The deep depression over the Southwest Bay of Bengal was struggling to intensify into a storm, yesterday. However, the system was battling against too many odds and finally succumbed to an overall unfavourable environment. The deep depression may retain its intensity till late tonight and drop grade thereafter. In all probabilities, the system will cross the Tamil Nadu coast as a depression, sometime tomorrow morning.
The deep depression is now centred around 10.5°N and 82.6°E over Southwest Bay, off the Northeast coast of Sri Lanka. It is located almost east abeam Nagappattinam by 300 km and nearly 400 km southeast of Chennai. It will move northwestward, steadily and slowly, to reach in the close proximity to the coastline tomorrow morning. The deep depression is placed in a marginal environment, unlikely to support any further intensification.
The sea surface temperature still remains favourable (28°-29°C) but drops as it moves close to the coastline. The tropical storm heat potential is dropping to under 50 KJ/sq cm. The vertical wind shear is high and is offsetting the conducive surface temperatures. For sustenance and growth of the system, the entire column of the storm needs to remain aligned. Any asymmetrical distribution of wind field becomes detrimental to its intensity.
The deep depression will come dangerously close to the coastline of Tamil Nadu, in the wee hours of tomorrow. Even, the depression has a fairly strong field of convective clouds and churning winds. The depression may cross the coast close to Puducherry-Karaikal and weaken over land. The coastal stations like Puducherry, Karaikal, Nagappattinam, Cuddalore and Tondi will be at risk of inclement weather conditions. The combination of strong winds and incessant heavy rains is the most destructive aspect of such systems. The capital city Chennai will be slightly on the outer peripherals of the system. Yet, locations like Mahabalipuram, Kancheepuram, Tambram, Meenambakkam and Nungambakkam will also observe a few spells of adverse weather conditions. Interiors of Tamil Nadu, Rayalaseema and South Interior Karnataka will also receive moderate to heavy rain and thundershowers. The system, after weakening may lash parts of Kerala and cross over to the Arabian Sea, as a low-pressure area.