Weather models forecast slowdown in monsoon advancement in June

Hindustan Times

27-05-2025

The progress of the southwest monsoon which not only arrived eight days early in Kerala, but also covered large parts of the country including Mumbai on the west coast and almost all of northeast and peninsular India within two days, is likely to slow down after June 2, various models have indicated.
Basing his comments on the European Centre for Medium-Range Weather Forecasts' model, climate scientist and former secretary, ministry of earth sciences, M Rajeevan said on X that an early onset and rapid progress isn't 'uncommon', and that the 'active monsoon conditions' will continue till June 2, after which he expects a 'longer hiatus'.
His reference is to the lull or gap seen in the monsoon after the initial rush of its arrival and onset across much of India.
'In recent years, we see longer hiatus days mainly due to mid-latitude dry air intrusions. Farmers should be advised suitably. These are early indications from the models,' he added, although he caveated his comments by pointing to 'uncertainties'.
Mid-latitude dry air intrusions refer to dry air coming into India from the mid-latitudes.
On Monday, the India Meteorological Department (IMD) said the monsoon has advanced into some more parts of Central Arabian Sea, some more parts of Maharashtra — including Mumbai — Karnataka including Bengaluru, the remaining parts of Tamil Nadu, some parts of Telangana and Andhra Pradesh, some more parts of West-central and North Bay of Bengal, remaining parts of Mizoram, all of Tripura, Manipur, Nagaland, Arunachal Pradesh, and some parts of Assam and Meghalaya.
Conditions are favourable for further advance of monsoon into some more parts of Maharashtra, remaining parts of Karnataka, some more parts of Telangana, Andhra Pradesh, remaining parts of West-central and some more parts of North Bay of Bengal and remaining parts northeastern states and some parts of sub-Himalayan West Bengal and Sikkim during the next three days.
IMD's extended range forecast indicates rains over the west coast and the northeast until June 5 but a reduction in rainfall thereafter. Northwest India is largely likely to remain dry till June 19. To be sure, parts of northwest have been receiving heavy rains, mostly due to western disturbances and its interactions with cyclonic systems in seas on either side of the country.
HT reported on Saturday that the southwest monsoon made onset over Kerala on Friday, arriving eight days before its normal June 1 date and marking the earliest arrival since 2009.
The May 24 onset is in line with IMD's prediction of May 27 arrival and represents the fifth earliest monsoon onset in the last 55 years. The earliest recorded onset was May 18 in 1990.
'Yes, the monsoon surge will continue until June 1-2 and may cover northeast India, parts of West Bengal and East Bihar. On the western side, it may reach up to Mumbai or up to south of Mumbai. After June 1-2, monsoon may subside. Decent rain may continue over the west coast and northeast India. However, the rest of the country may receive isolated rain for at least the next 10 to 12 days,' said Mahesh Palawat, vice president, climate and meteorology at Skymet Weather.
IMD will issue its updated long-range forecast (LRF) for monsoon season and outlook for June on May 27. Monsoon rainfall during June to September, over the country is likely to be 'above normal' at 105% of LPA with a model error of ± 5%, IMD has said in its long range forecast in April.
'During the first week, monsoon conditions are likely to be active. We will update soon about the conditions thereafter,' said M Ravichandran, secretary, ministry of earth sciences.