Explained: What are cloudbursts and is their frequency increasing?

Seven people died and more than a dozen were injured and several are still missing in a cloudburst incident in the wee hours of Wednesday in a remote village in Jammu and Kashmirs Kishtwar areaOn Tuesday Himachal Pradeshs Lahaul Spiti district witnessed a similar cloudburst incident followed by flash floods at around 8 pm leaving one dead and several missingThe India Meteorological Department IMD had warned of extremely heavy rainfall in northwest India and the western Himalayan states for Tuesday Monday and Thursday but this forecast did not and cannot predict cloudburst incidentsIt is a very short term and highly localised phenomenon Meteorologists define cloudburst when there is more than 100 mm rainfall in just one hour at a given location There is also a new definition of mini cloudburst which is more than 50 mm rainfall in two consecutive hoursThe new definition distinguishes the cloudbursts associated with high topography eg the Leh event in August 2010 Uttarakhand event in June 2013 and rainfall incidences over the plain region exceeding 100 mm in one hour that can result in urban flooding such as that in Mumbai in July 2005Also read Himachal Pradesh 14 people died due to heavy rains floods in last 24 hoursUnlike cyclones forecasting a cloudburst is very difficult due to the dynamics of the rapidly developing clouds over a very small area the IMD has maintainedAgrees the Head of the Department of Earth Sciences University of Kashmir Shakeel Romshoo In majority of the cases in the Himalayan region cloudbursts happen in small valleysEven with the doppler radar it is difficult to predict as the doppler radars cannot look into those small valleys unlike in plains where it can capture a large area Romshoo saidCloudbursts occur when copious amount of moisture is suddenly lifted vertically upwards resulting in formation of massive cloudsThe sudden updraft is usually due to a localised eddy combined with orographic lifting very common in hilly regions Eddies are swirling motion of fluids that allow intense mixing of dry and moist air Depending on their strength they could form massive tall clouds said associate professor in the Department of Mechanical Engineering amp Adjunct Faculty in IDP Climate Studies IIT Bombay Sridhar BalasubramanianPointing out that the wind patterns are changing due to climate change and the change in wind patterns could in turn impact the dynamics of localised eddies that aid in cloud formation Sridhar said Due to global warming the air temperature is at least one degree higher than normal Warm air can hold more moisture Hence we have more moisture in the air These two phenomena are resulting in increased cloudburst eventsIMDs Pune office maintains data of all weatherrelated incidents across India However there is no separate database dedicated to cloudburst eventsIn view of increasing cloudburst events we now plan to start maintaining such database a meteorologist from Pune saidBut there have been several studies in connection with cloudburstsThe Assessment of Climate Change over India 2020 report released by the Ministry of Earth Sciences last year had documented several instances of cloudburst based on scientific papersIn one such paper studying the distribution of cloudburst and minicloudburst events over the Indian subcontinent during the period 19692015 based on the information from 126 station observations scientists had found that on an average the Indian subcontinent experienced 130 minicloudburst events and one cloudburst event per yearDuring the Indian summermonsoon season there are 23 minicloudburst events witnessed along the Himalayan foothills west coast of India IndoGangetic Plains and Saurashtra and as high as five such events are noticed over central India it stated adding that the onset period of monsoon typically witnesses more intense minicloudbursts average rain intensities by 7 cm per event prominent over the coastal regions of Gujarat and Odisha and the northeastern parts of IndiaRomshoo however disagreed with the claim about increasing frequency of these incidentsCloudbursts have been happening in the Himalayas for ages It generally occurs in some small valleys which in earlier days were not connected So the news come out very late Many a times it would not even be reported What has definitely increased now is the reporting about cloudburst incidents Technological advances such as mobile penetration in remote areas has made it possible to bring these phenomena to the fore Romshoo addedThe Indian subcontinent receives rainfall amounting to more than 6 cm from minicloudburst events during JulyAugust and these events have been observed to be very intense over the eastern part of the IndoGangetic plains during the withdrawal phase of ISMAlthough shortlived cloudburst and minicloudburst occurrences are generally projected to decline in frequency not statistically significant at 5 per cent it is observed that there is a significant increase in these events along the Himalayan foothills 1 per decade and west coast of India 5 per decade while decreasing over northeast India in the recent decades the Assessment of Climate Change over India 2020 report had saidThis story has been sourced from a third party syndicated feed agencies Midday accepts no responsibility or liability for its dependability trustworthiness reliability and data of the text Midday managementmiddaycom reserves the sole right to alter delete or remove without notice the content in its absolute discretion for any reason whatsoever