The India Meteorological Department (IMD) Wednesday issued a thunderstorm alert for several districts of West Bengal, both in the northern and southern regions, citing a persistent upper air cyclonic circulation over north Bangladesh and adjoining areas.
The cyclonic system, extending between 1.5 and 5.8 km above mean sea level, has merged with another trough in the westerlies located along longitude 91°E, north of latitude 18°N, which extended between 3.1 and 5.8 km above mean sea level.
This development, coupled with a favourable wind pattern and significant moisture incursion from the Bay of Bengal, is expected to trigger moderate to severe thunderstorm activity across the state over the next few days.
Past 24-hour weather observations
In the past 24 hours, very light to light rainfall occurred at a few places in north Bengal and at isolated locations in south Bengal.
Gusty winds ranging between 30 to 40 kmph were reported at one or two locations across districts of West Bengal.
Tree uprooted at Bakul bagan, Kolkata. (Sourced by The Telegraph)
Thunderstorm, hail, and gusty wind warning for south Bengal
April 30, 2025:
Thunderstorms accompanied by gusty winds reaching speeds of 40-50 kmph, along with lightning and light to moderate rain, are likely to occur at one or two places in Kolkata, Howrah, Hooghly, Nadia, East and West Burdwan, as well as in North and South 24 Parganas.
In the remaining districts of South Bengal, a similar thunderstorm is likely, with lower wind speeds ranging from 30 to 40 kmph.
May 1, 2025:
Thunderstorm activity is forecast to intensify over Purulia, East and West Burdwan, Birbhum, Bankura, Jhargram and West Midnapore.
These areas are expected to experience gusty winds of 40-50 kmph, lightning and light to moderate rain at one or two locations.
Other districts in south Bengal are likely to see thunderstorms with gusty wind speeds between 30 and 40 kmph and lightning at isolated spots.
May 2, 2025:
Thunderstorms with gusty winds reaching 40-50 kmph, lightning and light to moderate rainfall are likely over Purulia, East and West Burdwan, Birbhum, Nadia and Murshidabad districts.
The rest of South Bengal may witness thunderstorms with winds between 30 and 40 kmph and lightning at one or two places.
Thunderstorm and gusty wind warning for north Bengal
April 30, 2025:
Thunderstorms and lightning likely at one or two places in Darjeeling, Jalpaiguri, Kalimpong, Alipurduar and North Dinajpur districts.
May 2, 2025:
A stronger thunderstorm system is forecast over Darjeeling, Jalpaiguri and Kalimpong, where gusty winds of 30-40 kmph, lightning and light to moderate rainfall are likely to occur at isolated locations.
May 3 and 4, 2025:
On both days, thunderstorm activity accompanied by gusty winds (30-40 kmph), lightning, and light to moderate rain is likely to continue in Darjeeling, Jalpaiguri, Kalimpong, Cooch Behar and Alipurduar districts.
Possible impacts of thunderstorms
The India Meteorological Department (IMD) has outlined potential impacts associated with the approaching thunderstorms.
According to the department, damage to standing crops, vegetables, and horticultural produce is expected in some areas.
There is also a heightened risk of lightning strikes, particularly in open fields.
Loose or unsecured structures could sustain damage during periods of gusty winds.
Urban areas may experience disruptions to traffic due to sudden changes in weather conditions, especially during peak storm activity.
Suggested precautionary actions
People are advised to seek shelter in safe locations during thunderstorms and to refrain from taking cover under trees or electric poles.
It is also recommended that individuals avoid contact with water bodies during stormy conditions, as these areas may pose a greater risk of lightning strikes.
The movement of vehicular traffic may be regulated by authorities during periods of severe weather to prevent accidents and maintain order.