It is always a tough call when to alert and how much to alert. During Cyclone Fengal as the models aligned tighter on a possible stall it became essential to raise the alert about the risks. The experience of a complex event like Cyclone Fengal is always in the back of the mind during subsequent events too. Parts of North Coastal TN still recovering from Fengal while South TN recovering from its own heavy rainfall event few days back. It is always possible one tends to panic with any new development. As communicators it becomes essential to alert with a fine balance that allows people to be prepared.
Over the past 24 hours there has been more clarity on how the expected Low Pressure in Bay may behave. While it continues to struggle against unfavourable factors it is essential to point out rains were the biggest threat always from this system. With complex dynamics involved the question of “How early is early?” always crops up. With the expected event now not too far away it is essential to provide an update on what to expect.
There is very less chance of this cyclonic circulation to consolidate into a Depression or a Cyclone.It is likely to complete its life cycle mostly as an LPA or a Well Marked Low. The cyclonic circulation is expected to become an LPA today and will continue to move west for the next 24 hours. From tomorrow it is likely to move in a more Northward movement towards North Coastal Tamil Nadu. There is very less chance of the LPA / WML moving further west once it reaches off the coast of North Coastal TN due to the presence of a ridge. At this point the LPA could either dissipate in the open seas or get pulled NE by the Westerly trough that is likely to strengthen around 19th December.
Keeping in mind the current conditions and increasing alignment among weather models here are the Key take aways for the next couple of days. As always with weather the inferences are always based on probability.
- Rains for Coastal TN is likely to start from tomorrow morning. Initially delta coast may see rains first, gradually the rainfall zone will climb up.
- Except for the stretch between Chidambaram and Nellore rest of the areas need not worry about heavy rains.
- Interior areas of Peninsular India may see at best light to moderate rains
- South TN may see at best light rains allowing relief and recovery to continue.
- The stretch between Mahabalipuram and Sriharikota may need to be alert for very heavy rains.
- The convex coast of KTCC districts brings a 50% chance for extremely heavy rains over one or two places.
- The rainfall event will roughly prevail for about 24 hours from the time it starts
- The stretch between Marakkanam and Sriharikota may alone see the rainfall event stretch to about 30 to 36 hours depending on the movement of LPA / WML