More flash floods, landslides? IMD warns India set for wetter September; what’s causing record rainfall

NEW DELHI: India is likely to get more than normal rainfall in September, adding to a monsoon season already marked by extreme weather and heavy damage from rains.The India Meteorological Department (IMD) on Sunday said that rainfall in September is expected to be more than 109% of the long-period average of 167.9 mm. The forecast indicates that most parts of the country will receive normal to above-normal rainfall, although the northeast, east, several areas in the extreme south peninsula and pockets of northwest India could record below-normal rain.IMD director general Mrutyunjay Mohapatra cautioned that intense rainfall could lead to fresh disruptions. He said Uttarakhand may face landslides and flash floods, while south Haryana, Delhi and north Rajasthan could also see major impacts.”Many rivers originate in Uttarakhand. So, heavy rainfall means many rivers will be flooded and it will impact cities and towns downstream. So, we should keep this in mind,” he said.He further warned that heavy showers are also likely in the upper catchment areas of the Mahanadi River in Chhattisgarh.Mohapatra noted that September rainfall has shown a slight rising trend since 1980, except for lean years such as 1986, 1991, 2001, 2004, 2010, 2015 and 2019. Alongside the rain forecast, the IMD said September temperatures will vary across regions. Maximum temperatures are expected to stay normal to below normal in many parts of west-central, northwest and south India, while they could be above normal in east-central, east, northeast India, parts of northwest India and the western coast.Between June 1 and August 31, India received 743.1 mm of rainfall, around 6% higher than the long-period average of 700.7 mm. June saw 180 mm of rain, nearly 9% above normal, followed by July with 294.1 mm, 5% above average. August recorded 268.1 mm, about 5.2% above normal.Northwest India had an unusually wet August, with 265 mm of rainfall, the highest for the month since 2001 and the 13th highest since 1901. Cumulatively, the region logged 614.2 mm of rain from June to August, 27% higher than the normal 484.9 mm.South Peninsular India also saw heavy rainfall in August, receiving 250.6 mm, 31% above normal, making it the third highest August total since 2001 and the eighth highest since 1901. Overall, the region registered 607.7 mm between June and August, a surplus of 9.3%.The unusually heavy rains have fuelled extreme weather events across several states. Punjab saw its worst floods in decades, with overflowing rivers and breached canals inundating vast stretches of farmland and displacing lakhs of people. In Himachal Pradesh, Uttarakhand and Jammu and Kashmir, cloudbursts and flash floods triggered landslides and caused extensive loss of life and property.The IMD said the surplus rainfall was the result of active monsoon conditions, boosted by frequent western disturbances. Mohapatra explained that disturbances between July 28 and August 14 brought heavy to very heavy rainfall to the western Himalayas and nearby plains, including a flash flood and landslide in Uttarkashi on August 5 and riverine floods in Uttar Pradesh and Bihar.He added that a rapid revival of the monsoon after August 14, sustained by four low-pressure systems over 15 days, prolonged active rainfall across large areas.According to Mohapatra, northwest India and adjoining Himalayan states faced “extremely and exceptionally heavy rainfall events” between August 21 and 27. He said this included very heavy rain over east Rajasthan from August 22 to 24, over Punjab and Haryana between August 23 and 26, and severe flooding and landslides in Jammu and Kashmir from August 23 to 27.Other intense spells were recorded in Konkan and the ghats of Madhya Maharashtra on August 20, east Rajasthan on August 23, Jammu on August 27 and Telangana on August 28.Mohapatra said these events were driven by “the slow movement of two successive very active western disturbances, interaction with remnants of monsoonal low-pressure systems, strong southerly winds with moisture incursion from the Bay of Bengal and Arabian Sea and formation of two low-pressure systems over north Bay of Bengal and their movement across central India”. Go to Source