Seasonal Monsoon Dynamics Heading South

Weather Update

As we head to the last few days of the year one starts looking for signs of change in Monsoon dynamics. In the past at COMK we have mentioned many times how Monsoon Dynamics are similar to large scale Sea Breeze.  During Northern Hemisphere Summer with the heating taking place in Asia, Northern America, Africa the summer monsoon happens in June to September.  Similarly during Southern Hemisphere Summer the heating takes places over the Australia / Southern Africa creating Monsoon while the Northern Hemisphere sees its winter.  

The Animated Gif showing the Global Rainfall pattern by months will give a clear indication of how the monsoon dynamics move between the Tropic of Cancer & Capricorn during the respective summers over Northern & Southern  Hemisphere.  The retreating phase between Indian Summer Monsoon & Australian Summer Monsoon creates Northeast Monsoon for Tamil Nadu & some parts of Peninsular India. 

A couple of our earlier posts on this by us will also give a clear idea on how the monsoon dynamics work and also how Monsoon dynamics helped the growth of not only Maritime Trade of the olden days but also the expansion of empires like Cholas over the Southeast Asian region.  

https://chennairains.com/monsoon-dynamics-set-for-seasonal-shift-towards-southern-hemisphere/

https://chennairains.com/indian-monsoon-beyond-weather/

During Cyclone Phethai’s evolution we had also seen the development of another Tropical Cyclone to the south of Equator.  This has now become a Major Cyclone “Kenaga” showing annular structure this system now is packing wind speeds in excess of 200 km/h.  If one were to observe at the satellite image we can notice another area of disturbance brewing not far away from Mauritius.  Models indicate this disturbance to intensify into another Major cyclone and possibly have a close brush with Mauritius in the coming days.  To the contraty North of Equator we see a large area of unstructured disturbance in the form of a “Trough of Low” which pretty much sums up what is ahead.

While spells of rains are likely to continue on and off it appears looking at  how the Cyclone season has picked pace over Southern Hemisphere the Northeast Monsoon or Retreating Monsoon is in the last days of its retreating phase for the current year. This would mean in the days to come the rains will start getting limited to extreme southern parts of Peninsular India & Sri Lanka as we get towards the New Year