Explain the phenomenon of Western disturbance and discuss its impact on the Indian weather system.

The western disturbance refers to moisture laden, low-pressure disturbances that travel from the Mediterranean Sea region to the Indian subcontinent during winters.

• These disturbances pick up humidity from the Mediterranean sea and travel along with westerlies.
• At times, these low-pressure disturbances may develop into Medicanes (Mediterranean hurricanes).
• They form the primary wind pattern in the Indian subcontinent in winters and have various impacts on its weather system.

Impacts on Indian weather:

• Sudden marked drop in night temperature.
• Winter rainfall in north and north-west India.
• Indicate the inflow of westerlies to the subcontinent.
• May bring a cyclonic storm by Medicanes.
• Helps in growth of winter crops, e.g. wheat, gram, barley.

Western disturbances are an essential feature of the Indian weather system.