations into Bay of Bengal from South China Sea.
- Sub seasonal ensembles indicate Bay of Bengal may throw up another 2 Low Pressure systems during December.
- There is a 50:50 possibility one of these couldintensify into a Cyclone during mid December. The period between 14th to 20th December should be watched out for potential cyclone developing over South Bay. Though it remains to be seen where the impact area could be.
- While the upcoming week may see lesser rains over Coastal areas of TN consequent to the Fengal remnant moving into Arabian Sea the period between 9th to 23rd December may see above average rainfall activity leading to active monsoon conditions continuing well into December.
On the immediate weather front while Coastal Tamil Nadu gets much needed relief today from rains. Interior areas of TN will continue to see rains for another day or two as the WML moves across slowly. Parts of South interior Karnataka and North Kerala will see heavy to very heavy rains as the circulation nears Arabian Sea. Subsequently we may see a lull in rains though a complete cessation of rains is less likely.