A weather advisory warning has been issued by Met Éireann for 10 counties for "persistent and heavy rain" which could lead to flooding.
The warning is valid from around 1.30pm on Tuesday (5 October) until 6am this Saturday.
The advisory applies to Clare, Cork, Donegal, Kerry and Limerick as well as the entire Connacht province.
According to Met Éireann, a band of rain is approaching from the Atlantic and is forecast to stall over the western half of the country on Thursday and Friday.
This will lead to persistent and heavy falls in places which Met Éireann says may result in some river flooding and localised surface flooding.
The advisory will be updated by Met Éireann on Wednesday morning and further weather warnings may be issued.
The national weather forecaster said Wednesday will be cloudy and overcast, with scattered outbreaks of rain and drizzle which will be persistent at times across the west and northwest.
Longer drier spells will develop in parts later with some brighter spells breaking through and the weather staying driest in the east.
Thursday will be another dull day with outbreaks of rain that will be heavy and persistent across Atlantic counties, although there will be some brighter spells across the midlands and east where it will stay driest again.
Outbreaks of rain will continue into Friday, the heaviest of which will likely persist across Atlantic counties with the ongoing risk of localised flooding.
On Saturday, outbreaks of rain will lighten through the day.
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