Southwest monsoon withdraws; northeast monsoon commences over peninsular India
A cyclonic circulation is likely to develop over southeast Bay of Bengal and the neighbourhood by Tuesday. It is likely to move westwards. Under its influence, a low-pressure area is likely to form over central parts of South Bay of Bengal during subsequent 48 hours. Isolated heavy rainfall is likely over Tamil Nadu, Puducherry and Karaikal during October 25 to 29.
Monsoon has withdrawn from the entire country; with the setting in of north-easterly winds, the northeast monsoon has commenced over south peninsular India, the India Meteorological Department said on Monday.
This is the seventh most delayed monsoon withdrawal during the 1975 to 2021 period. Monsoon had withdrawn on October 28 last year; on October 25 in 2017; on October 28 in 2016; on October 2019 in 2010 and October 27 in 1975. Interestingly, out of these 7 years, during recent years of 2010-2021, 5 years had monsoon withdrawal on or after October 25---2017, 2010, 2016, 2020 and 2021.
“The past ten years show that there is some delay in complete withdrawal of monsoon from the country. Southwest monsoon should withdraw from the country around October 15 and northeast monsoon should commence over peninsular India by October 20. But there is some delay. This may be linked to a prolonged summer in the northern hemisphere. It is also linked to climate change which the Intergovernmental Panel on Climate Change (IPCC) has also recognised in its latest report,” explained DS Pai, scientist and head of climate research and services at IMD Pune.
Unseasonal rain in October due to western disturbances caused flooding and landslides in different parts of northwest India earlier this month. Uttarakhand was particularly badly impacted. October rains though caused due to western disturbance, delayed monsoon withdrawal from the country provided adequate moisture for intensification of rainfall episodes, Pai said.
In Himachal Pradesh, Rajgarh recorded 8 cm, Solan 7 cm; Haryana, Chandigarh and Delhi: 3 cm; Punjab: Ludhiana-10 cm, Patiala-9 cm; in West Uttar Pradesh: Aligarh recorded 5 cm rain on Sunday.
“In view of significant reduction in rainfall activity over most parts of the country the Southwest monsoon has withdrawn from the entire country on Monday. Simultaneously with the setting in of north-easterly winds in the lower tropospheric levels, the northeast monsoon rain has commenced over extreme south peninsular India today,” IMD said.
A cyclonic circulation is likely to develop over southeast Bay of Bengal and the neighbourhood by Tuesday. It is likely to move westwards. Under its influence, a low-pressure area is likely to form over central parts of South Bay of Bengal during subsequent 48 hours. Isolated heavy rainfall is likely over Tamil Nadu, Puducherry and Karaikal during October 25 to 29; over Kerala and Mahe during October 25 to 27; over South Interior Karnataka on October 25 and 26; over Coastal Andhra Pradesh and Rayalaseema on October 28 and 29. Light to moderate, widespread rainfall with thunderstorm and lightning is likely over Kerala, Mahe, Tamil Nadu, Puducherry, Karaikal and South Interior Karnataka during next 5 days.