New Delhi, Oct 15 : Six weeks after catastrophic flooding swept through Nepal on August 26, fresh flash floods have wreaked havoc again, this time in the Himalayan nation’s Gorkha district, leaving five people missing and prompting scientists to point to the changing dynamics of Western Disturbances and the accelerating impact of climate change.
According to Nepal’s National Disaster Risk Reduction and Management Authority (NDRRMA), a major landslide occurred between Lokpa and Chumling in Chum Nubri Rural on October 11, 2026, blocking the Budhigandaki River. The blockade triggered a large flash flood carrying debris downstream, causing widespread physical damage. So far, 95 people have been rescued, including nine foreigners, while five remain missing.
Preliminary assessments by the NDRRMA paint a picture of significant destruction. Two concrete bridges, two suspension bridges, and one Bailey bridge have been destroyed. Three hydropower projects, four Havan kundas, four sheep sheds, and five vehicles have also been damaged.
In terms of residential damage, 43 houses were destroyed in Chum Nubri RM Ward 3, 39 in Dharche RM Wards 1, 3, and 5, 64 in Arughat RM Ward 5, and 58 in Tripurasundari RM Ward 2. A school, 12 pigsties, and storehouses have also been damaged, according to official data.
The disaster has once again spotlighted the increasing vulnerability of the Himalayan region to extreme weather events, with meteorologists and climate scientists drawing a direct link between global warming and the intensification of these disasters.
Mahesh Palawat, VP-Meteorology and Climate Change at Skymet Weather, explained the immediate meteorological trigger. “An active Western Disturbance was passing through the Himalayas, which has given widespread rainfall across the Himalayas. There is no doubt that there has been a rise in temperatures as well as the moisture content. Every degree rise in the atmospheric temperature increases the capacity of clouds to hold water vapour by seven percent, making rains torrential, especially in the Himalayas. The number of heavy rain days has increased. Similar conditions persisted over Nepal, which could have resulted in a rise in the water levels of the river,” he said.
Dr K J Ramesh, Former Director General of the India Meteorological Department, pointed to a deeper, structural shift in weather patterns driven by Arctic warming. “We cannot read the weather without accounting for the impact of global warming. Arrival of an active western disturbance is a common phenomenon during this time of the year. After the withdrawal of the monsoon, the subtropical western jet moves south of the Northern Hemisphere, which then pushes the western disturbance towards the south of the Himalayas. However, with the steady acceleration of Arctic melting due to climate change, these subtropical western jets are travelling much further south than their normal position,” he said.
“When these weather systems are pushed deep, they attract and interact with moisture from the Arabian Sea, which is already emitting water vapour in abundance due to record warming. It is now established that western disturbances will be stronger during the post-Monsoon and winter season,” Ramesh added.
The long-term prognosis is equally concerning. According to a report by the International Centre for Integrated Mountain Development (ICIMOD), limiting warming to 1.5 degrees will result in a 2-degree increase in the mountains. If current emission trends persist, temperatures could rise by more than 5 degrees in the Hindu Kush Himalaya. This is due to “elevation-dependent warming,” a phenomenon where warming is amplified with elevation, meaning temperatures in high-mountain areas increase at a faster rate than environments at lower altitudes.
Professor A P Dimri, Director of the Indian Institute of Geomagnetism, raised concerns about the cumulative nature of these disasters along the southern rim of the Western and Eastern Himalayas. He noted that the subtropical westerly jet (SWJ) has reported meridional expansion, giving Western Disturbances more space to oscillate and propagate.
“In the present changing scenario, western disturbances, which are travelling along the southernmost limit of SWJ — which in earlier decades remained northward during summertime — are adding the vagaries together, pulling the monsoon trough northward and providing a higher amount of precipitation. These disturbances are now travelling south of their normal position, giving torrential rains over the region. Nepal witnessed similar conditions two days ago, when the western disturbance interacted with the moisture from the Arabian Sea,” Dimri said.
The interaction of Western Disturbances with the Himalayas plays a crucial role in orographic control — the precipitation mechanism formed when moist air is lifted as it flows above a mountain range. However, increases in global mean temperature have changed the dynamics of these disturbances, making it critical to understand the role of climate change in shaping future weather events in the region.
As per the latest assessments, Nepal’s disaster authority has reported damage to 204 houses across four local areas, though the extent of damage varies and these should not all be counted as destroyed. Authorities have sent around 200,000 emergency alerts and are investigating the flood’s cause and response timeline.
(With inputs from Kartiki Negi)
