'Don't go out after 4pm' - country on red alert as deadly blizzard sweeps in
Do not go outside today after 4pm - that is the stark advice from officials, who have warned anyone venturing out in the blizzard is risking their lives.
Forecasters are predicting accumulations of snow of up to 25cm today.
This will be combined with high winds, making conditions treacherous.
The impact is predicted to be the worst winter weather since snow storms in 1982.
Taoiseach Leo Varadkar called on people to "heed the warnings".
"We are in red alert. Everybody should stay indoors," the Taoiseach said.
In an "address to the nation", Mr Varadkar said there is a real risk to life over the next 48 hours.
He added that children should be allowed to enjoy playing in the snow, but by this afternoon, Leinster and Munster need to enter shutdown.
He described the expected blizzard as a "total whiteout".
"I'm confident we are as prepared as we can be," he said.
Transport Minister Shane Ross described the "drama of the situation" as "almost unprecedented".
"It represents a real challenge to people. People must stay at home," he said.
Appeals have been made for people to check in on elderly neighbours and to report sightings of rough sleepers.
Ryanair cancelled all flights to and from Dublin Airport for the rest of yesterday as a result of the snow, which had swept into Ireland overnight.
Schools and third level colleges will be closed today and Friday across counties in Leinster. Creches and childcare facilities were also told to shut.
Dublin Bus, Irish Rail and Luas services in Dublin and surrounding counties are also being cancelled today.
Among other services severely disrupted were hospital appointments.
Ambulance and fire crews will have to be taken off the roads in some areas for a period at the height of the blizzard.
The Herald has confirmed through senior sources that contingency plans are being put in place for emergency services - but some will not be able to operate for periods today and Friday.
The Defence Forces and Coast Guard are being called in to deal with the most severe incidents.
"Emergencies will be dealt with depending on severity. People need to be sensible about any call-outs they make," a source said.
A number of shows have had to be cancelled, including The Stranglers, who were due to play the Olympia tonight. The gig has been rescheduled for April 7.
Lidl will be closing all of its stores across Leinster.
The budget supermarket said it will be closing its doors from 3pm until 1pm tomorrow.
Tesco Ireland said that its stores in areas covered by the red weather alert will have limited opening hours over the coming days.
A spokesperson for Arnotts department store said that it will be closed today due to the serious weather warnings.
"The safety of our team members and customers is our priority at this time," read a store statement.
Meanwhile, in a lighter response to the cold snap, festive radio station Christmas FM said it would be broadcasting for one day only today.
Met Eireann said the snow is expected to continue until the weekend, including some wintry showers on Saturday.
However, senior forecaster Evelyn Cusack said that by Sunday, warmer air from the south, generated off the back of Storm Emma, should begin to dominate and may allow a thaw to begin.