Kolkata: Large parts of West Bengal are set to remain under the grip of thunderstorms, lightning and gusty winds till Friday, with the weather office warning of Kalbaisakhi conditions across several districts.

The intensity and spread of rainfall are expected to peak on Wednesday, before gradually easing towards the weekend.

According to the Alipore Meteorological Department, a cyclonic circulation over Odisha and a low-pressure area over Uttar Pradesh are driving the current weather pattern.

The interaction between these systems is pulling in significant moisture from the Bay of Bengal, triggering the formation of thunderclouds and widespread rain activity.

In South Bengal, scattered thunderstorms are likely across all districts till Thursday, with rain continuing intermittently till Friday.

Districts such as Purulia, East and West Burdwan, Birbhum, Murshidabad, Nadia and North 24 Parganas are expected to witness thunderstorms accompanied by lightning and wind speeds of 50 to 60 kmph.

Kolkata and other districts may see slightly lower wind speeds of 30 to 40 kmph on Tuesday.

The situation is expected to intensify on Wednesday, with Kalbaisakhi storms likely in East and West Burdwan, Birbhum, Bankura, Howrah and Hooghly.

Wind speeds may reach 50 to 60 kmph, along with heavy rain, lightning and the possibility of hail. Thunderstorm activity will persist across South Bengal through Thursday and Friday, though with gradually decreasing intensity.

Dry weather is likely to return over the weekend, pushing temperatures upward again.

North Bengal will also experience weather conditions. On Tuesday, Darjeeling, Kalimpong, Alipurduar, Cooch Behar and Jalpaiguri are likely to receive rainfall with gusty winds of 40 to 50 kmph.

Malda and the two Dinajpur districts may see thunderstorms with winds of 30 to 40 kmph.

Storm activity will intensify on Wednesday across North Bengal, with light to moderate thunderstorms in all districts and Kalbaisakhi conditions likely in Malda and Dakshin Dinajpur, where wind speeds may touch 60 kmph.

Thunderstorms will continue across the region on Thursday, while activity will be largely confined to the hill districts by Friday. Dry conditions are expected over the weekend.

In Kolkata, temperatures dropped significantly following thunderstorms on Monday night, with the minimum settling at 20.2°C, around 5 degrees below normal, and the maximum at 33.6°C.

The city recorded 6 mm of rainfall, with humidity levels ranging between 48 and 95 percent. More thunderstorms are likely in the afternoon or evening through midweek.