S-E corner of Bay is having a weak low-level circulation.
An easterly wave is expected to travel West along with this circulation in 4 days

This easterlies can bring HEAVY rain for Srilanka and scattered rain for Tamilnadu coast, Chennai on 16,17,18-Jan.. http://ow.ly/i/8czrD 

Cold North India today morning..
Amristar, Bundi (Rajasthan) = 3 C
Lucknow, Jaipur, Delhi = 7 C
Dehradun = 5 C

Due to FOG, day temps across N India continue to be well below normal...
Delhi = 12 C (-9)
Hissar = 13 C (-8)
Allahabad = 15 C (-8)

Today morning in East India, Sundargarh records a low temp of 6 C.
In S India, Adilabad = 8 C.

Tamilnadu, Chennai .. continue to have warm days and mild morning around 22 C.
During next 2 or 3 days, the day and night temps over N,central Tamilnadu is expected to dip by 1 or 2C.
Chennai can expect a 20/21C morning

A good W.D system is expected to reach Pakistan and affect N,N-W India from Tuesday ... http://ow.ly/i/8cyEb 
During next 3 mornings, N-central,central,East India will continue to be COLD .!
From Monday morning, the min,max temps over N,N-W,N-central India will have above normal temps due to W.D.. http://ow.ly/i/8cyR0