Kolkata, 05 June (H.S.):

Despite intense thunderstorms and heavy rains across South Bengal on Tuesday night and Wednesday evening, the official onset of the southwest monsoon remains pending, according to weather experts. Meteorological conditions necessary to declare the monsoon have not yet been met in the region.

Kolkata and surrounding areas witnessed sudden and intense downpours on Wednesday evening, accompanied by loud thunder and dramatic lightning displays. Kolkata recorded 38 mm of rainfall in just three hours, while Salt Lake received 81 mm and Dum Dum logged 57 mm. The towering clouds, reaching up to 8 km in height, and continuous thunder created panic in several neighborhoods.

However, the India Meteorological Department (IMD) clarified that these rain events, though significant, do not meet the required criteria for monsoon declaration. For the official onset of the southwest monsoon, at least 70 percent of the region’s weather stations must record 2.5 mm or more rainfall over two consecutive days in June. In addition, specific atmospheric parameters like wind patterns, surface pressure, and radiation balance must align appropriately.

Dr. Ravindra Goenka, a leading meteorologist, explained that the recent rain spells were due to strong local atmospheric developments rather than a monsoon system. “These pre-monsoon storms occur when thick, tall clouds and suspended dust particles interact, creating ideal conditions for intense lightning and heavy showers over short durations,” he noted.

It is worth mentioning that the southwest monsoon arrived in Kerala earlier than usual this year, on May 24 instead of the normal June 1. It also advanced into North Bengal on May 29, nearly a week ahead of schedule. This had raised hopes for an early arrival in South Bengal as well.

However, meteorologists believe that a recently formed low-pressure area in the Bay of Bengal diverted moisture towards the northeastern states, slowing down monsoon progress in South Bengal.

Scattered Rain and Humidity to Continue

While the official monsoon declaration is still awaited, South Bengal is likely to experience scattered light to moderate rainfall and high humidity levels over the coming days. Full-fledged monsoon conditions are expected only after the required meteorological benchmarks are fulfilled.

Hindusthan Samachar / Satya Prakash Singh