North India is undergoing a significant meteorological shift as the southwest monsoon enters its final phase of withdrawal. This seasonal transition is being marked by the influence of a Western Disturbance, bringing unexpected rainfall to several regions.
Monsoon Retreat and Western Disturbance Interaction
Satellite imagery from India’s INSAT-3DS satellite vividly illustrates the changing weather patterns. Images from September 23 showed extensive cloud cover across northern and northeastern India, while by September 27, much of the northwestern and central parts of the country appeared considerably clearer, indicating the monsoon's receding influence.
The southwest monsoon's withdrawal began in parts of northwest India and is progressively moving towards central and eastern regions. Concurrently, a Western Disturbance swept across northern India on Friday and Saturday, altering cloud distribution. These eastward-moving weather systems originate in the Mediterranean and are known to cause cloudiness, rain, and thunderstorms in northern India, especially when interacting with existing moisture.
This particular Western Disturbance, interacting with a depression over central India, has triggered rainfall across parts of Uttar Pradesh, Uttarakhand, and the Delhi-National Capital Region, even as the broader monsoon withdrawal continues its course.
Outlook for Monsoon Withdrawal
Rainfall activity across many parts of the country is anticipated to diminish towards the end of September, with September 29 highlighted as a potential turning point for drier conditions to prevail. However, the complete withdrawal of the southwest monsoon from India is not tied to a single, fixed date.
The India Meteorological Department (IMD) evaluates several factors before officially declaring further monsoon withdrawal, including:
- Cessation of rainfall
- Declining atmospheric moisture levels
- Changes in wind circulation patterns
Even after the official monsoon retreat, localized weather systems can still generate rainfall, particularly in southern and eastern India. This period marks India's transition from the four-month southwest monsoon season towards the cooler months ahead.