Met Eireann has issued a Status Red Snow-Ice Alert for the five counties of Dublin, Kildare, Louth, Meath and Wicklow.
As is the case with a red weather warning, schools in those counties are likely to close today and remain closed until the warning is lifted.
Forecasters say total snowfall up to mid-day tomorrow could reach 25 cm ,while a status orange warning has been extended to Cork, Waterford and Wexford.
It follows a very cold night, with snow showers in parts of the east, south and midlands.
The West of Ireland has escaped most of the snow showers, however, it’s on the way, with snow falling in the past hour or two in areas of Co Roscommon and moving into East Mayo.
Temperatures overnight dropped to between minus 2 and minus 5 across the West & Northwest, with minus 3 recorded at Knock Airport, and temperatures are not expected to rise above zero today.
The arrival of Storm Emma tomorrow is set to bring heavy snowfall and gale force winds.