The Met Office has issued a yellow status severe weather warning of rain for Northern Ireland.
The warning is valid between 6:00pm on Friday and 9:00am on Saturday.
"Outbreaks of rain will become heavy and persistent through Friday evening and the early hours of Saturday," reads the warning on the Met Office website.
"Accumulations of 20-30 mm are expected quite widely with isolated 40-50 mm possible across western and northern hills.
"The rain will clear eastwards through Saturday morning."
The warning applies to all counties except Down and Armagh.