An upper air cyclonic circulation is expected to form over the North Andaman Sea around Sunday, likely leading to a low-pressure area over the Central Bay of Bengal by October 22. This system is projected to move northwest and could intensify into a depression by Tuesday, with further potential to develop into a cyclone, according to the Regional Meteorological Centre (RMC).

While showers are anticipated in South Bengal and Kolkata, it’s too early to determine if heavy rainfall will occur. The RMC bulletin on Friday mentioned that this depression could cause light to moderate rain in many areas, with isolated heavy rain on Wednesday and Thursday. Fishermen are advised to avoid venturing into deep sea areas in the central and southern Bay of Bengal on October 22 and 23.

Cyclonic circulation expected to form over North Andaman Sea, potentially intensifying into a cyclone

According to the India Meteorological Department (IMD), a fresh upper-air cyclonic circulation is expected to develop over the North Andaman Sea around October 20. This is likely to result in the formation of a low-pressure area over the central Bay of Bengal by October 22, which could move northwest and intensify further, said Manorama Mohanty, Director of IMD Bhubaneswar. Odisha may experience rainfall from October 23 to 25 due to this system, although it is still too early to confirm the development of a cyclone. The IMD is closely monitoring the situation and will provide daily updates.

In its latest weather bulletin, the IMD predicted widespread rainfall over Kerala, Lakshadweep, and Karnataka, and scattered to widespread rainfall across Tamil Nadu, Puducherry, Karaikal, Coastal Andhra Pradesh, Yanam, Rayalaseema, and Telangana this week. Isolated heavy rains are expected in Tamil Nadu, Puducherry, and Karaikal on October 18, 20, and 21, in South Interior Karnataka between October 17 and 22, and in Kerala and Mahe on October 17, 22, and 23. Heavy rains are also forecasted for Coastal Andhra Pradesh, Yanam, Rayalaseema, and parts of Karnataka on October 17.

Earlier this week, two consecutive depressions formed over the Central Arabian Sea (October 13-15) and the Southwest Bay of Bengal (October 15-17) during the southwest monsoon withdrawal. The second depression crossed the north Tamil Nadu-South Andhra Pradesh coasts on October 17 before weakening. These systems brought heavy rains to Tamil Nadu, Andhra Pradesh, and Karnataka, with significant downpours in Chennai on October 15. Rainfall also affected South Coastal Andhra Pradesh and Rayalaseema from October 14 to 17. Moderate rainfall is expected over Konkan, Goa, and central Maharashtra in the next five days.