The Low in the Bay, numbered BB-13, has moved West into Orissa. BB-13, will move West, into MP, and  restricted by the high pressure in the North.
It will track thru MP and weaken along its path, 

Friday: Heavy Rains to Watch out for: Central MP. Bhopal Districts.
Saturday: Western MP and adjoining North Maharashtra and parts of Eastern Gujarat.

City Forecasts:
Mumbai: Rainfall intensity and frequency decreasing. 
Friday. Partly cloudy day. Thunder clouds building up in the Eastern sky. Chances of drifting and bringing rain in some parts of city by evening. Rain amount expected: 10-12 mms average.
Saturday/Sunday: Thundery developments in evening, otherwise partly sunny day. Light showers in the evening in some areas. Rains about 5-7 mm/day.

Pune:
Friday: Thunder showers in the evening, lesser intensity, around 10 mms. 
Saturday/Sunday: Cloudy and warm day. Almost no rains.

Chennai City: 
Friday/Saturday: Chances of a thunder shower "popping up" in some parts of the city. Regional rains upto 7-10 mms.
Sunday: Partly cloudy and warm. 

Delhi NCR: Cloudy and stuffy weekend.
Friday: Sunny, getting cloudy later in the day.
Saturday/Sunday: Cloudy day, and stuffy nights. Day temperatures around 32c on Saturday, rising on Sunday.

Kolkata: Clearing after Friday.
Friday: Remaining moisture from BB-13 will bring thunder showers in many parts of the city during the day.
Saturday/Sunday: Rains and shower intensity and frequency decreasing on the weekend.

Hyderabad: Heavy thunder shower. Saturday/Sunday: Light rain in some parts of city on Saturday after cloudy day. Sunday will be without any meaningful rains.

From Vagaries

RT @archvivekh: Raining in Ambattur! #Chennai @weatherofindia (8:11pm)

RT @archvivekh: @weatherofindia heavy rains lashing the whole of Ambattur for past hour! Woo hoo$! (8:49pm)

#Chennai - 7:36pm, moderate mini showers seen over West from city at around 40 to 60km. May push into W,S-W,N-W suburbs of city.

6:30pm, The low.mid level N Bay circulation has moved inland, now over Jharkhand, Odisha and N,central Chatisgarh http://ow.ly/i/3bYEl 
7pm, Heavy rain over E Uttarpradesh, E Madhyapradesh, central,N Chatisgarh, N,N-E Andhra, S Odisha, W,S,central,E Maharastra and Jharkhand.

12pm, #Monsoon (Saaral) rains pummelling our ghats, Mahendragiri to Naraikadu ranges ... PHOTO ... http://ow.ly/i/3bSkU 

#kolkata, yesterday and today !

#Kolkata - 11:50am, "COLOSSAL RAINS HIT SOUTH KOLKATA" and now (1:12pm) it is Clearing !

PHOTO >> This was #Kolkata yesterday (taken from https://www.facebook.com/WeatherOfKolkata) ... http://ow.ly/i/3bRrH 

DUE TO THE LOW OVER N.BAY, LAST 24 HRS HAS BEEN WET WET WET FOR EAST INDIA 
SOME OF THE HEAVY RAINFALL OF EAST INDIA IN 24 HRS ending 8:30am Today.

1. CONTAI (WB) - 188.4 MMS
2. BARIPADA (OR) - 158.4 MMS
3. JAMSHEDPUR (R) - 61.4 MMS
4. DIGHA (WB) - 45.8 MMS
5. BALASORE (OR) - 42.3 MMS
6. PURI (OR) - 38.8 MMS
7. RANCHI (R) - 38.4 
8. BASHIRHAT (WB) - 29.4 MMS
9. MEDNIPUR (WB) - 24.2 MMS
10. BANKURA (WB)- 25.5 MMS
11. BHUBANESHWAR - 23.5 MMS
12. ALIPUR (KOL WB) - 20.8 MMS
13. JHRASGUDA (OR) - 19.8 MMS
14. DUMDUM (KOL WB) - 15.5 MMS
15. PATNA (BH)- 15.9 MMS

Update on N Bay LOW and its prospects

Today, the N Bay LOW persists ... http://ow.ly/i/3bOZv 

The low, mid level circulation associated with N Bay LOW can be seen along N Odisha coast ... http://ow.ly/i/3bP3s 

There's another low,mid level circulation seen over N Karnataka and N-W Andhra ... http://ow.ly/i/3bP3s

Upper level 500hpa circulation is seen along Odisha coast... this is expected to drift S-W upto N-E Andhra in 36hrs http://ow.ly/i/3bPQ6 

The upper level circulation after drifting upto N-E,central Andhra coast in 36hrs, it is expected to move N-W into Maharastra on 22/23-Sep

GFS and NAVGEM models expect the present N Bay low level circulation to move West upto Madhyapradesh on 23-Sep.. http://ow.ly/i/3bQ3l 

During next 24 to 48hrs, rain expected to persist over W,S central maharastra.
HEAVY rain due to N Bay LOW will slowly push into most of Odisha, Chatisgarh and into E,S-E Madhyapradesh, S,E Uttarpradesh on 20,21-Sep
Heavy Showers over S,central Bengal is expected to subside from tonight ! Isolated moderate rain will persist till tomorrow evening.
Scattered HEAVY rain also expected for entire coast of Andhra and for N,N-E Tamilnadu, #Chennai during next 2 days.
HEAVY rain along S Maharastra coast, Goa, Karnataka coast and Kerala to continue for next 36hrs.. expected to reduce from Saturday !
Scattered Moderate rain expected for S Karnataka, #Bangalore and S Andhra during next 3 days !
During next 48hrs, scattered Rain expected over N,N-E Andhra... this depends on the upper level circulation's drift into N-E Andhra coast.
HEAVY rain to continue over Kerala and Karnataka coast during next 2 days !