On August 8, heavy rainfall is expected to persist over Jhargram, Bankura, Purulia, Paschim Bardhaman, Paschim Medinipur and Birbhum. (PTI Photo)Written by Arghya ChakravortyA low-pressure area is likely to form over the coastal areas of Gangetic West Bengal and the adjacent northwest Bay of Bengal during the next 24 hours, with the India Meteorological Department (IMD) forecasting heavy to very heavy rainfall over parts of south Bengal and extensive thunderstorms across the state in the coming days.According to the Met, an upper-air cyclonic circulation persists over south Gangetic West Bengal and neighbouring Bangladesh, reaching up to about 7.6 km above mean sea level and leaning southwards, resulting in the likely formation of a low-pressure area during the next 24 hours.The IMD said that the prevailing synoptic conditions are likely to enhance rainfall activity. For south Bengal, IMD warned of heavy to very heavy rainfall (7-20 cm) at one or two places over Purba and Paschim Medinipur and South 24 Parganas districts on Thursday, while heavy rainfall (7-11 cm) is likely over Jhargram, North 24 Parganas, Kolkata, Howrah, Hooghly and Bankura. Thunderstorms accompanied by lightning and gusty surface winds reaching up to 30-40 kmph are also expected.On August 8, heavy rainfall is expected to persist over Jhargram, Bankura, Purulia, Paschim Bardhaman, Paschim Medinipur and Birbhum, accompanied by thunderstorms and gusty wind. Rainfall activity is expected to ease thereafter, thunderstorms are likely to continue through August 10, while isolated heavy rain may continue over parts of South Bengal until August 13.North Bengal is also expected to remain under showers with thunderstorms accompanied by lightning and gusty wind being likely to occur across all districts on August 7, with heavy rainfall forecast over Jalpaiguri, Alipurduar and North Dinajpur on August 8. Heavy rain is expected to spread to Darjeeling, Kalimpong, Cooch Behar and the neighbouring districts on August 9 before gradually weakening.The IMD has warned of lightning strikes, temporary waterlogging in low-lying areas and possible damage to horticultural crops and vegetables in affected districts. People have been advised to remain indoors during thunderstorms and intense rainfall activity.Story continues below this adThe department has also issued a fishermen’s warning. Squally winds of 35-45 kmph, gusting up to 55 kmph, are likely to prevail along and off the state till August 8. Fishermen have been advised against venturing into the sea during this period.Over the past 24 hours, moderate rainfall occurred in parts of south Bengal and at one or two places in the northl. Narayanpur in Birbhum recorded the highest rainfall at 69 mm, while Jiti Tea Estate in Jalpaiguri recorded 30 mm in north Bengal.(Arghya Chakravorty is an intern with The Indian Express)