Post Monsoon cyclone season-2021 is ending on a submissive note with no more storm likely in this month. Otherwise, year 2021 is finishing as a normal season churning total of 5 tropical cyclones with intensity varying from a cyclonic storm to extremely severe cyclonic storm. Though, there are no official bounds as such for cyclones to form in the Indian seas but predominantly the cyclone seasons run between March-June and October-December. Generally, the northeast monsoon season is more active than the former.
This year made an exception of having 2 storms in September, one each over Bay of Bengal(Gulab) and Arabian Sea( Shaheen). Actually, Shaheen was a continuation of Gulab, which after emerging over Arabian Sea as depression, intensified in to a severe cyclone. While Gulab made landfall about 20km north of Kalingapatnam ( Andhra Pradesh), Shaheen spared the Indian coastline and struck northern Oman coast.
The frequency of cyclonic storms in the Indian seas decrease in December. Since 2006, only 2016 witnessed 2 storms during the month: Vardah, a very severe cyclonic storm making landfall as a cyclonic storm over Coastal Andhra Pradesh/Tamil Nadu and Nadah, a cyclonic storm weakened before making landfall over Tamil Nadu. Most of the storms in December weaken before making landfall with an exception of ‘Thane’ in 2011 which struck between Cuddalore and Puducherry on 30th December as very severe cyclonic storm. Seven of these years since 2006 : 2006, 2007, 2008, 2010, 2012, 2014 and 2015 did not observe any storm in December. Also Ockhi, the lone storm in 2017 did not make any landfall over the Indian coastline.
This year, Cyclone Jawad in the 1st week of December also weakened before the landfall. Inter Tropical Convergence Zone (ITCZ) is lying close to the equator over North Indian Ocean. Also, there are no storms likely over the West Pacific Ocean over next 10days. These are the two major basins for generating storms over the Indian seas. Oceanic conditions do not favor for cyclogenesis in the Indian seas in the remaining part of northeast monsoon. The curtains will get drawn shortly for both, Northeast Monsoon and Post Monsoon on 31stDecember 2021.