Bay of Bengal Depression Triggers Heavy Rain and Thunderstorm Alerts Across West Bengal
A depression over the northwest Bay of Bengal has intensified monsoon activity across West Bengal, prompting the India Meteorological Department (IMD) to issue heavy rainfall and thunderstorm warnings for large parts of the state over the next two days. While coastal and western districts of South Bengal are expected to receive the heaviest rain on Sunday and Monday, rainfall activity is likely to intensify across North Bengal from Monday onward.
According to the Regional Meteorological Centre (RMC), Kolkata, the depression was centred over the northwest Bay of Bengal near the Odisha–West Bengal coast on Sunday morning, around 50 km south-southeast of Balasore and about 60 km south-southwest of Digha. The system is expected to move west-northwestwards and cross the north Odisha coast between Chandbali and Digha within the next 24 hours before weakening over land. Under its influence, widespread rainfall and thunderstorm activity are expected to continue across the state through the week.
For Kolkata, the IMD has forecast a generally cloudy sky with a few spells of rain or thundershowers over the next 24 hours. The maximum and minimum temperatures are likely to remain around 30 degrees Celsius and 25 degrees Celsius, respectively. Alipore recorded a maximum temperature of 33 degrees Celsius, 0.4 degrees above normal, and a minimum of 27.4 degrees Celsius, 0.6 degrees above normal. Relative humidity ranged between 69 per cent and 94 per cent. The city received 2.6 mm of rainfall during the 24 hours ending at 11.30 am on Sunday, with another 2.3 mm recorded after 8.30 am.
The IMD has warned of heavy rain (7-11 cm) at isolated places over Kolkata, Howrah, South 24 Parganas, Bankura and Purulia on Sunday. Thunderstorms accompanied by lightning and gusty winds reaching 40-50 kmph are also likely over Kolkata and adjoining districts, including Howrah, Hooghly, North and South 24 Parganas, East and West Midnapore, Jhargram, Bankura and Purulia.
The weather office also issued a series of yellow nowcast alerts on Sunday afternoon for parts of Kolkata, Howrah, Hooghly, Bankura, Jhargram, East and West Midnapore, North and South 24 Parganas, Nadia and East Burdwan, warning that light to moderate thunderstorms accompanied by lightning, moderate rain and gusty winds of 30-40 kmph could affect these districts over the next two to three hours.
The most severe rainfall is expected over East Midnapore, West Midnapore and Jhargram, where heavy to very heavy rain (7-20 cm) is likely at isolated places on Sunday. These districts have been placed under an orange alert, while most other districts in South Bengal remain under a yellow watch for thunderstorms, lightning and heavy rain.
The impact of the depression was evident in Sunday’s rainfall figures. Canning in South 24 Parganas recorded the state’s highest rainfall at 37.2 mm, followed by Durgachak in East Midnapore with 34.2 mm, Kalaikunda in West Midnapore with 27.4 mm, and Amfu Kharagpur with 24.6 mm. In North Bengal, Sevoke received 33.2 mm, Lava 31 mm, and Siliguri 28.6 mm during the 24-hour period ending at 8.30 am.
The IMD has forecast that rain will continue across South Bengal through at least July 12, with light to moderate showers likely at many places. Although rainfall intensity is expected to ease gradually after Monday, intermittent thunderstorms and gusty winds are likely to persist across the region.
North Bengal is expected to see increased rainfall from Monday. Heavy rain has been forecast over Darjeeling and Jalpaiguri on July 6, extending to North Dinajpur, South Dinajpur, Alipurduar and Cooch Behar on July 7. Between July 8 and July 9, Jalpaiguri and Alipurduar are likely to receive heavy to very heavy rainfall, while Darjeeling, Kalimpong and Cooch Behar are also expected to receive heavy showers. The IMD has cautioned that the rainfall could trigger landslides in the hilly areas of North Bengal.
