A status yellow advisory warning has been issued for Donegal.
The warning is valid until 11pm on Thursday.
Met Éireann say on Monday, Tuesday and Wednesday, there will be heavy showers or longer spells of rain at times over Ireland with flooding likely in places, as soils are saturated and river levels are high.
While later on Wednesday and on Thursday, Storm Ciaran will bring falls of heavy rain and strong winds.
People are also advised to prepare for poor visibility and dangerous driving conditions
