A thick cover of rain clouds hung over the city on Monday afternoon. The Met office warned of isolated heavy rain in Calcutta and the rest of south Bengal in the next 48 hours. The monsoon current has become strong over Gangetic Bengal following the development of two cyclonic circulations. "One system has developed over Gangetic Bengal and another over Bihar and Uttar Pradesh. Both circulations are sucking in moisture from the Bay of Bengal. We have issued a warning for heavy rain at isolated places during the next two days,' said G.C. Debnath, the director of the weather section of Regional Meteorological Centre, Alipore. The showers, however, are not likely to be as heavy as they were on June 16 and 17. On Monday, the city woke up to an overcast sky and spells of smart showers. As the day wore on, a nagging drizzle settled in. Heavy rain has been predicted at isolated places in north Bengal in the next 48 hours. Picture by Pabitra Das