The Met Office has issued a yellow alert for rain, which it said will be persistent and heavy throughout the weekend.
Residents of Mid Ulster are being warned this could lead to very difficult driving conditions and may cause some localised flooding in westerly areas.
“A frontal system containing a moist west to southwesterly airstream will become slow-moving over Northern Ireland during this period, before clearing away during Sunday evening,” it reported.
“There will be some heavier outbreaks but it will be the persistence of the rainfall which will lead to some minor impacts.
“This will be mainly from standing water with amounts generally 20 to 40mm, while locally exceeding 60mm in the west.”