A New Zealander in Galway says the city is eerily quiet as locals close up shop in preparation for Storm Ophelia.
A national warning is in place for the whole of Ireland while the monster storm tracks northeastwards.
Three people have been killed as hurricane-force winds continue to batter the country and head towards the UK.
A woman in her 50s died after a tree fell on her car in West Waterford, while her passenger, a woman in her 70s, was injured.
A man in his 30s died in a chainsaw accident in Cahir, Co Tipperary, after trying to remove a tree downed by the storm. The male occupant of a car died when a tree fell on the vehicle in Dundalk, police said.
Aucklander Juliette Phillips was in the coastal city Galway where strong winds had blown seaweed over the roads. She said the streets in the city centre were near empty on Monday night.
"Nowhere is open, pretty much all restaurants, shops, and schools have been closed for the day."
"The news is blowing up warning everyone not to leave their houses - everyone seems pretty concerned."
Phillips said some stores had placed sandbags outside their doors in case of flooding.
The Ministry of Foreign Affairs and Trade said 124 New Zealanders were registered on SafeTravel as being in Ireland.
A spokesman for the ministry said there were no requests for assistance at this stage.
More than 300,000 electricity customers are off the grid amidst reports of fallen trees and power lines.
Troops had been placed on standby and many public services in Ireland and Northern Ireland were closed. Schools, government buildings and courts were among those services affected.
Met Eireann described the storm as the most powerful hurricane to have ever been this far east in the Atlantic on record, and warned there was the potential for further loss of life.
The storm could bring 50 to 75mm of rain in western Ireland and Scotland. Coastal flooding and "large and destructive waves" were expected where it made landfall.
Planes were grounded at Manchester Airport, with 20 flights cancelled and passengers warned to check ahead.
Airports in Dublin and Shannon were advising passengers in Ireland to check the latest information, with a number of flights cancelled due to severe weather.