Most parts of India will likely see an extended period of above-normal precipitation during the last two monsoon months of August and September, according to the Busan, South Korea-based APEC Climate Centre. Only exception would be a trend for a likely below-normal rainfall regime along the West Coast, Odisha and Chhattisgarh in August while September is expected to make ample amends, the South Korean agency said.
Good winter monsoon seen
Indications suggest the North-East monsoon may be good for the South Peninsula except occasional blips over extreme South Tamil Nadu and adjoining Kerala. But these could even out into December. The rest of the country may not be as fortunate. This is even as the monsoon is in full flow currently, having reversed the fluctuating fortunes during the first month of June to a comfortable surplus of 14 per cent for the country as a whole as of mid-July, the rainiest of monsoon months.
Weak La Nina may linger
The Australian Bureau of Meteorology has said the the probability for monsoon-friendly La Niña conditions lingering in the Equatorial East Pacific is expected to be above 60 per cent though its intensity is likely to be weak during August 2022 to January 2023. The Indian Ocean Dipole (IOD), its counterpart in the country’s backyard, will likely undergo a flip to a negative phase. Unlike a positive IOD, the negative phase has corelated poorly with the monsoon in the past.
Meanwhile, a low-pressure each on either side of the peninsula – one of them being well-marked – has changed the complexion of the monsoon. The twin engines are powering its most productive phase yet, pouring it down heavily over Gujarat, parts of Central and Peninsular India. The expected movement of the monsoon trough towards the North has not materialised yet since the ‘lows’ have pinned it down to its current axis, which continues to be South of normal.
This is a perfect recipe for active monsoon in the region replete with the presence of a shear zone of turbulence in the higher levels of the atmosphere. The ‘low’ over Odisha (its well-marked cousin is hovering over North-East Arabian Sea and adjoining Saurashtra and Kutch) will drop anchor over east India for a few days before guiding itself and the monsoon trough towards north-west India, dragging the belt of heavy rain along. Arrival of a western disturbance opens up the prospect of interaction with the monsoon current resulting in damaging rain, floods, and landslides along the hills.