India’s monsoon rainfall, already 7% more than what is normal, has started to withdraw, with the India Meteorological Department (IMD) saying that the system had begun retreating from parts of southwest Rajasthan and Kutch on Tuesday.
The ‘normal’ or average date of withdrawal from southwest Rajasthan was September 17. The withdrawal of the Southwest monsoon was based on meteorological conditions such as anti-cyclonic circulation (dry air that is the opposite of a cyclone), the absence of rainfall in the last five days and water vapour imagery indicating dry weather conditions over the region.
The monsoon withdrawal is a long drawn process and extends into mid-October though the IMD considers September 30 to be the final day of monsoon rain over India. The rain after that is categorised as ‘post monsoon’ rainfall.
