Bhubaneswar: The India Meteorological Department (IMD) has indicated in its latest extended range outlook the possibility of a cyclonic circulation developing over the northwest Bay of Bengal towards the end of the first week of July, followed by the formation of a low pressure area over the North Bay of Bengal at the beginning of the second week.
This comes as the southwest monsoon continues its progress over the country, with the seasonal trough playing a key role in rainfall distribution. The system is expected to significantly enhance the southwest monsoon flow across the Indian subcontinent, setting the stage for increased rainfall activity.
According to the outlook, a cyclonic circulation is likely to form over the northwest Bay of Bengal off the Odisha coast around July 2. Under its influence, a low pressure area is expected to develop over the North Bay of Bengal around July 3-4. The system is then likely to move west-northwestwards and become more marked during the second week.
Multiple numerical weather prediction models, including IMD GFS, NCEP GFS, NCMRWF Mithuna, ECMWF, and AI-based models such as Pangu Weather and GraphCast, support this scenario. While deterministic models do not indicate any low pressure area or depression in the next seven days, several models point to the development of the circulation at the end of Week 1 and the low pressure area early in Week 2. Some models suggest the system could intensify further into a marked low or even a depression over the northwest Bay of Bengal around July 5.
No Immediate Cyclogenesis Expected
Importantly, the IMD has assessed that there is no likelihood of cyclogenesis (formation of a depression) during the entire forecast period of the next two weeks. Probability of cyclogenesis remains low (20-30%) in various ensemble forecasts, including those from ECMWF, which is slightly above climatological probability but not indicative of a strong system. The consensus across models shows a large spread regarding the exact location and intensity, but points to a low pressure area rather than a deeper depression.
Implications for Monsoon
The development of this low pressure area could lead to enhanced rainfall activity over parts of eastern and central India as the system moves west-northwestwards. It is also expected to strengthen the monsoon flow over the Bay of Bengal region.
