Met Éireann has warned of a “possible danger to life” as it issued its highest-level wind warning for people in five counties in an upgrade to advisories for Storm Debi.
Status red wind warnings will come into effect for Clare, east Galway and south Roscommon as well as Offaly and Westmeath on Monday.
The red warning for Clare and parts of Galway and Roscommon is in place between 3am and 5am.
The separate red warning for Offaly and Westmeath follows between 5am and 7am.
People in these areas are warned of a “potential danger to life” during the storm.
Separate warnings were earlier issued for the island of Ireland as Debi is forecast to bring a new spell of heavy rain and strong winds.
It comes after parts of the island were devastated by floods during intense spells of rain from storms Babet and Ciarán.
While a yellow warning applies to every county in the country, the majority of the population are also living in areas where an orange warning applies due to the risk of “severe and damaging gusts” from Sunday night.
Met Éireann is advising it will be “very windy or stormy” due to Storm Debi across the country, accompanied by heavy rain with a chance of embedded thunderstorms and hail.
It warned there is a possibility of localised flooding, hazardous driving conditions and fallen trees.
The yellow warning for the entire country comes into effect from midnight and expires at 3pm on Monday.
The more severe orange wind warning applies to 19 counties for a more concentrated period of damaging gusts between 2am and midday on Monday.
Forecasters warn of damage to exposed and vulnerable structures, dangerous travelling conditions, damage to power lines and a disruption to services.
The warning applies to the entire counties under the red warnings, as well as Carlow, Dublin, Kildare, Kilkenny, Laois, Longford, Louth, Meath, Wicklow, Cavan, Monaghan, Kerry, Limerick and Tipperary.
Various marine advisories also apply to coastal waters, including a red warning for westerly winds reaching violent storm force 11 between 2am and 5am from Valentia to Loop Head to Slyne Head.
The National Emergency Co-ordination Group (NECG) scheduled a meeting for Sunday afternoon in preparation for the arrival of Storm Debi.
The UK Met Office has issued a yellow wind and rain warning for all of Northern Ireland on Monday.
It said heavy rain and strong winds due to Storm Debi may bring disruption and flooding to parts of the region.
It advised people to be aware that homes and businesses could be flooded and there could be disruption to bus, rail and air travel.
The agency also warned that fast-flowing or deep floodwater and flying debris could cause a danger to life.
Power cuts are also possible.
The warning comes into effect at 3am on Monday and applies until 2pm.