There is very little rainfall activity in store for the next 5 days in the Sub_continent, 20th -26th December:
Prominent , among the meager action will be
1. An easterly wave, weak, and with an UAC embedded in ti moves across Sri Lanka, Westwards from the 21st December to 24th December. Precipitation from the wave will graze through the Southern TN regions. Heavy rains in Sri Lanka from 22nd for a couple of days.
A few showers for Chennai in this period.
2. A weak WD crosses through Northern Pakistan (extreme North) and Kashmir on the 24th.
more details in vagaries..