Monsoon: Withdrawal from India starts, says IMD

India Meteorological Department (IMD) on Monday said that Monsoon has started the process of withdrawing from India, that is after a delay of nearly eight days.

"The southwest monsoon has withdrawn from parts of southwest Rajasthan, September 25, 2023, against its normal date of withdrawal from southwest Rajasthan of September 17," it said in a statement.

The weather department had earlier set September 17 as the date of the actual withdrawal.


Withdrawal
The late retreat of the monsoon has been happening for the past 13 years. The monsoon withdrawal of 2022 came a week later than normal, the weather office added.

Withdrawal of the monsoon from northwest India marks the beginning of its retreat from the Indian subcontinent.

Delay in monsoon withdrawal extends the rains which significantly impacts agricultural production, particularly in northwest India where monsoon rainfall plays a crucial role in the Rabi crop production.

Typically, the southwest monsoon makes its onset over Kerala by June 1 and covers the entire country by July 8. It started retreating from northwest India around September 17, withdrawing entirely by October 15.

Weather Conditions

• Anti-cyclonic circulation at 850 hPa level
• No rainfall for the last last 5 days
• Water vapour imagery indicates dry weather conditions over the region

Rainfall in 2023
India has received 780.3 mm of rain during this monsoon season so far, compared to a normal of 832.4 mm.Rainfall between 94 per cent and 106 per cent of the long-period average (LPA) is considered normal.

Normally, the country receives an average of 870 mm of precipitation during the four-month monsoon season (June to September).

In a pre-monsoon briefing, the IMD had predicted a normal monsoon for India, albeit on the lower side of normal. It had, however, cautioned that El Nino -- warming of waters in the Pacific Ocean near South America -- might influence the latter half of the southwest monsoon.

El Nino conditions are associated with weaker monsoon winds and drier conditions in India.

India experienced a rainfall deficit in June but saw excessive precipitation in July due to consecutive western disturbances over northwest India and a favourable phase of the Madden-Julian Oscillation (MJO), known for increasing convection in the Bay of Bengal and the Arabian Sea.

MJO is a large-scale atmospheric disturbance originating in tropical Africa and travelling eastward, typically lasting 30 to 60 days.

August 2023 marked the driest month since 1901 and the hottest ever recorded in India, attributed to the strengthening of El Nino conditions. However, September brought an excess of rain due to multiple low-pressure systems and the positive phase of MJO.

(With agency inputs)