Monsoon sets in over Kerala, northeast: IMD

New Delhi: Southwest monsoon has set in over Kerala and advanced into most parts of northeast India including Nagaland, Manipur, Mizoram, Arunachal Pradesh and most parts of Tripura, Meghalaya and Assam on Thursday, said the India Meteorological Department (IMD).

Normally, monsoon sets in Kerala on June 1 and advances over most part of northeast India by June 5. However, this year it has set in over Kerala two days before the normal date and six days before the normal date over northeast India.

It has also advanced into most parts of Lakshadweep area, most of south Arabian sea and some parts of central Arabian sea and south Tamil Nadu. The timely arrival of monsoon is good for agriculture as most of the kharif sowing takes place in the month of June and July.

The southwest monsoon provides about 70% of India's yearly rain and is vital for the agriculture sector that contributes significantly to the country's GDP and supports over half of its 1.4 billion population.

It is also important for replenishing reservoirs, which have been running low this year, to cater to needs of drinking water and industrial usage.

With the onset of monsoon northeast India will experience heavy to very heavy rainfall for the next four to five days. The prevailing heat waves to severe heat wave conditions over northwest and central India are likely to reduce gradually.

Rainfall during the four-month-long monsoon season, starting from June to September, is expected to be 106% of the long-period average (LPA) with a 4% margin of error, according to the weather office's second forecast. The southwest monsoon seasonal rainfall over the Monsoon Core Zone, comprising most of the rainfed agriculture areas in the country.

The seasonal rainfall is most likely to be above normal over central India and south peninsular India (over 106% of LPA), normal over northwest India (92-108%) and below normal over northeast India (less than 94%), according to the IMD.

El Nino conditions, which are known for deficient rainfall in India, are now at a moderate level and are expected to turn to La Nina by August-September, raising expectations of normal rainfall. El Nino conditions are likely to turn ENSO neutral during the early part of monsoon.

El Nino is the periodic warming of waters in the central Pacific Ocean, which led to an erratic monsoon in 2023, reducing India's food grain production by 6.1% in the 2023-24 crop year (July-June). La Nina is its opposite and favourable for the monsoon. ENSO or El Nino-Southern Oscillation relates to Pacific winds and sea surface temperatures.

The neutral Indian Ocean Dipole (IOD) conditions that prevail currently will turn positive during the monsoon season, climate model forecasts indicate, which points to generous rainfall.