Thousands of people are without power and many flights have been cancelled as Storm Desmond makes landfall.
The power outages are mainly along the west coast where a Status Red rainfall warning is in effect.
In total almost five thousand properties are without electricity supply in Kinsale and Clonakilty, Co. Cork, Co. Mayo and North Dublin.
Met Eireann issued the alert for areas of Connacht as well as counties Donegal, Clare, and Kerry with accumulations of up to 70 millimetres expected.
Flights heading in and out of Dublin Airport, Cork Airport, Shannon Airport and Farranfore Airport are delayed or cancelled.
Meanwhile, the Road Safety Authority is urging motorists to avoid any unnecessary journeys as severe flooding may affect many routes.
