Ireland is bracing itself for the first icy blast of weather this winter.
Heavy snow showers will affect coastal counties in the north and north-west today, but it should stay mostly dry elsewhere. It will be bitterly cold with widespread frost in places and icy patches.
The very cold weather is expected to stay for the rest of the week, with temperatures in most places at around freezing point.
Today the lowest temperatures will range from zero to 5 degrees away from exposed coasts. Some snow showers are forecast for Dublin Airport, too.
A cold front is streaming down from the Arctic Circle, but temperatures are expected to turn milder on New Year's Day. In the meantime, drivers are warned to take care on icy roads in the next few days.
Today will be generally dry with bright spells this morning in Munster, Leinster and south Connacht.
The northerly hail and snow showers will spread southwards in the afternoon and evening. Some will be heavy, giving moderate accumulations of snow.
A complex depression in the Bay of Biscay is filling and drifting eastwards, accord to Met Eireann. In addition, a showery trough is approaching Ireland from the north, bringing a very cold northerly airflow.
On coasts from Valentia to Erris Head to Carlingford Lough, winds will vary north to north-east, backing west, Force 3 to Force 5 early today, then varying northnorth-west, Force 4 to 5.
For coasts from Carlingford Lough to Howth Head, Wicklow Head and the North Irish Sea, the wind will vary north to north-east, Force 2 to 4, backing west today, to Force 3 or 4.
For coasts from Wicklow Head to Mizen Head to Valentia and the south Irish Sea, wind will be north-easterly Force 5 or 6 and gusty, moderating Force 2 to 4, backing west today Force 2 to 4.
Wintry showers are expected in all sea areas in the south-west today.
Visibility will be generally good, becoming moderate, occasionally poor.
The outlook for tomorrow will be light to moderate mainly west to north-west winds, with further wintry showers.
Britain, meanwhile, is also bracing itself for a big chill in the run-up to the New Year. Forecasters expect snow and freezing temperatures to sweep across most of the country throughout the week.
Temperatures are not expected to rise above zero in many parts of Britain.