Met Éireann has issued a status orange weather warning.
It said high winds and possible flooding may significantly affect people in Counties Clare, Cork, Galway, Kerry, Leitrim, Limerick, Mayo, Waterford and Wexford tonight.
It said there's a strong likelihood of coastal flooding -- and added that heavy thundery downpours may lead to local spot flooding inland also.
Irish Ferries have cancelled all its Swift sailings on the Irish Sea today and tomorrow.
The Irish Coast Guard is advising members of the public to avoid exposed coasts, cliffs, piers and beaches during the current stormy weather.
Taoiseach, Enda Kenny has said he expects the Cabinet will be briefed on the extent of the damage caused by last week's flooding in the west and south west when it meets next.
There have been calls for Government funding to help with the costs of damage to homes, businesses and infrastructure.
Mr Kenny, who is leading a trade mission in the Gulf, said detailed reports on the flood damage and potential costs were needed before any decisions could be made.
Northern Ireland is also preparing for the expected storm.
Belfast City Council is making available sandbags for collection in the east of the city again today.
Around 3,000 sandbags were given out yesterday.
The measure was prompted by concern about the impact of high tides combined with strong winds and heavy rain tomorrow.
Nearly 100 flood warnings are in place in England and Wales, while 10 have been issued in Scotland.