Produced by: Tarun Mishra Designed by: Muskan Arora
New research indicates that winter storms, crucial for providing snow and rainfall to northern India, are arriving later in the year compared to 70 years ago. This delay poses a significant risk of catastrophic flooding and reduces vital water supplies for millions of Indian residents, according to a study published in journal Weather and Climate Dynamics.
Known as western disturbances, these cyclonic storms typically bring heavy snow to the Himalayas from December to March. The melting snowpack in spring supplies irrigation water for crops downstream. However, the study reveals that western disturbances are occurring more frequently during India's summer months.
Over the past seven decades, the frequency of western disturbances has increased by 60% from April to July. This shift results in reduced snowfall and an elevated risk of heavy flooding, particularly during the summer season.
Dr. Kieran Hunt from the University of Reading emphasizes the alarming trend, noting that strong storms are now twice as likely to occur in June compared to 70 years ago. Late storms in summer dump heavy rainfall instead of snow, heightening the risk of deadly flooding events.
Some areas of Kashmir have witnessed no snowfall in December or January, raising concerns for the 750 million people in the Indus and upper Ganges basins who rely on winter snows for water supplies. The loss of winter snow and increased late-season storms exacerbates water scarcity issues.
The research team attributes the seasonal shift to changes in the subtropical jet stream, influenced by the rapid warming of the Tibetan Plateau. This warming creates a larger temperature contrast, fueling more frequent and intense storms.
Global warming weakens the temperature difference between the equator and poles, causing the jet stream to linger at southerly latitudes longer into spring and summer. This allows more storms to strike North India after the winter season.
The combination of delayed winter storms and declining snowfall underscores the urgent need to address the far-reaching impacts of climate change in the region. Without mitigation efforts, India's water problems are expected to worsen as the world continues to warm.