12:30pm, A weather photo from Karaikal, Tamilnadu ... "Thunder cells build up seen" ... http://ow.ly/i/71MY9 

PROBABLE RAINFALL IN [TN & AP] EAST COAST

One should NOT get confused with the prevailing EASTERLY now [270914/1047 hrs IST] .  The strengthening of SWM clouds in the Bay from SWly direction and the possible drift is due to upper winds . If this clouds move towards INDIAN EAST COAST, then there is a possibility of [heavy] rainfall in TN coast /AP coast coming perhaps from SEly direction 

 Similarly the drifting of clouds in Arabian sea to further west indicate clearing of  RAINFALL immediately  in the west coast.  

But the strengthening of SWM clouds from the winds from HIGH PRESSURE located about 2000 km SE of KANYAKUMARI  is drifted by upper level SEly winds.




The resultant wind some time may be in different direction [Northerly] 
Then rainfall course will be changing.{/?/?]

Weather Instagram at September 27, 2014 at 10:20AM

#chennai - 10:10am, scattered mini showers seen over city, suburbs. Drizzle now in Pammal zone. #weather

from Instagram

Today, the low-level circulation over S-tip Tamilnadu and W-S-W Bay near S-E,central-coast Tamilnadu persists ... http://ow.ly/i/71Lii 

This is the reason #Chennai is having a N-E monsoon style weather now !!
#Chennai - 10:20am, wind profile suggests Easterlies upto 4.8km above Sea... http://ow.ly/i/71Lk4 
#Chennai - 10:20am, scattered mini sharp showers seen over N-E,S-E(over sea) and many popping over Suburbs... http://ow.ly/i/71Lld 
#Chennai - city, suburbs Expected to get sharp showers with an odd HEAVY T shower before 3pm today !
Some are already happening !

Latest analysis show a low-level trough seen over S-E corner Arabian sea and circulation along S-E coast Tamilnadu.. http://ow.ly/i/71qdM 

Before morning...
More rain ahead for S Kerala and S tip Tamilnadu !
27-Sep, noon, evening...
HEAVY scattered rain again over W-ghats Kerala, W,S,S-central Karnataka, N,W-ghats,S,central Tamilnadu !
27-Sep...
Scattered T showers will pop over S,S-central,N-E Andhra ... http://ow.ly/i/71s7d 

India's Mars Orbiter Mission sends first images of Red Planet..  http://ow.ly/BZuK8 
we are following @MarsOrbiter

RT @aash_tvm: മൂടിക്കെട്ടി നിന്നതൊക്കെ ഇപ്പൊ മഴയായി പെയ്യുകയാണ്... Raining here at #Trivandrum @weatherofindia (4pm)

4:30pm, HEAVY T showers over S,S-central,N-E Tamilnadu, S,central Kerala, S-central Karnataka ... http://ow.ly/i/716PJ 

#Chennai - Mini showers seen over W,S-W,N-W from city at 50 to 80km.

Very less chance of T showers popping over city.

Latest analysis show that low-level circulation is over S tip Tamilnadu and in next 48hrs it'll drift West into Sea http://ow.ly/i/712TH

Due to this circulation, before morning of 27-Sep...
HEAVY scattered T showers for S,W,N,central, W-ghats Tamilnadu, W-ghats Kerala.
Today again, HEAVY T showers expected over W-ghats Karnataka, S,S-central Karnataka and #Bangalore ... http://ow.ly/i/7135Q
Today evening, midnight... T showers also expected over S,S-central Andhra.

Today, scattered T showers also expected to pop along W-ghats, W,S-W Maharastra.

25-Sep, Bangalore records 13cm

#Bangalore - 25-Sep, "Cloud burst" records 13cm.
" 90 mm in just an hour "

Bangalore: Heavy rain throws normal life out of gear ... http://ow.ly/BXHZv  ... http://ow.ly/i/712ac 
13 cm of rain batters Bangalore in 5 hours, man found dead ... http://ow.ly/BXI6l 

My intution and ensuing SWM torrential rain.

It has been observed that the Indian Ocean High near Mauritius is extra ordinarily of higher value.  This pressure anomaly is unusual.  Its teleconnection will reflect in India as we saw flooding in [1] J&K and recent flooding in Mehalaya & Assam.  I see a symmetry with this flooding and pressure anomaly. My fear is yet another torrential rain along south / SW India  I have given few surface charts and other wind profile data for reference/ comparison.  It is NOT a forecast. But it is my intuition. Veteran may please correct me, if it is wrong.

24.09.2014

25.09.2014

 This is 24.09.2014 / 16LT chart where the pressure is mounting and the below one is chart depicting 1039hPa. 
The other weather phenomenon like the trough forming near KOMORIN sea etc to give rainfall

However the Southern Hemisphere wind sinking at 30Deg South Latitude  [General Circulation] is NOT known to me.

veteran must clear my doubt

25.09.2014 /12Z winf

How ever preparedness to encounter torrential rain is also good. [it may happen or may NOT, that is different]