Tropical storm Lorenzo will bring a significant threat of damage and flooding and nowhere can expect to escape its effects, experts have warned.
The National Emergency Co-ordination Group on severe weather said while the south of the country from south Co Cork through Kerry, Clare, Limerick, Galway and Mayo are currently classified as status orange warning areas, the rest of the country could expect falling trees that could take down power lines and block roads.
"The ground is already waterlogged from rain in the past few days, combined with the fact that trees still have their leaves, making the risk of them falling greater," said Evelyn Cusack of Met Eireann.
"Even in a yellow zone, because of the time of year and the fact that the ground is saturated and the fact that the trees are in leaf, there could be trees down anywhere.
"The ground is saturated and that means some trees' roots are weakened. Status yellow is for winds of 100kph and that can cause trees to be downed," she added.
In addition, the south-west, west and north-west coasts will see large sea swells and waves driven against shores tonight.
Ms Cusack told how Storm Lorenzo is tracking north-east and transitioning from being a hurricane to a storm as it crosses from warm waters to cooler waters nearer Europe.
Strong storm-force 11 gusts - winds above 100kph - are possible as Lorenzo heads for the west coast.
"There will be very low air pressure in the storm, which means there is little weight in the air pushing down on the sea, so sea levels rise," she said.
"That, combined with high tide, onshore gale-force eight to storm-force 10 winds, and storm-force 11 winds for a time, is all pushing against the south-west, west and north-west coast, so there is likely to be coastal flooding and damage.
"It will be a short event but there is likely to be heavy pockets of rain and as the storm is of tropical origin there will be some thunderstorm activity and lightning."
Ms Cusack did not rule out status red level conditions in some localised coastal areas, while the National Emergency Co-ordination Group will continue to monitor Lorenzo with a further update to be issued this morning.
Jim Casey, from the Office of Public Works (OPW), said with high tide due around 9pm tonight there could be rising sea levels and sea swells over-topping some coastal walls.
He added sea flooding on the east coast was not anticipated but the situation was being monitored.
Advice being given to households, especially those in the status orange areas, was to ensure phones were charged in advance of the storm and torches fitted with fresh batteries.
People were urged to have their Eircode and their unique MPRN number for electricity supply to hand in case they had to report a power failure or emergency. The MPRN number can be found on your electricity bill.
People on shared water schemes that could become compromised were also advised to stock up on water, especially drinking water.
Derek Flanagan, from the Coast Guard, urged people to stay away from coastal areas, including piers and cliffs.
"Stay back, stay high and stay dry is the simple message, and be aware that if you end up in a dangerous situation you could be putting at risk the lives of the crews that have to go and possibly rescue," he said.
ESB Networks warned that power cuts were expected.
"Be vigilant. It's clear that trees will fall given the level of ground saturation; it's clear that electricity lines will come down either as a result of the winds or as a result of trees taking down electricity lines," said Derek Hynes of ESB Ireland.
"We would ask people to be really careful when they see a tree down and to be aware that there may be live electricity wires tangled up in that tree."
People are urged to monitor the media and social networks for updates from local authorities, airports, airlines, ferry companies and the emergency services as the day progresses.
Drivers are warned to be careful, particularly vulnerable road users such as cyclists, motorcyclists and drivers of high-sided vehicles.
"Expect the unexpected, such as trees and branches that could fall and block roads, and do not drive through floods," said Brian Farrell of the Road Safety Authority.