The slow progress may lead to water scarcity, food insecurity and humid heat, especially for north-west India
India may be staring at a delayed and dry southwestern monsoon in the first two months, with late onset, intermittent rains and dry spells in many regions.
For Delhi and adjoining regions of north-west India, the dry spell may last through August 14. This could affect the availability of water for sowing of kharif crops in the region and farmers may chose to sow later than usual.
Thus the farming season may again be pushed back, as it was in 2021.
It may also mean a return of heat. Combined with higher humidity, that can make for a couple of hot, sticky months.
The much-awaited monsoon winds reached Kerala May 29, according to the India Meteorological Department (IMD) — two days later than earlier predicted but three days ahead of its normal schedule.
The weather agency further predicted May 30 that monsoon would advance over some parts of Tamil Nadu, Karnataka and the north-eastern states in three-four days. There will be a brief dry spell over Kerala between June 3 and June 9 with 45 per cent less rain than normal.
The monsoon onset has been tricky this year. It set over Bay of Bengal May 16 — six days earlier than normal. This was due to the formation, progress and dissipation of twin cyclones Asani and Karim in north and Indian Ocean respectively.
For the past two years multiple cyclones later into May and even in early June helped pull the monsoon winds over the Indian sub continent causing early onset, even floods, in many parts of the country.
Cyclone Asani dissipated in the second week of May and helped the monsoon move into the Andaman Sea but did not pull it further.
Around May 20 the winds, after three days of good progress, stalled over the Bay of Bengal and have barely moved since then. There is a misbalance between the Arabian Sea and Bay of Bengal branches of the monsoon trough. The Arabian Sea branch has moved ahead causing the onset over Kerala May 29 and over some parts of Tamil Nadu May 30 but the Bay of Bengal branch remains stalled.
Raj Bhagat, a private weather expert, even contested the declaration of monsoon onset.
Rather than using fixed thresholds for declaring #monsoon onsets, we should start using (and developing) Monsoon #indices that talk about strength and phase which help us understand the patterns better. pic.twitter.com/ZzrOlmcVKJ— Raj Bhagat P #Mapper4Life (@rajbhagatt) May 30, 2022
Bhagat, who works for the World Resources Institute in Bengaluru, claimed views expressed on the microblogging site Twitter were personal.
The monsoon trough’s further progress over India may also remain slow with only intermittent rains in the beginning and dry spells. The onset over central India could be around June 14-19, forecast climate scientist Elena Surovyatkina. The normal monsoon onset date for central India is during June 10-15.
Surovyatkina, from the Potsdam Institute of Climate Impact Research, Germany, generates a monsoon onset forecast 40 days in advance for central India, Telangana and Delhi every year. She also generates a monsoon withdrawal forecast 70 days in advance for the same regions.
The monsoonexpert uses a unique systems perspective to declare the onset and withdrawal of monsoon over the Indian sub continent. Within this she observes the transition of the monsoon season based on temperatures recorded in the northern Pakistan region and a particular region in central India. When these temperatures cross certain thresholds she declares the onset of the monsoon or withdrawal of rains.
This year Surovyatkina has also included a forecast of intermittent rains and dry spells. For central India which comprises of south eastern part of Maharashtra, western Chattisgarh and northern Telangana she predicted a dry spell between June 19 and June 26 and continuous rainfall after that.
The rains may be further delayed in north-western India, which may bring back heat waves as Down To Earth wrote earlier. The onset of monsoon over Delhi may happen around July 10 with intermittent rains and short dry spells continuing till July 29. There may not be much respite even after that as Surovyatkina forecast a longer dry spell from July 29 to August 14, after which there may be more continuous rainfall.
This would mean a delay in the arrival of the monsoon season by 10-15 days, as the normal monsoon onset date for Delhi is between June 25 and June 30 and a wait of another month for more continuous rainfall. The rains for north west India had been delayed by almost three weeks in 2021 as well when the monsoon winds had stalled after a good initial progress due to many global climatic factors.
“A slow progress might aggravate the water and food security of those regions in the north/northwest India that have been already hit by a rain deficit and heatwaves during March-May”, Roxy Mathew Koll, a climate scientist at the Indian Institute of Tropical Meteorology, Pune, told DTE.
The latter phase of the monsoon may be better owing to the persistent La Nina phenomenon in the equatorial Pacific Ocean, which is in its third year in 2022. The La Nina is the cooler than normal phase of the El Nino Southern Oscillation phenomenon and generally supports good rainfall over India.
“However, there is no clear relationship established between onset or the initial phase of monsoon and the latter phase of the monsoon. If ocean-atmospheric conditions are favourable, monsoon can pick up at a later time and makeup for the aggregate seasonal rainfall,” Koll said.
“At the same time, we need to be aware that a slow onset could have already hit the agriculture badly, and receiving the pending rains in a short time need not necessarily help it,” he added.
However Raghu Murtugudde, a climate scientist at the University of Maryland, explained that “the warm temperatures and the dust storm over the Middle East should favour the monsoon”.
He further highlighted that June rains comprise only 20 per cent of the monsoon season and the peak monsoon rainfall occurs in July and August which could be normal because of the ongoing La Niña. Even then he cautions that the “weaker monsoon circulation may dominate but La Niña should help”.
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