Orange alerts issued as Bay of Bengal system threatens eastern India with heavy rain

What is causing the heavy rain alerts?

The India Meteorological Department has issued orange alerts for Odisha, Chhattisgarh, and Coastal Andhra Pradesh, warning of severe downpours that could trigger localised flooding and disrupt transport networks. The heavy rainfall is being driven by a persistent low-pressure system over the Bay of Bengal, which meteorological authorities expect to strengthen as it moves inland.

The system is currently sitting over the northwest Bay of Bengal, close to the coasts of southern Odisha and northern Andhra Pradesh. Over the next 24 hours, it is projected to move west-northwest across these coastal regions, bringing heavy to very heavy rain. The system's associated cyclonic circulation extends nearly nine kilometres into the atmosphere, anchoring a monsoon trough that stretches across northern and central India.

Which areas are most affected?

Under the orange alert, isolated areas in Odisha, Chhattisgarh, and Coastal Andhra Pradesh could receive between 115.6 mm and 204.4 mm of rain. Authorities have warned residents in low-lying areas of potential waterlogging and inundation. Farmers have been advised to secure drainage for their fields and stay indoors during storms.

The weather system's impact stretches far beyond the coast. The meteorological department has also issued yellow alerts for several other states, including Madhya Pradesh, Jharkhand, Telangana, Kerala, and parts of the Northeast, where rainfall between 64.5 mm and 115.5 mm is expected. In Uttarakhand, where heavy rain is forecast to continue, yellow alerts are active for mountainous districts such as Dehradun, Nainital, and Chamoli, raising fears of landslides and rising river levels.

What are the expected wind speeds and other hazards?

In addition to the rain, high winds are expected to lash several regions. Coastal Andhra Pradesh is bracing for thundersqualls with wind speeds of 50 to 60 kmph, gusting up to 70 kmph. Winds of 40 to 50 kmph are expected in Tamil Nadu, Puducherry, and Vidarbha, while lighter but still disruptive gusts of 30 to 40 kmph are forecast for Bihar, Jharkhand, and West Bengal.

The weather system has already made its presence felt. In the 24 hours leading up to Thursday morning, Kaiserganj in Uttar Pradesh recorded 13 cm of rain, while Banki in Odisha received 10 cm. Even Delhi, further from the core of the system, is expecting a cloudy outlook with light rain and gusty winds of up to 40 kmph, offering a brief reprieve from daytime temperatures.