A New System is Brewing
The India Meteorological Department (IMD) has indicated that a fresh cyclonic circulation is forming over the west-central and adjoining northwest Bay of Bengal. Forecasters anticipate that this system will intensify into a low-pressure area around September
11. Such systems are significant drivers of monsoon rainfall, acting like engines that pull moisture-laden winds from the sea over the Indian subcontinent. This development comes after a period of relatively subdued rainfall activity, particularly over peninsular India, prompting questions about whether the monsoon season was ending prematurely.
Which States Are on Alert?
The primary impact of this new system is expected to be felt across eastern, central, and northeastern India. The IMD has issued alerts for heavy rainfall in several states. Odisha and the coastal areas of Andhra Pradesh are on watch as the system forms off their coasts. As it moves inland, states like West Bengal, Jharkhand, Chhattisgarh, and eastern Madhya Pradesh are expected to receive fairly widespread rain. Forecasts predict heavy showers for Odisha and Chhattisgarh from September 10 to 12. The northeastern states, including Arunachal Pradesh, Assam, and Meghalaya, which have been witnessing an active monsoon phase, will also likely see continued rainfall.
Delaying the Monsoon's Retreat
The arrival of a new low-pressure system interrupts the natural withdrawal process of the monsoon. The formal retreat typically begins from northwest India around mid-September, marked by at least five consecutive days of no significant rainfall and a change in wind patterns. While satellite imagery has recently shown clearer skies over parts of northwest India, indicating a weakening of the monsoon flow there, this new system will keep conditions ripe for rain in other regions. This push of moisture will likely delay the establishment of an 'anticyclone'—a high-pressure system that signals the end of the rainy season—over the subcontinent. Weather models now suggest a more organised withdrawal may only begin in the second half of September.
An Uneven Season Overall
This late-season surge comes at the end of a monsoon that has been erratic and uneven. While some pre-monsoon forecasts for 2026 suggested a below-normal season due to developing El Niño conditions, the actual distribution has been highly varied. As of early September, the country as a whole faced a rainfall deficit, though this masks significant regional differences. Large parts of southern and northeastern India have recorded below-normal rainfall, while some other areas have seen surpluses. Meteorologists have pointed to a pattern of prolonged dry spells broken by intense, short bursts of heavy rain, a trend that makes the season's performance difficult to assess by averages alone.
What to Expect Next
For the next week, while peninsular India might remain relatively dry, residents in central and eastern states should prepare for wet conditions. Heavy rainfall warnings are in effect for parts of West Bengal, Odisha, Chhattisgarh, and Madhya Pradesh through September 12. Authorities in Odisha have been alerted, with the IMD issuing specific warnings for thunderstorms and gusty winds in several districts even before the low-pressure system fully forms. This spell of September rain is crucial, particularly for agriculture, as it helps maintain soil moisture for the upcoming winter cropping season. The progress and intensity of this Bay of Bengal system will be closely monitored over the coming days to determine its full impact.
