Western Disturbance J-4 will approach the the Northern Parts of the Sub Continent from 19th as mentioned.
All regions of Pakistan are expected to get showers, with snow in the North on the 20th (Sunday)
Karachi will get moderate rains , maybe thunder on Sunday. Day temperatures expected to drop on Sunday. After Sunday, day and night will be cooler with the minimum dropping 3//5c .
North and Western India in for another cold spell...Gujarat will get colder too...
Kashmir/H.P. will get rain/snow this Sunday 20th thru Tuesday 22nd.. Wintry rains are likely in Punjab, Haryana, North Rajasthan , parts of Kutch,, parts of M.P, West U.P. and Uttarakhand.
New Delhi will get rains on Monday and Tuesday. Rains could linger on for another day on Wednesday. Cooler weather next week, with the day around 16/17c on Wednesday.
Mumbai expecting another cold spell next week...
Mumbai: Temperatures start dropping from Monday 21st.
Tuesday 22nd/Wednesday 23rd expected to be cooler in the day, around 28/29c, and nights around 13/14c.
Pune also expected to cool from Monday. On Tuesday and Wednesday, we may see the day dropping below 29c again, and nights around 9/10c.