From Odisha to Delhi: These states will see heavy rainfall as 2 weather systems merge

India's southwest monsoon has entered one of its most active phases this season, with a deep depression over eastern India combining with an approaching western disturbance to trigger widespread rain, thunderstorms and flood risks across large parts of the country.

The India Meteorological Department (IMD) has issued a red alert for Odisha and Chhattisgarh, where isolated places are expected to receive extremely heavy rainfall, while warning that the weather system will continue to influence central, western and northern India over the coming days.

The deep depression, which originated over the northwest Bay of Bengal, intensified before making landfall along the Odisha-West Bengal coast. It is now moving inland, carrying vast amounts of moisture into the Indian landmass.

At the same time, a western disturbance approaching the western Himalayas is injecting cooler air into the atmosphere. Meteorologists say the interaction between these two systems is expected to intensify rainfall across a wide swathe of the country.

A rare overlap of systems 

A deep depression is among the strongest monsoon weather systems short of a cyclonic storm. Unlike an ordinary low-pressure area, it has a well-organised circulation and stronger winds, enabling it to transport enormous quantities of moisture far inland.

As the system tracks westward, it continues feeding moisture into the monsoon trough, producing prolonged spells of heavy to extremely heavy rainfall over states far from the coastline. The addition of a western disturbance further destabilises the atmosphere, increasing the likelihood of intense rain bands, thunderstorms and localized cloudbursts.

Meteorologists say this rare overlap explains why heavy rainfall is being forecast from the Bay of Bengal coast to the Indo-Gangetic plains and the Himalayan foothills.

Odisha, Chhattisgarh on highest alert 

The IMD has issued a red alert for Odisha and Chhattisgarh, warning of isolated extremely heavy rainfall that could trigger flash floods, waterlogging and landslides in vulnerable areas. Strong winds and rough sea conditions have also prompted authorities to advise fishermen not to venture into the sea.

Several districts in Odisha have already reported heavy rainfall, with rivers and reservoirs witnessing rising inflows. Authorities have issued flash flood warnings in vulnerable districts and advised residents in low-lying areas to remain vigilant.

Rain belt expands across India 

While Odisha and Chhattisgarh remain the epicentre of the weather system, its impact is expected to extend much farther.

Heavy to very heavy rainfall is forecast over Madhya Pradesh, Vidarbha, Jharkhand and adjoining regions as the deep depression moves northwestward and gradually weakens into a low-pressure area. Even after weakening, the system is expected to continue pumping moisture into central India, sustaining widespread rainfall.

North India is also likely to witness an active spell of monsoon rainfall. The IMD has forecast heavy showers over Delhi-NCR, Uttar Pradesh, Uttarakhand, Himachal Pradesh, Punjab, Haryana and parts of Rajasthan as the western disturbance interacts with moisture carried inland by the depression.

The Himalayan states face an elevated risk of landslides, flash floods and road blockages because of already saturated soil conditions and the prospect of continued heavy rain.

Why this monsoon spell is significant 

Unlike many monsoon systems that weaken soon after making landfall, the current deep depression is expected to retain enough strength to influence weather over a large part of the country. Combined with the western disturbance, it is creating a broad corridor of moisture stretching from the Bay of Bengal to northwestern India.

Meteorologists say this interaction will keep the southwest monsoon in an active phase over the next few days. While the widespread rainfall is expected to replenish reservoirs, improve soil moisture and benefit kharif crops, it also raises the risk of flooding, landslides and travel disruptions across several states before conditions gradually improve.