Syllabus:

GS 1: Salient features of the World’s Physical Geography.

Context: 

Recently, Delhi and the nearby region experienced heavy rain and strong winds due to a Western Disturbance affecting north and northwest India. 

More on the News

A recent analysis by Climate Trends, a Delhi-based climate research organization, has highlighted the increasing frequency of Western Disturbances in 2025. Their key findings include:

• The increase is directly linked to rising global temperatures.
• Western Disturbances became more frequent from late January 2025 after remaining minimal till that month

The intensified activity has caused:

• Heavy rainfall, flash floods, and landslides in Jammu & Kashmir, Himachal Pradesh, and Uttarakhand during March and April.
• A reduction in prolonged heat waves in the northwestern plains.

What are Western Disturbances 

• Western Disturbances are east-moving rain-bearing wind systems that originate beyond Afghanistan and Iran. 
• They pick up moisture from the Mediterranean Sea, Black Sea, Caspian Sea and the Arabian Sea.

Formation of Western Disturbances:

• Western Disturbances are type of extra-tropical cyclones formed due to the interactions between polar and tropical winds, leading to development of low-pressure areas.
• They are embedded within the subtropical westerly jet stream — a high-altitude, fast-moving air current that flowing from west to east, primarly over the Himalayan and Tibetan highlands.
• These systems are most active during the boreal winter months (December to March) and influence weather in northwestern India, Pakistan, Afghanistan, and Tajikistan.

Impact of Western Disturbances in India

Agricultural Significance:

• These are vital for the growth of rabi crops such as wheat, barley, mustard, and gram, which are sown in winter and harvested in the spring. 
• The winter rainfall they bring is crucial for India's food security, particularly for wheat. 
• They help maintain soil moisture levels, boosting agricultural productivity and overall crop yields. 

Water resources:

• They brings significant snowfall to the Himalayas, vital for glacier health and the perennial flow of rivers like the Indus and Ganges.
• This snowfall contributes to a steady year-round water supply, supporting both agriculture and domestic use. 

Climate Impact: 

• They can cause sharp temperature drops, often leading to cold waves in northern India. 
• These disturbances are associated with cloudy skies, higher night temperatures, and unusual rainfall pattern.

Other Impacts:

• After winter, they can influence the activation of the monsoon in parts of northwest India. 
• While generally beneficial, Western Disturbances can also trigger extreme weather events such as floods, flash floods, landslides, and cold waves. 

Mains Question:

Q. Discuss the phenomenon of Western Disturbances, their impact on India’s weather patterns, and how their frequency and intensity have changed over time due to climate change.