Poor monsoon due to El Nino winds from Pacific

When the World Metereological Organisation (WTO) warned our weather experts in June that a poor monsoon was coming , and also told them why, the latter wouldn’t agree. Now they do.

In June, WMO had predicted the Indian monsoon would be affected due to a probable development of warm El Nino-type winds in the Pacific Ocean region.

After the poor monsoon performance in July and this month, experts here at the India Meteorological Department (IMD) and the Indian Institute of Tropical Meteorology (IITM) are saying the same thing.
 

THE DRY SPELL The most rain-deficient regions in India till August 12
Region	Normal rainfall (mm)	Actual rainfall (mm) /	Shortfall (%)	Remark
Western UP	456.8	147.6	68	Scanty
Haryana	286.1	98.4	66	Scanty
Telangana (AP)	464.4	188.2	59	Deficient
Eastern UP	539.5	251.3	53	Deficient
Rayalseema (AP)	187.2	91.5	51	Deficient
Himachal Pradesh	497.5	245.4	51	Deficient
Jharkhand	667.3	339.5	49	Deficient
Marathwada (Mah)	407.3	214 .0	47	Deficient
Source: IMD, Pune

However, they also believe the same development would benefit the progress of the north-east monsoon, also known as the 'reverse monsoon'.

El Nino is a weather anomaly responsible for deficient rainfall and drought situations globally. IMD now believes the El Nino impact might bring the weakest rains in India since 2002-03.

"The dry spells and poor performance of the monsoon from the fourth week of July and onwards is definitely due to the El Nino situation that has developed over the central parts of Pacific ocean. The situation is expected to continue till the end of October," S Pai, director, National Climate Centre, IMD, told Business Standard.

The developments raise concern for Bihar, Uttar Pradesh, Haryana and Rajasthan. These regions have been the worst hit and do not benefit from the reverse monsoon or the north-east monsoon. "We are still not able to identify the reasons for the deficient rains in the month of June. But the weak monsoon in July and August is surely due to the development of a mild El Nino," said Krishna Kumar, a researcher at the IITM.

While the south-west monsoon has seen the adverse impact of El Nino, the north-east monsoon might see a positive impact of this weather condition. This development is significant for states like Andhra Pradesh, Chhattisgarh, Tamil Nadu, Karnataka, Kerala and certain parts of Maharashtra and Madhya Pradesh. "El Nino helps the progress of the reverse monsoon. Especially, the southern states in India receive heavy rains due to the reverse monsoon. The reverse monsoon begins from October onwards and this impact would definitely be observed," Pai stated.

Krishna Kumar agreed. "El Nino has already done severe damage to this year's annual rainfall. And there are hardly any chances of damage recovery over the remaining season. However, we believe, the El Nino effect should help the north-east monsoon produce better results," he said.

Marathwada in Maharashtra, east Madhya Pardesh, Telangana and Rayalaseema in Andhra, and states in the north-east region might get good rain from the north-east monsoon, Kumar added.