ESB crews are working on restoring power as up to 140,000 homes and businesses are without power.
Fallen trees on overhead lines are the main issue following high winds.
Most of the outages are along the west coast with some in Dublin.
The worst impacted areas are Cavan, Sligo, Galway, Thurles, Castlebar, Tralee, Portlaoise, Mullingar and Dundalk.
11am update : ESB Networks crews are working to restore power to 140,000 impacted by Storm Ali latest info here :— ESB Networks (@ESBNetworks)
Please report any damage to electricity infrastructure immediately by calling 1850 372 999
The second day of the National Ploughing Championships has been delayed further due to Storm Ali.
It was due to open around 11am but organisers are still meeting to assess the situation.
A final call on whether the event will go ahead today will be made at midday.
It is only the second time in its 87-year history that the farming festival has been delayed because of extreme weather.
10.30am update: peaked an hour and half later than expected. Plan is now to open gates for 12noon. #— National Ploughing (@NPAIE)
Due to Storm Ali, there are line closures in on the following routes.— Iarnród Éireann (@IrishRail)
Dundalk - Drogheda
Carrick on Shannon - Boyle
Clara - Tullamore
Crews are on route to clear lines, expect delays. Update to follow.
High winds due to will have an impact on the flight schedule today. Some flights already cancelled. Please check with your airline before coming to the airport. Departures info here . Arrivals info here .— Dublin Airport (@DublinAirport)