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IMD observes a low-pressure area over the Bay of Bengal and a depression over the Arabian Sea
Bay of Bengal system likely to intensify into a cyclonic storm by October 27
Arabian Sea depression not expected to strengthen further, say models
Marine heatwaves across Indian seas could be fuelling storm formation
Experts warn of ecological risks, including coral stress, from rising ocean temperatures
The monsoon may be over, but it has given way to India’s post-monsoon tropical cyclone season. On October 24, 2025, the India Meteorological Department (IMD) observed a low-pressure area in the Bay of Bengal and a depression over the Arabian Sea.
According to the IMD, there is a high probability that the low-pressure system in the Bay of Bengal will intensify into a depression, and possibly a cyclonic storm by October 27 over the southwest Bay region.
While the agency has taken note of the low-pressure system’s potential to develop into a cyclone, the same cannot be said about the meteorological activity in the Arabian Sea. The department noted that “most of the models are indicating north-northeastward movement of the existing depression over the east-central Arabian Sea during the next four to five days”; however, “models are not indicating its further intensification.”
A low-pressure system is an area of lower-than-average air pressure, while a depression is a more developed and intense form of such a system, with a higher probability of transforming into a cyclone.
As of October 24, the IMD reported that the Bay of Bengal low-pressure area was moving at a speed of 10 knots, or just over 18 kilometres per hour (kmph). By the morning of October 27, the depression could reach wind speeds of up to 75 kmph. For context, Amphan — one of India’s deadliest cyclones — reached a peak speed of over 155 kmph when it made landfall.
Another key factor influencing tropical cyclone formation is marine heatwaves, or “periods of persistently and anomalously warm ocean temperatures”, according to the United States’ National Oceanic and Atmospheric Administration.
An analysis of marine heatwave data by Down To Earth indicates that the Arabian Sea, the Indian Ocean and the Bay of Bengal are currently experiencing Category 1, or moderate-level, heatwaves. Apart from triggering cyclonic activity, such heatwaves also have major ecological consequences, including damage to marine life like coral ecosystems.