The extreme south-eastern coast of Tamil Nadu, Sri Lanka and most of Maldives are likely to see below normal rainfall during the October-December period, according to a consensus outlook by the 17th session of the South Asian Climate Outlook Forum (SASCOF-17) held online on September 23 and 24.

The Ramanathapuram, Thoothukudi, Tirunelveli and Kanniyakumari districts in Tamil Nadu and the adjoining Thiruvananthapuram district in Kerala may be affected as per this outlook. Fortunately, all these districts have received normal-to-above normal rain during the South-West monsoon.

The worrying part of the outlook is an extended deficit rain situation for the hills of North-West India (Jammu & Kashmir, Himachal Pradesh, Ladakh and Uttarakhand) and parts of the adjoining plains of Punjab, Rajasthan, Haryana, Chandigarh, Delhi and West Uttar Pradesh.

However, the below normal rainfall over the north-western and northern parts of South Asia, including some areas along the foot hills of the Himalayas is not too surprising. SASCOF-17 reiterated that these areas climatologically receive very low rainfall during this season.

Earlier this month, the Busan, South Korea-based APEC Climate Centre, too, had said that most areas of the country, except parts of Jammu & Kashmir, Himachal Pradesh and Punjab, may see normal-to-above normal rain during October-December.

Timely rains for Australia

The proximate reason for the below-normal rainfall in the South could be the building negative Indian Ocean Dipole (IOD) marked by the abnormal warming of the eastern basin, which could help Australia farther to the South-East with a timely (if not early) monsoon and above-normal rainfall this year.

This is the exact reverse of the last year, when an unprecedented strong positive IOD delayed the exit of the monsoon from India (October 9, most delayed on record) that extended into the Australian season, delayed the monsoon resulting in creating drought and record wildfires.

Above-normal rain is indicated for Odisha, Andhra Pradesh, Telangana, North Interior Karnataka, Goa, Konkan, and Mumbai during October-December. A similar outlook is valid also for southern parts of Myanmar, the SASCOF-17 outlook said.