Kolkata received widespread rain on Thursday afternoon and evening, ending a hot and humid spell and bringing the temperature down by around eight degrees within a few hours. The Met office recorded about 12mm of rain till 5.30pm, while the city is likely to see cloudy skies and more rain over the next few days.
The maximum temperature had touched around 35°C on Wednesday and stood at just over 34°C on Thursday. The minimum relative humidity was 60%, creating sweaty conditions and an atmosphere conducive to thunderstorms, according to the report from the Met office.
The sky became increasingly cloudy during the day. At around 3pm, the Met office issued a warning of moderate thunderstorms and intense rain. The rain that followed was widespread but not intense, and was accompanied by lightning and thunder. By 6.30pm, the temperature had fallen to around 26°C.
A Met official attributed the change to the revival of monsoon conditions over south Bengal. “The monsoon currents over south Bengal had been weak for the past couple of days. They have now turned active. A trough from Sikkim to Odisha, the position of the monsoon trough and pent-up surface heat combined to bring rain,” the official said.
The monsoon trough passed through Digha on Thursday. The current forecast indicates that Kolkata may continue to experience cloudy skies and rain over the coming days, although the report does not provide a specific rainfall total for the city beyond Thursday’s recorded figure.
The Met office is also tracking another weather system developing near India’s southernmost tip. A Thursday Met report said an upper-air cyclonic circulation over north Thailand could lead to the formation of a low-pressure area over the north Andaman Sea around Saturday evening. The system is expected to intensify as it moves towards India’s east coast and then travel west-northwestwards towards the south Odisha-north Andhra Pradesh coasts over the following three to four days.
The development has prompted social-media posts warning of an “impending cyclone”. The Met office, however, has dismissed those alerts as premature. H.R. Biswas, head of the Regional Meteorological Centre in Alipore, said there was no further prediction that could be made at present and that a more detailed forecast might be possible after September 19.
The report also noted that while monsoon currents were becoming active over Bengal, they were weakening in the westernmost parts of India. A Met report said conditions were becoming favourable for the southwest monsoon to begin withdrawing from parts of West Rajasthan around September 19. October to December is one of the two recognised cyclone seasons in the north Indian Ocean, covering the Bay of Bengal and the Arabian Sea.
