Biparjoy's remnant may help advance monsoon over east India: Meteorologists

The remnant of cyclone Biparjoy is expected to bring rain over parts of Uttar Pradesh and Madhya Pradesh starting Sunday, and help the monsoon advance over east India currently in the grip of a severe heat wave, meteorologists said on Friday.

The monsoon's progress has remained sluggish since May 11 in the absence of any weather system over the Bay of Bengal. Cyclone Biparjoy also impacted the southwest monsoon current, they said.

Biparjoy's remnant is likely to move north-eastwards and give rainfall in central and east Uttar Pradesh and Madhya Pradesh, they said. 

"It may happen... we are monitoring the situation. There could be some other parameters too, such as an increase in cross-equatorial flow over the Arabian Sea and the Bay of Bengal. That can also help advance the monsoon in addition to this (remnant of the cyclone)," IMD Director General Mrutyunjay Mohapatara said when asked if the system can help the monsoon advance over east India.

He chief said conditions will be favourable for the advance of the monsoon over east India and some more parts of south India from June 18 to June 21.

"After giving heavy rainfall in Rajasthan, the system will lead to rain in central and east UP and Madhya Pradesh June 20 onwards. It will pull the monsoonal winds and help the monsoon advance over east India," said Mahesh Palawat, vice president (meteorology and climate change) at private forecasting agency Skymet Weather.

The monsoon hit India on June 8 with its onset over Kerala, a week later than normal.

Some meteorologists attribute the "delayed" and "mild" monsoon onset over Kerala to the cyclone. However, the IMD thinks otherwise. .

The monsoon has so far covered the entire northeast, Tamil Nadu, Kerala, parts of Andhra Pradesh, Karnataka and a few parts Bihar and West Bengal.

The annual rain-bearing system covers Goa and southern most parts of Maharashtra, most parts of Karnataka, remaining areas of Tamil Nadu, some parts of Telangana, south coastal Andhra Pradesh and northeast India by June 10.

It covers more parts of Maharashtra, most areas of Telangana, south Chhattisgarh, remaining areas of coastal Andhra Pradesh, some southern and eastern areas of Odisha, most parts of West Bengal, Sikkim and some eastern areas of Bihar and Jharkhand by June 15.

Research shows a delay in the monsoon onset over Kerala (MOK) does not necessarily mean a delay in the monsoon onset over northwest India.

However, a delay in the MOK is generally associated with a delay in onset at least over the southern states and Mumbai.

Scientists say a delayed MOK also does not impact the total rainfall over the country during the season.

India is expected to get normal rainfall during the southwest monsoon season despite the evolving El Nino conditions, the IMD had earlier said.

El Nino, which is the warming of the waters in the Pacific Ocean near South America, is generally associated with the weakening of monsoon winds and dry weather in India.

The IMD, however, has emphasised that not all El Nino years are bad monsoon years.

Northwest India is expected to see normal to below-normal rainfall. East and northeast, central, and south peninsula are expected to receive normal rainfall at 94-106 per cent of the long-period average.

Rainfall less than 90 per cent of the long-period average is considered 'deficient', between 90 per cent and 95 per cent is 'below normal', between 105 per cent and 110 per cent is 'above normal' and more than 100 per cent is 'excess' precipitation.

Normal rainfall is critical for India's agricultural landscape, with 52 per cent of the net cultivated area relying on it. It is also crucial for replenishing reservoirs critical for drinking water, apart from power generation across the country.

Rainfed agriculture accounts for about 40 per cent of the country's total food production, making it a crucial contributor to India's food security and economic stability.