Uttarakhand to Himachal to J&K, why this winter feels snowless (Dry winter for country but northwest region particularly hit, receiving just 8 per cent of rain expected), Pg3

Key Highlights:

• Northwest India experienced a significantly dry winter, receiving only 8% of expected rainfall.
• Uttarakhand recorded no rainfall in December and January, while Himachal Pradesh had its sixth-lowest rainfall in December since 1901.
• Weak Western Disturbances with low moisture content are the primary cause of reduced precipitation.
• Lack of snow increases the risk of forest fires, with over 1,600 fire alerts in Uttarakhand since November 1.

Detailed Insights:

• The dry winter is attributed to weak Western Disturbances failing to trigger adequate rainfall due to low moisture and shallow pressure troughs.
• Reduced snow persistence, caused by high diurnal temperature variation, exacerbates the impact of delayed precipitation.
• Decreased snowfall and early melting of glaciers can lead to the formation of proglacial and supraglacial lakes, increasing the risk of glacial lake outburst floods.
• The lack of winter precipitation is detrimental to rabi crops that rely on irrigation supported by snow and rainfall for groundwater recharge.
• Forest fires are increasing in the Himalayas due to the lack of moisture in the forest floor, posing a threat to biodiversity and ecosystems.
• The Equilibrium Line Altitude on glaciers may shift upwards, reducing the volume of water discharge to rivers.
• The India Meteorological Department (IMD) forecasts light to moderate rainfall in northwest India between January 18-20 due to an approaching Western Disturbance.

Key Concepts Involved:

• Western Disturbance: An extratropical cyclone originating in the Mediterranean region, bringing winter rainfall to northern India.
• Rabi Crops: Crops sown in winter and harvested in spring, including wheat, barley, and mustard.
• Glacial Lake Outburst Flood (GLOF): A sudden release of water from a glacial lake, often caused by the failure of a natural dam.