A cyclonic circulation is marked over extreme western parts of South China Sea, closer to southern parts of Gulf of Thailand. It is likely to become more marked and may become a low pressure area over the same region in the next 24hr. Further, the weather system is expected to come over southern parts of Malay Peninsula and may become a depression over the same area on 16th and 17thDecember. Moving westward, it is likely to shift over northern parts of Strait of Malacca on 18th and 19th December. On the 2nd day, 19thDec, the weather system will be placed in the close proximity of South Andaman Sea and Nicobar Islands.
The low pressure/depression is lying in the equatorial region between 0° and 7°N. Therefore, the system lacks support of ‘Coriolis Force’, very essential for strengthening of weather perturbations. Higher the latitude, more is the magnitude of Coriolis force. Practically, it is zero at equator and negligible between 5°N and 5°S. Accordingly, this weather system is not likely to grow in to any significant system. On the contrary, this will weaken over Strait of Malacca and Malay Peninsula from 20thDecember onward. As a weak low associated with feeble cyclonic circulation, the system will move away from Andaman Sea and head for Gulf of Thailand and adjoining landmass. It is expected to get filled up by 22ndDecember.
Under the influence of this system, Andaman and Nicobar Islands may have heavy rains on 20th and 21stDecember. Rains will not be very intense and continuous, as the islands will be placed at a safe distance from the core area of the system.