The southwest monsoon may be showing signs of retreat, but the season could still have another major spell of rainfall in store for India.
According to emerging weather model projections, a depression or potentially a stronger tropical system could form over the Bay of Bengal between September 24 and 28. If the system develops as currently indicated, it could trigger widespread rain across parts of eastern and central India during the final phase of the monsoon season.
However, meteorologists are maintaining caution at this stage. The system has not yet formed, and its eventual strength, movement and rainfall impact remain uncertain.
Bay of Bengal System Could Bring Widespread Rain
Current forecast models indicate that a weather system could emerge over the Bay of Bengal and initially travel northwestward toward Odisha.
From there, it may move across areas of south Chhattisgarh and Bihar before potentially changing direction toward Northeast India.
Such a track could bring rainfall to a large area, particularly across eastern and northeastern parts of the country. Depending on how the system develops, central India could also experience another round of significant monsoon showers.
The latest Artificial Intelligence Forecasting System (AIFS) projection for September 26 depicts a well-marked low-pressure area over the region, along with an extensive zone of rainfall.
The model currently indicates the possibility of heavy to intense rain close to the system’s centre. However, this forecast could change significantly as the potential weather system gets closer.
Forecast Uncertainty Remains High
Weather experts have warned against drawing firm conclusions from forecasts this far in advance.
Tropical systems forming over the Bay of Bengal can change rapidly. Small variations in atmospheric conditions can influence their intensity, direction and landfall location.
As a result, the projected track could shift considerably over the coming days. A more reliable picture is expected once the system begins to develop and observations become available.
Northwest India Could Turn Drier
While eastern and northeastern India may experience renewed monsoon activity later in September, northwest India could move in the opposite direction.
Forecasts indicate that a large anticyclonic circulation may develop over northwest India after September 25, potentially extending into the northern Arabian Sea.
An anticyclone generally promotes more stable and dry weather. Its development could therefore support drier conditions across northwest, western and parts of central India while also helping the southwest monsoon withdraw from these regions.
Monsoon Withdrawal May Begin From Rajasthan
The first major signs of the seasonal retreat could emerge over northwest Rajasthan between September 15 and 18.
If conditions remain favourable, the withdrawal could gradually progress across other parts of northwest and western India.
This means the country could see two contrasting weather patterns during the latter half of September: the monsoon beginning its retreat over northwest India while another weather system potentially revives rainfall over eastern and northeastern regions.
Monsoon Could Deliver One More Big Rain Spell
The southwest monsoon may therefore not be finished just yet.
Although its withdrawal could begin soon over parts of northwest India, the possible development of a Bay of Bengal system between September 24 and 28 could provide one final significant burst of monsoon rainfall across several parts of the country.
For now, the exact impact will depend on whether the system develops and, if it does, the track and intensity it eventually takes. More clarity should emerge as September progresses and the weather system gets closer to formation.