A violent rush of water and sludge that swept through the village of Dharali in India’s Uttarakhand state has left at least four people dead and more than 100 missing, with officials pointing to a rare but increasingly common weather phenomenon known as a cloudburst as the likely trigger.
The Indian Meteorological Department reported extreme rainfall levels of over 210mm within 24 hours across northwest India, including in Uttarakhand where the disaster unfolded.
State chief minister Pushkar Singh Dhami said the village had been struck by a cloudburst shortly before the devastating surge engulfed homes and cut off entire communities.
A cloudburst refers to an intense downpour over a small area — typically no more than 30 square kilometres — at rates exceeding 100mm per hour. These events are especially common in mountainous regions during the monsoon season.
In the Himalayas, moisture-laden air, often originating from the Arabian Sea, is pushed upwards by the steep slopes in a process called orographic lift. The result is towering cumulonimbus clouds that eventually collapse under their own weight, releasing sudden and massive amounts of rain.
Ruchit Kulkarni, a meteorologist at the University of Melbourne, said such cloudbursts often leave little time to respond.
“The clouds keep building with no chance for rain to fall gradually. Eventually, the system dumps everything at once,” he explained.
While cloudbursts can occur naturally, scientists warn that the intensity and frequency of extreme weather events in India have increased with rising global temperatures. A similar event in 2013 at Kedarnath, also in Uttarakhand, killed more than 6,000 people. Research later found that more than half of the rainfall during that catastrophe was likely linked to climate change.
Investigations are ongoing to determine whether other factors, such as a glacier or glacial lake burst, contributed to the latest tragedy.
