High winds have caused disruptions to electricity wires and motorists are advised to be aware of wind-blown debris as Storm Deirdre hits the country.
More than 4,000 homes are currently without power in the Glengariff area of Cork with ESB technicians currently working to repair the fault.
Emergency services - and ESB teams - are on standby to assist as two further Met Eireann weather alerts come into effect this afternoon.
Met Éireann issued a nationwide Status Orange wind warning as parts of the country are set to be battered by gusts of up to 130km/h.
The nation woke up to widespread rain this morning, but it has become heavier, particularly in south and south west counties, with spot flooding already reported in the southern region.
AA Roadwatch has warned motorists to take extra care on the roads as spot flooding has been reported in Waterford, Kilkenny and Cork.
There is the potential for "severe and hazardous" conditions with western and southern counties set to feel the force of the wind from the late afternoon.
However, stormy conditions with "disruptive and damaging" gusts will track north and eastwards during the evening and early night.
..... for a few hours later this afternoon in parts of Munster and Connacht and these severe winds will transfer to northern and eastern counties during the evening and early tonight. Afternoon temperatures of 7 to 12 degrees Celsius pic.twitter.com/lQHCAhTqeU— Met Éireann (@MetEireann) December 15, 2018
The Status Orange is in place from 3pm until midnight tonight.
Met Eireann warns: "A developing depression (Storm Deirdre) will track northeast over Ireland during Saturday afternoon and evening and will bring wet and windy weather to all areas.
"West or northwest winds will reach mean speeds of 65km/h with gusts of 100km/h generally, with disruptive and damaging gusts to 130km/h likely for a few hours in western and southern counties in the late afternoon and transferring eastwards during the evening."
Meanwhile, a status yellow warning has already come into effect for seven counties including Dublin, Louth, Wexford, Wicklow, Meath, Donegal, Cork and Waterford.
These gusts are expected to reach highs of 65km/h and this warning is valid until 6pm this afternoon, when the orange warning for the entire island will be in place.
A Status Yellow rainfall warning is also in place as forecasters warn that heavy rain will see accumulations of up to 50mm in some places.
Mountainous areas could also see even more rainfall.
Motorists are being urged to take care on the roads and avoid driving during periods of heavy rain if possible.
"The rain will be in all areas, it's hard to specify at this point but it will be widespread heavy rain," meteorologist Harm Luijkx told Independent.ie.
"The wind will be strong mostly in the east at the beginning of the day but heavy winds will be widespread by the evening."
With severe weather forecast for this weekend, retailers are expecting a drop of up to 20pc in high street shopping on one of the biggest traditional consumer days of the year.
Richard Guiney, CEO of Dublin Town, a retail group encouraging trade in the capital, said he expects a 20pc drop in footfall across the city due to the poor weather.
"It's not great timing to have a downpour of rain and strong wind on the second to last Saturday before Christmas," Mr Guiney said.
"This is one of the biggest shopping days of the year for Christmas. We will see footfall down by around 20pc due to the weather.
"Normally, we would see up to around 600,000 to 650,000 shoppers in the city on this day, so it's definitely a shame we expect the weather will impact this."
David Fitzsimons, group chief executive of Retail Excellence, said he expected high streets across the country to see a similar picture if the weather is bad on Saturday.
"But shopping centres which have indoor sections and shopping malls won't be impacted too much," Mr Fitzsimons said.
"I still think money will hit the tills later on, perhaps on Sunday and throughout the next two weeks."
The tens of thousands of Leinster rugby fans expected to attend the Champions Cup clash against Bath in the Aviva are being advised to check Met Éireann's website for weather updates.
Meteorologist Liz Walsh said: "At the moment, there's marked uncertainty regarding the forecast for Saturday.
"But the signals are for heavy rain accompanied by strong winds. Unfortunately we don't have the details yet to pin it down where the heaviest rain and strongest winds will occur, so we need people to keep checking the website and listening out for forecasts.
"But we expect there will be multiple hazards, though we do not expect snow. Northern England has a snow forecast but we have warmer air here in Ireland right now.".