Posted on Monday(16th) Night:

Monsoon Axis has slid to the Central Regions of India. The SWM is expected to withdraw from more regions by Wednesday. 
The West coast trough has activated, and an UAC is forming off the S.Konkan Coast. Due to high pressure building up in the Central India region, a Line of Discontinuity forms in the Central Mah. region . 
The Eastern End of the axis will host an UAC in the Bay by the 17th or 18th.

Tuesday 17th: Thunder storms along Konkan (interiors), Marathwada and Eastern Goa (The ghats region). Adjoining N.I.Karntaka.
Places to watch out for heavy rains: Belgaum district and Raichur District in Karnataka, South Konkan . Kurnool and Hyderabad regions in AP. 
In Maharashtra, Marathwada can receive heavy rains. (Nanded and Parbhani districts).

Wednesday 18th: Precipitation in Coastal Karnataka. Vidharbha gets thunder showers on Wednesday.
Heavy Rainfall to watch in Bellary and Gadag districts.
 Kolhapur, Solapur and Satara District can get heavy rains in some pockets. Some outer townships of Mumbai.

From vagaries

#Chennai - 6:45pm, Super T showers now seen over S Andhra.

Malout - 7:08pm, 20 kph winds after sunset with passing clouds, now clear weather and winds stopped. Today morning cloudy till 10am.

Bangalore - 12:28pm, "HOT and Humid"

#Chennai - 4:24pm, #HOT and Humid. NO cloud formations yet!

Badlapur, "Cloud burst" - evening of 15-Sep

Badlapur - Cloud Burst, 186.4mm rain till 8.30am today. 100mm was recorded in just 1hr period between 5.30pm to 6.30pm yesterday evening

Badlapur Railway Station view yesterday evening after massive rain in short period. 

Heavy rain for Kerala and W,S central Maharastra for next 2 days

Two circulations seen today, one along Goa coast and another over N Bay just south of Bangladesh ... http://ow.ly/i/3a05z 

2pm, showers seen ALL along from S Maharastra coast to S Kerala... showers popping over  Odisha and N,N-E Andhra.. http://ow.ly/i/3a0fS 

Today, the offshore trough is seen along Goa coast to central Kerala coast ... likely to persist for next 2 / 3 days http://ow.ly/i/3a0mv 

Today a strong upper level 500hpa circulation seen over W,S maharastra... expected to produce more HEAVY rain ... http://ow.ly/i/3a0uu 

During next 36hrs, HEAVY and widespread rain for Kerala, S tip Tamilnadu, Karnataka coast, Goa and S Maharastra coast.
Scattered HEAVY rain also for W,S,central maharastra, N,central,E,S Karnataka, S,W Andhra and into N,N-E Tamilnadu during next 2 days.
Scattered rain to continue over N,N-E Andhra, S Chatisgarh and Odisha during next 3 days.