Kolkata: Another thunderstorm lashed Kolkata on Monday afternoon, leaving several pockets in the southern part of the city under water. This was the fifth significant thunderstorm to strike the city in the past 11 days.
The Met office has not ruled out similar thundershowers in Kolkata and the rest of south Bengal till the monsoon current gets reactivated.
The IMD is keeping track of weather developments over the Bay of Bengal that could bring an end to the sluggish monsoon flow the city and the southern part of Bengal are facing. The Met officials indicated the possibility of the monsoon current gaining strength in about a week.
The short and sharp thundershower spell, though less in intensity than the one that hit Kolkata on June 25, left parts of Jodhpur Park, Jadavpur, Gariahat, Patuli, Garia and Behala inundated. Even as Alipore recorded only about 27 mm of rain, KMC's drainage pumping stations in several areas recorded much higher rain amounts. Adding to the water woes was the high tide, due to which lock gates were closed from 11.30 am to 3 pm.
Jodhpur Park locality recorded the highest rain amount of 91mm, followed by Kamdahari (Garia) of 80 mm and Kalighat 54.4 mm, most of it within half an hour between 3 pm and 3.30 pm. The central and north Kolkata localities, however, recorded lighter rain ranging between 20 and 25 mm. Met officials said such a vast difference in rainfall occurs when the showers are caused by local thundercloud development, while the rain pattern caused by systems like low pressure or cyclonic circulation is more uniform.
"The rain spell was very sharp in some areas. Till the monsoon current gets activated, we can expect such thundershower activities in gaps of one or two days," said Regional Meteorological Centre Kolkata head HR Biswas.
Even as the monsoon flow has been active in north Bengal in the past few days, its weak flow in south Bengal has triggered frequent thunderstorms in districts including Kolkata.
"Our extended forecast indicates the possibility of a bigger system like a low pressure area or a cyclonic circulation around Friday. If that happens, the monsoon current will get activated in southern parts of Bengal and bring more uniform and widespread rain. We are closely monitoring the weather development, and we can be more certain about it in another two days," added Biswas.
The Met officials indicated that in case a low pressure area develops, Kolkata, along with some parts of south Bengal, could be lashed by heavy monsoon rain minus the thunder and lightning strikes around the weekend.
"In view of favourable wind pattern and strong moisture incursion from the Bay of Bengal, thunderstorm and associated activities are very likely to continue over some districts of West Bengal along with heavy to very heavy rainfall (7-20 cm) accompanied by extremely heavy rain in some parts of north Bengal," said a special IMD bulletin.
Despite the weak monsoon flow, the frequent thunderstorms have given the city a rain surplus of around 25%, with a monthly cumulative of 336.7 mm this June.