Waterlogged communities are on renewed flood alert amid fears that more than 50mm of rainfall could hit parts of Ireland over the next 36 hours.
However, Dublin will avoid the worst of it over the coming days.
After a weekend washout, Ireland faces another week of unsettled weather with rain predicted for the next four days.
Met Eireann issued a weather advisory for heavy rainfall from noon on Saturday until 6pm tomorrow. The advisory covers Connacht, Longford, Offaly, Westmeath, Cavan, Donegal, Clare, Cork, Kerry, Limerick and Tipperary.
From Saturday night until tomorrow morning, some areas could see as much as 50mm of rainfall, with the heaviest remaining showers coming today and tomorrow.
It is grim news for flood- hit householders, traders and landowners hoping for long-overdue relief from the deluges they have endured for seven weeks.
Gardai and the Road Safety Authority (RSA) have warned motorists to drive with care.
Atlantic weather fronts are expected to bring substantial amounts of rain over the coming days.
"The rain will be heavy in places on Monday with a risk of flooding, especially in parts of Munster, Connacht and west Ulster," a spokesperson said.
Dublin will avoid the heaviest rainfall and will also enjoy the best of the limited spells of sunshine over the next week.
While today will be marked by heavy showers, tomorrow will prove to be a bit brighter, although there will still be wintry rain showers.
Temperatures could rise to as high as 14C.
Wednesday will be cold and windy with a risk of showers and possibly hail.
Thursday will also be a cold day with sunny spells and scattered showers, several involving thunder.