A status red snow-ice warning has been issued for all counties until 3pm on Friday.
Storm Emma will arrive in the southern part of the country this afternoon and collide with the Beast from the East, causing extremely hazardous weather conditions.
Blizzards are likely along with heavy snow and strong easterly winds.
All schools and third level institutions will be closed today and Friday.
The National Emergency Coordination Committee is asking everybody to be safely indoors by 4pm today.
Bus Éireann and Dublin Bus aren't operating services today, while there are limited trains running up until lunchtime.
Irish Rail staff were clearing and de-icing points overnight.
Meanwhile, Aer Lingus and Ryanair are warning passengers of severe disruptions to flights. They're urging customers to check the status of their flights before travelling to airports.
