A status yellow weather warning has been issued for all parts of the country with heavy rain and wind expected everywhere.
Many parts of the country will get more than 30mm of rain (over an inch) in the space of less than 24 hours leading to spot flooding in places.
Heavy rain will become widespread on Friday night and strong southeasterly winds will reach gale force in coastal areas.
It will rain all day on Saturday with local spot flooding as heavy rain continues through the day.
The heaviest pulses of rain will be over the north and west of the country especially Connacht and Ulster where there is a possibility that the weather warning will be upgraded to orange.
Strong southeast winds in the morning will become strong west to northwest winds in the afternoon, with the potential for damaging gusts in parts of the north later.
The forecast is for the rain to clear away on Saturday night and it will become mostly dry by morning.
Winds will veer from the south-east to the north-east on bringing a dramatic drop in temperatures on Saturday night and Sunday night.
Temperatures will be near freezing on these nights.
