Southwest Monsoon withdrawal date has been revised from September 1 to September 17 from the year 2020. Although Southwest Monsoon withdrawal was delayed by more than 10 days and commenced from September 28.
The withdrawal of Southwest Monsoon 2020 was rapid between September 28 and October 6. After that, a series of low-pressure areas developed over the Bay of Bengal halted the Southwest Monsoon 2020 withdrawal. On and off rain and thundershower activities continued over many parts of the Centre and East India. Easterly humid winds continued from the Bay of Bengal. After remaining stagnant for around 15 days, Southwest Monsoon 2020 today has withdrawn from most parts of East India as well as Central part of the country. Southwest Monsoon 2020 withdrawal line is passing through which Cooch Bihar, Shantiniketan, Ranchi, Pendra Road, Mandla, Narsinghpur, Indore, Vallabh Vidyanagar, and Porbandar. Now conditions are becoming favourable for the complete withdrawal of Southwest Monsoon 2020 in the next 3 to 4 days. An anticyclone is expected to develop over Central part of the country leading to northeasterly winds over the Bengal of Bengal by October 27 or 28.
Usually, Southwest Monsoon withdraws completely by October 15. And the normal date for onset of Northeast Monsoon is around October 20. Unlike Southwest Monsoon, area of impact of Northeast Monsoon is comparatively less and covers only 5 Meteorological sub-divisions such as:
1. Tamil Nadu, Puducherry & Karaikal
2. Kerala & Mahe
3. Coastal Andhra Pradesh & Yanam
4. Rayalaseema
5. South Interior Karnataka.
One of the important criteria for the commencement of the Northeast Monsoon is easterly winds over Tamil Nadu coast between the surface and 5,000 feet. Most probably, this criterion will be met by the October 27 or 28, paving way for the commencement of Northeast Monsoon.