West Bengal is set to experience moderate to severe thunderstorm activity over the next four days due to a combination of upper air circulations over the region.
According to the India Meteorological Department (IMD), an upper air cyclonic circulation persists over the northern parts of gangetic West Bengal and its neighbouring areas, extending up to 1.5 km above mean sea level.
A north-south trough now runs from this cyclonic circulation to the north coastal region of Andhra Pradesh via coastal Odisha, located at 0.9 km above mean sea level. Another upper air cyclonic circulation is present over north coastal Odisha at 3.1 km above mean sea level.
These formations, combined with favourable wind patterns and a consistent moisture incursion from the Bay of Bengal, are expected to cause moderate to severe thunderstorm activity in various districts of both South and North Bengal.
The past 24 hours, gusty winds were recorded in isolated areas across several districts of south Bengal including West Burdwan, East Midnapore, North 24 Parganas, South 24 Parganas, East Burdwan, and Nadia.
Wind speeds in these areas ranged between 31 and 50 kilometres per hour.
Rainfall varied from very light to moderate in a few parts of south Bengal, while north Bengal received very light to light rainfall at isolated locations.
For May 4, 2025, the IMD has predicted that thunderstorms accompanied by gusty winds reaching speeds of 50 to 60 kmph, along with lightning and light to moderate rainfall, are very likely to occur in parts of West Burdwan, East Burdwan, Birbhum, and Murshidabad.
Slightly lower wind speeds ranging from 40 to 50 kmph are expected in Nadia, Purulia, Bankura, Jhargram, East Midnapore, West Midnapore, and both North and South 24 Parganas.
Other districts in south Bengal may also see thunderstorm activity, though with wind speeds between 30 and 40 kmph.
On May 5, thunderstorms with wind speeds of 40 to 50 kmph, lightning, and rainfall are likely in Birbhum, East Burdwan, Nadia, and Murshidabad. The rest of south Bengal is expected to experience wind speeds not exceeding 40 kmph.
On May 6, Birbhum, East Burdwan, West Burdwan, Hooghly, Nadia, and Murshidabad are forecast to receive thunderstorms with gusty winds between 40 and 50 kmph.
Similar weather is likely over other districts, though the wind speeds are expected to remain in the 30 to 40 kmph range.
On May 7, thunderstorm activity with wind speeds between 30 and 40 kmph is forecast in North 24 Parganas, South 24 Parganas, East Midnapore, Nadia, and Murshidabad.
The IMD has issued a similar alert for North Bengal.
On May 4, the districts of Malda and South Dinajpur are likely to witness gusty winds touching 50 to 60 kmph, accompanied by lightning and rainfall. The remaining districts are expected to see winds ranging from 40 to 50 kmph.
The weather conditions on May 5 are likely to persist across all districts of North Bengal with wind speeds hovering between 40 and 50 kmph.
On May 6, thunderstorm activity will continue with slightly reduced wind speeds in the range of 30 to 40 kmph across the region.
The IMD has warned about a risk of damage to standing crops, vegetables, and horticultural produce.
Lightning strikes remain a threat, particularly in open fields. Unsecured structures may be vulnerable to gusty winds, and traffic movement could be disrupted in urban areas due to falling branches, waterlogging, or poor visibility.
Residents have been advised to seek shelter in safe locations during thunderstorms, and to avoid taking cover under trees or near electric poles.
Contact with water bodies should also be avoided during periods of lightning activity.