A status yellow rainfall warning has been issued for nine counties.
The alert affects all of Connacht, as well as Longford, Donegal, Clare and Kerry.
Rainfall Warning.
Level: Yellow.
For Connacht, Longford, Donegal, Clare and Kerry.
Valid: 4am Wednesday to 4am Thursday.https://t.co/ozrQHtoOkt pic.twitter.com/x6mpFQbrYo— Met Éireann (@MetEireann) February 18, 2020
It will become valid from 4 o'clock tomorrow morning and remain in place for 24 hours.
Met Eireann is forecasting heavy rainfall during that period, with 25 to 40 mm expected.
Forecasters say "Localised flooding is likely as ground is saturated at the moment and river levels are elevated following recent heavy rainfall."