BHUBANESWAR: A low-pressure area formed over the Bay of Bengal on Saturday evening, triggering speculation over its intensification and possible development into a stronger weather system.
As some models indicated that the low-pressure area might intensify into a storm, the India Meteorological Department (IMD) refrained from issuing any such forecast.
The low-pressure area, which formed at 5.30 pm on Saturday, is likely to move west-northwestwards and intensify gradually into a depression over the east-central Bay of Bengal on September 21 (Monday) before turning into a deep depression over the west-central Bay of Bengal a day later, the national weather forecaster said.
The system is expected to move west-northwestwards and reach the northwest Bay of Bengal near the south Odisha-north Andhra Pradesh coast around Wednesday morning. The deep depression will trigger light to moderate rainfall at many places over the state for four days starting Tuesday. Besides, extremely heavy rainfall may occur on Wednesday and Thursday, while heavy to very heavy rainfall is likely on Friday.
Director of the Bhubaneswar Meteorological Centre Manorama Mohanty said southern districts are likely to witness heavy showers due to the system. She maintained that the system is likely to intensify into a deep depression and that a close watch is being maintained on the atmospheric conditions. Some models suggested that the presence of a westerly trough would restrict the westward movement of the system, which could move up to north Chhattisgarh and then north-northwestwards towards east Uttar Pradesh and adjoining Bihar during the second week.
Other models suggested a low to moderate probability of cyclogenesis during the second week. The IMD CFS (V-2) model indicated a 60-70 per cent probability of cyclogenesis during the first week and a low probability (30-40 per cent) in the subsequent week.
Weather experts said September is typically a transition month rather than the peak cyclone season for the Bay of Bengal, but low-pressure areas and depressions do form in the region during the month.
The daily climatological probability suggests a 13-15 per cent chance of cyclogenesis over the north Indian Ocean. Between 1965 and 2025, 33 depressions, 13 cyclonic storms and six severe cyclones formed over the Bay of Bengal. Formation of a cyclone in September is uncommon because high wind shear usually prevents clouds from growing vertically. Cyclone Gulab, which crossed between the Andhra Pradesh and Odisha coasts on September 26, 2021, was a rare event.