Much of Cork city centre is currently under water as flooding overruns the city once again.
After the River lee burst its banks once again, much of Cork is now inaccessible.
Diversions are in place around the affected areas, which includes the South Mall, Morrison's Island, Father Mathew Street and Union Quay.
Cork city was hit by flooding of low lying areas as storm tides reached their highest point of the eight day alert period which ends on January 5.
Flooding of some city centre quays began from 5.40pm and continued after high tide at 6.15pm and was exacerbated by large quantities of surface water from heavy rainfall.
Met Eireann is warning that since ground is already wet across most of the country, heavy rain could cause flooding across much of the country.
Met Eireann forecaster Pat Clarke has said some of the highest tides of the year are expected.
Strong onshore winds will affect the south and southwest tonight, and tomorrow the northwest coast will be affected.
“Seas are going to remain high, and they’ll abate a little on Friday and Saturday but then they’re back up on Sunday and Monday,” he said.
“The councils [around the country] are issuing local warnings based on our advice”
“It’ll be dangerous even walking near the coast,” he warned.
High tides and torrential rain caused flooding throughout the country yesterday and even worse conditions are expected.
Met Eireann warned that storms with gusts of up to 120kph are expected to pound the south and west coasts from early evening as the unsettled weather of recent weeks continues.
The Atlantic seaboard is to take the brunt of the bad weather over the next 24 hours.
There is also a status yellow alert for Leinster, Cavan, Monaghan, Tipperary and Waterford with gusts of 90 to 110kph forecast and a risk of flooding in coastal areas.
A flood alert has been issued for the entire south west and west coasts - from Cork to Donegal - over the next 36 hours.
Low-lying cities like Cork and Galway are high-risk areas for flooding, Met Eireann has warned.
In the south of the country this evening, torrential rainfall and winds gusting to 120kph again caused widespread flooding across low-lying areas and in the Blackwater, Lee, Funcheon, Bandon, Suir and Shannon river valleys where hundreds of acres of farmland are now under flood waters.
Met Eireann has warned in particular that due to the high number of recent storm events, structures may have suffered unobserved damage and these will be "more than usually vulnerable to tonight's storm".
Drivers were advised to be particularly cautious, with excess surface water making many roads impassable throughout the country.
Irish Water Safety (IWS) is warning the public that to stay safe they must stay away from the edges of all waterways during storm conditions that are even more dangerous due to heavy rain, strong gale force winds and high tides.
The group warned that fast-rising flood water is very powerful and often hides the dangers of exposed drains, exposed manhole covers and submerged objects.
A spokesperson said no driver or pedestrian should take a chance passing through flooded roadways.
Parents should caution children that small flooded streams are very fast and that floodwater hides true water depths, the spokesperson added.
The Irish Brokers Association (IBA) has warned that floods could spark a rise in claims. It said that up to 50,000 buildings were excluded from flood cover because of "geo-coding by insurers".
Deemed to be at particular risk of flooding are the areas of Cork city, Dublin Basin, Clonakilty, Bandon, Fermoy, Clonmel, Waterford, Carlow and the Shannon River area.
Brian McNelis at the IBA said that flooded householders should arrange for emergency repairs to be carried out to stop any damage getting worse. They should also mark water levels on the walls for reference and photograph or video all flood damage.
In Dublin, residents were warned to stay safe if outdoors and close to coastal areas.
Marine Drive and Strand Road in Sandymount were closed due to flood threats.
Flooding was worst in Clontarf, when seawater breached the promenade wall for the first time since 2004, with much debris washed in.
Local businesses and residents have been warned that the worst could be yet to come, with tides suspected to be even higher at 3pm tomorrow than they were yesterday.
Dublin City Council has supplied precautionary sandbags for houses and businesses at risk. However, the bags will not be delivered door to door as had been done in the past and must be collected instead from Portakabins along the promenade.
Local TD Aodhan O Riordain said: "I only received the email the previous day -- and I'm the local TD."
In Wicklow, high tides washed on to the harbour in the town and there were reports of flooding on the Rathnew/ Rathdrum road and on Old Connaught Avenue in Bray.
In Cork, floods caused chaos as swollen rivers were unable to cope with overnight torrential rainfall, with Cork city, as well as Fermoy, Mallow, Bandon and Carrigaline, worst hit.
Low-lying areas of Cork city were hit by flooding after high tides at 5pm yesterdaybut the damage was not as severe as forecast.
The city will remain on major flood alert until Sunday when conditions are expected to ease.
Gardai were forced to close the Crosshaven to Carrigaline road due to flooding, with diversions being put in place.
Parts of Mallow and the Mill Road in Fermoy remained under floodwater last night.
Cork Racecourse outside Mallow, which was flooded two days ago, will undergo an inspection at 9am today to see if it can host a seven-race meeting scheduled for Saturday.
Flooding also hit roads in Bandon, Dunmanway, Clonakilty and Donoghmore.
In Galway, the road between Athenry and Turloughmore was impassable at Coolarne.
In Ennis, homeowners said they were living in fear of being forced from their homes by flooding as they were in 2009, as they braced themselves for expected high waters.
Clare County Council issued a weather advisory warning of tidal surges, gales and heavy rain, urging home and business owners to take precautionary measures.
Locals at Fior Uisce on the Gort Road in Ennis, said they dreaded the prospect of waking up to find their homes flooded again.
Funding for flood relief works for their area was approved in 2010 but nothing has been done, they claimed. Clare County Council confirmed works would be undertaken this year, but locals fear it may be too late.
By Nicola Anderson and Ralph Riegel