Well marked low pressure over Bay of Bengal (BoB) has intensified in to a depression today morning. Depression is centered around 9.4°N and 86.4°E, gaining a latitude of 2° and westward drift of about 300km, in the past 24hr. It is located around 800km southeast of Chennai and nearly 1000km from Machilipatnam. It is likely to maintain same track for the next 24hours, intensify to a deep depression and move over southwest BoB.
The satellite imagery with fine resolution is showing fragmented curved banding with signs of consolidation. Deep convection wrapped around the broad low level cyclonic circulation has grown in coverage. Apparently, the presence of Madden-Julian Oscillation has triggered large convection and enhanced outward flow. Environmental conditions remain favourable, like the last two days. Low vertical wind shear, warm sea surface temperature and least entrainment support its intensification to a tropical storm. While the system moves steadily northwest with gradual consolidation, the potential for upgradation to a cyclone in the next 24 hours is increased to ‘medium’ and ‘high’ in the next 36-48hr.
Numerical models still differ in predicting track, timelines and intensity. There is consensus for development of a storm but dichotomy remains regarding strength and landfall. With the realistic assumption of this weather system gaining latitude of 3° in 24 hours, the consistent northwestward movement will bring it closer to South Coastal Andhra Pradesh. North Tamil Nadu coast from Puducherry & Chennai and Nellore, Kavali, Ongole, Bapatla, Machilipatnam and Kakinada of Coastal Andhra Pradesh fall within the striking distance of the storm. The curved and northeast-southwest oriented coastline of Andhra Pradesh may restrict its sea travel. Therefore, the cyclone may make landfall between Nellore and Kakinada on 04thDecember 2023. Confidence of this forecast is not very high and will be revisited in the next 24hours. Likely intensity and the landfall timings will need further deliberations.
The outer bands of the storm will reach the coast of Tamil Nadu on 2nd December and the core of storm close in further on 03rdDec. Active northeast monsoon conditions will lash Tamil Nadu with scattered moderate to heavy rainfall on 01st and 02nd Dec. The storm will invade north Tamil Nadu and Coastal Andhra Pradesh with heavy to very heavy rains on 03rd and 04th Dec. Squally winds, pouring rains, lightning & thunderstorms may give a scary look all along the coast of these two states. Sea condition will be extremely rough and utmost precautionary measures will be needed for off shore activities and sea born platforms, if any.