Andaman Sea has been an active basin during this month. Cyclone Mandous evolved as low pressure area over South Andaman Sea and Southeast Bay of Bengal (BoB) last week, on 06th Dec. Storm had weakened since last weekend and has entered Arabian Sea again, likely to become a low pressure area, very soon. Close on the heels of Mandous, another cyclonic circulation is appearing over the same region, as a prelude to yet another low pressure area.
A cyclonic circulation is marked over Strait of Malacca and Malay Peninsula. This feature is likely to move westward and enter South Andaman Sea in the next 24hr. Circulation is expected to become more marked and may come up as a weak low pressure area over Southeast BoB and South Andaman Sea. Moving further westward, it is likely to shift over South Central and adjoining Southeast BoB on 14th Dec. Weather system is moving rather south in the equatorial latitudes. Therefore, unlike Mandous, it is not likely to intensify and may turn in to a broad cyclonic circulation over South Central BoB and neighbouring equatorial region, on 15th Dec. It is expected to move sluggishly or remain nearly stationary over that area, between 15th and 17th Dec.
An easterly wave is likely to move speedily from the Andaman Sea, across central BoB. This feature will get superimposed over the broad cyclonic circulation around 18th Dec. Moving further westward, the combined influence of these 2 systems will trigger the northeast monsoon activity over Tamil Nadu from 19th Dec onward. This will spill over to other parts of South Peninsula as well, over the subsequent 2-3 days.