La Nina phenomenon likely to delay monsoon withdrawal

New Delhi: The developing La Nina phenomenon and local weather systems will strengthen rainfall and delay the withdrawal of the monsoon, meteorologists said.

Although total rain since the season started on June 1 has been 7% above normal, the monsoon has been uneven, as it was deficient in July, very strong in August and 25% below average so far this month.

Rain clouds are expected to strengthen over the next two weeks as low-pressure areas develop in the Arabian Sea and Bay of Bengal. This will in turn delay the withdrawal of the vital weather system, the India Meteorological Department (IMD) said.


"At least for the next 15 days, we do not see the monsoon withdrawal beginning due to the formation of the low-pressure areas," M Mohapatra, DG of IMD, told ET.

Mohapatra said weak La Nina conditions have also helped delay the withdrawal. La Nina is a weather phenomenon caused due to cooler-than-normal Indian Ocean waters, and usually gives a boost to the Indian monsoon, causing above-normal rainfall.

The monsoon starts withdrawing first from Rajasthan. It normally starts withdrawing on September 17 in Pokharan, and September 19 onwards in Jodhpur.

Southern Indian states are likely to see excessive rainfall over the next two weeks, while the northeast will continue seeing torrential downpour over the same period. Coastal and interior Maharashtra, along with Madhya Pradesh might see heavy rainfall next week.

North India will continue to see little or no rain. The subdivision, which comprises of important agricultural states such as Punjab, Haryana, Uttar Pradesh, and Rajasthan, has seen deficient rainfall for most of the monsoon season. Till Friday, the shortfall stood at 12% for the region.