Met Éireann has issued a Status Orange rain and thunderstorm warning for 16 counties, which is set to come into effect at 11pm tonight.
The warning effects all counties in Leinster, as well as Cavan, Monaghan, Tipperary and Waterford.
The forecaster said: "Heavy rainfall with embedded thunderstorms will likely cause flooding."
The warning will end at around 7am tomorrow.
The UK Met Office has also issued a Status Yellow rain warning for Northern Ireland, which will come into effect at midnight and will end at 11am tomorrow.
Status Orange - Rain and thunderstorm warning for Leinster, Cavan Monaghan Tipperary Waterford— Met Éireann (@MetEireann) October 27, 2022
Met Éireann Weather Warninghttps://t.co/Xg3aMJlyuS
Heavy rainfall with embedded thunderstorms likely to cause flooding
Valid: 23:00 Thursday 27/10/2022 to 07:00 Friday 28/10/2022 pic.twitter.com/QAY0va36p0