Why The Country Witnessing Late Monsoon Withdrawals?
Southwest monsoon was withdrawn from the entire country on 28th October 2020. The country is witnessing the delayed monsoon withdrawal dates. This is the second most delayed monsoon since 2010. In 2010, the monsoon was withdrawn on 29th October. The monsoon onset and withdrawals are recorded by India Meteorological Department since 1975.
Why the monsoon withdrawal is delayed? 2010, 2016 and 2020 are the most delayed monsoon withdrawal years. The probable reason for such delay can be anticipated with the presence of La Nina. 2010, 2016 and 2020 are under La-Nina effect. But the question is whether the Southwest monsoon withdrawal is properly anticipated or it is the change of pattern which has been failed to anticipate?
“Is weatherman is failing to anticipate the changing patterns of monsoon?”
Both monsoons can’t co-exist since the winds flow are opposite to each other. So the change in winds is gradual and can’t be drastic.
Points to consider
For the last three four years it is seen that monsoon withdrawal declared up to Dahanu and then suddenly it is withdrawn from all over country. At the same time north east monsoon started over the country.
Though it is not uncommon but still we have to think the below points forcing to declare withdrawal like this.:
(1) A low form over Bay of Bengal off south Odisha and north Andhra Pradesh coast on 9th October has played an important role. Whether it can be addressed as low of north east monsoon or low of south west monsoon.
2) Had this low form over Tamil Nadu coast this would have been called North East monsoon low.
(3) At that time north of this low there was Northeasterly wind over Bay of Bengal and over north and central India. But possibility of rain over Maharashtra and South Gujarat and southern part of Saurashtra which is not possible in case of northeast rain.
For example in 2020, by 26th October, as per IMD the withdrawal line passed through Cooch Behar, Sriniketan, Ghatshila, Keonjhargarh, Nowrangpur, Elluru, Nalgonda, Nanded, Nasik, Dahanu (as shown in figure). By 28th it withdrew from the whole country.
image source: IMD
Here are the monsoon withdrawal dates for the past 10 years:
| Year | Withdrawal Date |
| 2011 | 24th October |
| 2012 | 18th October |
| 2013 | 21st October |
| 2014 | 18th October |
| 2015 | 19th October |
| 2016 | 28th October |
| 2017 | 25th October |
| 2018 | 21th October |
| 2019 | 16th October |
| 2020 | 28th October |
