It comes into effect this evening.
A status yellow rainfall warning has been issued for the five counties on the south and west coasts.
The alert will be in place from 6pm this evening until 6pm tomorrow evening (Wednesday) for Galway, Mayo, Cork, Kerry and Waterford with up to 50 millimetres of rain possible.
Status Yellow - Rainfall warning for Galway, Mayo, Cork, Kerry and Waterford
Valid: 18:00 Tuesday 10/11/2020 to 18:00 Wednesday 11/11/2020https://t.co/Xg3aMJlyuS pic.twitter.com/r4dJNUXARm— Met Éireann (@MetEireann) November 10, 2020
A forecaster said: ''Through Tuesday night and Wednesday, 30 to 50 mm of rain with higher amounts in mountainous areas. Flooding in places. Reduced visibility and hazardous driving conditions''.