Éireann has issued a Status Yellow - Rainfall warning for Munster, Connacht, Carlow, Kildare, Kilkenny, Laois, Longford, Wexford, Wicklow, Offaly and Westmeath
Forecasters said: "Heavy rainfall will occur during the period indicated with the potential for heavy downpours locally and during shorter intervals.
"There is potential for flooding on already saturated or waterlogged grounds."
The warning is valid from Sunday 13 October at 6pm to Monday 14 October at 11.59pm.
Meanwhile, Japan has deployed tens of thousands of troops and rescue workers after one of the strongest storms in years hit, killing at least 18 people.