Kolkata: This year, Kolkata has received 362 mm of rain in July so far, recording 49% higher than the normal count. Gangetic Bengal has clocked a surplus of 30% between July 1 and July 20. The city and south Bengal could end the month with excess rain since another wet spell is expected from Thursday. The normal rain count for Kolkata in July is 396 mm. The Met office says this could be the wettest July in several years. Twin impact of both local troughs and low-pressure systems over the Bay of Bengal led to consistent heavy rain this month, said weathermen.The city has received 141 mm of rain in the last week. With 84.1 mm rain, Saturday was the second wettest day of the season. In four years, July 8 turned out to be the wettest July day with the rain count being 87 mm. “While Saturday’s rain was triggered by a local trough and an active monsoon trough, we had a heavier downpour triggered by a low-pressure system and a cyclonic circulation, apart from an active monsoon trough, on July 8. Since the monsoon trough has been hovering close to south Bengal for quite some time now, rain has been frequent with intermittent heavy spells. Also, we have had local troughs more frequently this month,” said Regional Meteorological Centre (RMC) weather scientist, Sourish Bandopadhyay.A low-pressure area is likely to form over the North Bay of Bengal on July 24. It is set to trigger heavy rain in coastal Bengal on July 23 and 24, said the RMC. “The rain could get very heavy in the coastal areas on July 24, while Kolkata and the rest of south Bengal may receive heavy rain,” it predicted. A bulletin issued by the RMC on Sunday read: “In the presence of monsoon flow and strong moisture incursion, light to moderate rainfall at most places with isolated heavy-to-very-heavy rainfall is very likely over districts of north Bengal during July 20-22. Due to the anticipated low-pressure area over the north Bay of Bengal, rainfall activity is likely to increase with isolated heavy-to-very-heavy rainfall very likely over districts of south Bengal from July 23.”In 2024, Kolkata had a rain deficit of 10% till July 22. “It was still normal since a surplus or deficit of up to 19% is taken to be usual. But this year, July has been exceptionally rainy,” said Bandopadhyay. Kolkata recorded deficit rain during July in 2011, 2012, 2016, and 2018. In 2015, Kolkata had an 84% surplus in July.
