Several western counties will be under a status yellow rain and wind warning tomorrow, with all coastal areas to see gale force winds.
Met Éireann issued the 12-hour warning this morning for Clare, Donegal, Galway, Leitrim, Mayo and Sligo.
These counties will be under the warning from 2am Friday morning to 2pm that afternoon, with the forecaster warning of "wet and windy" conditions tonight through to Friday morning, "with strong and gusty southerly winds developing".
Heavy rainfall may cause some localised flooding, it was added.
Meanwhile, a marine warning is in place from 4am tonight as southwest winds will increase to reach gale force at times on all coasts of Ireland and on the Irish Sea. This warning is in place until 1pm Friday.
Across the Atlantic, south-west Florida has been struck by Hurricane Ian, one of the most powerful storms in US history bringing winds of 150mph.
The category four hurricane arrived just after 3pm local time on Wednesday and battered Fort Myers, where cars were submerged in flooding and power lines fell — knocking out power to two million people.
Ian dropped in strength by late Wednesday to category one, with 90mph winds as it moved overland.
Hurricane-force winds are expected across central Florida until later on today with widespread, catastrophic flooding likely, the hurricane centre said.
No deaths were reported in the United States from Ian by late Wednesday, but a boat carrying Cuban migrants sank on Wednesday in stormy weather east of Key West.
The US coastguard initiated a search-and-rescue mission for 23 people and managed to find three survivors about two miles south of the Florida Keys, officials said.
The storm previously tore into Cuba, killing two people and bringing down the country’s electrical grid.