Under their influence of Western Disturbance Isolated to scattered light rainfall/snowfall activity likely over Western Himalayan Region during 08th-12th February, 2025. The India Meteorological Department forecasted this.

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Western Disturbances

(WD) are low-pressure areas, extratropical storm originating,  embedded in the Westerlies-the planetary winds that blow from west to east between 30 and 60° latitude. The disturbance travels from the “western” to the eastern direction. Disturbance means an area of “disturbed” or reduced air pressure. Equilibrium exists in nature due to which the air in a region tries to normalize its pressure. In the term “extra-tropical storm”, a storm refers to low pressure. “Extra-tropical” means outside the tropics. As the WD originates outside the tropical region, the word “extra-tropical” has been associated with them.

They originate in the Mediterranean region. Travel westward, and enter India loaded with moisture, where the Himalayas obstruct them, causing rain and snow over northern India. The moisture in these storms usually originates over the Mediterranean Sea and Atlantic Ocean. WDs are important to the development of the Rabi crop in the northern subcontinent.  They gradually travel across the middle east from Iran, Afghanistan, and Pakistan to enter the Indian sub-continent. Western Disturbances are low-pressure systems, embedded in western winds (westerlies) that flow from west to east.

 Moreover, Western disturbances, specifically those in winter, bring moderate to heavy rain in low-lying areas and heavy snow to mountainous areas of the Indian Subcontinent. They are the cause of most winter and pre-monsoon season rainfall across northwest India. Precipitation during the winter season is very important in agriculture, particularly for rabi crops.

A Western Disturbance is seen as a cyclonic circulation in middle tropospheric levels over north Iran &
neighbourhood. Ahead of this western disturbance, there is a wind speed divergence in middle tropospheric levels over Northwest India. The Subtropical westerly Jet Stream with core winds of the order upto 135 knots at 12.6 km above mean sea level prevail over Northeast India.