Up to 4 inches of snow in places night with a further 6 to 8 inches of snow forecast between now and Friday.
The national forecaster, Met Eireann is claiming that further heavy snowfalls are expected right along the east coast from Louth down to Kildare and inland to Westmeath over the coming 72 hours.
Met Eireann will decide in the morning whether a Red Alert Weather Warning will be issued nationally.
The gardai, the AA and Met Eireann have advised motorists who have to be on the roads to take extreme care and to avoid B roads that may not be fully gritted.