SNOW is expected to blanket many parts of the country with blizzards, icy roads and damaging gusts of winds forecast.
Motorists have been warned about the dangers from widespread black ice as temperatures drop below zero.
Met Eireann issued an orange alert for the first time yesterday morning as part of a new international coded traffic-light system ranging from green to red for grading weather events.
An orange alert mean gusts of up to 130kmh and "significant falls of snow" likely to cause accumulations of three centimetres or more, with slippery paths and icy roads.
However, the forecast changed during the course of the day yesterday and by late afternoon Met Eireann downgraded the warning to a yellow alert.
The yellow alert carried a wind warning for Munster, Leinster, Connacht, Donegal, Monaghan and Cavan, with extremely high west to northwest winds and severe gusts of up to 110kmh in Connacht, Donegal and along the eastern coast of Munster.
It will be very windy elsewhere with gusts of up to 90kmh.
The strongest gusts were predicted for the west and the north.
Meanwhile, ESB crews worked throughout last night restoring power to hundreds of homes across the north-west as 120kmh winds battered the region. The worst affected areas were Ballyshannon and Killybegs, where dozens of trawlers returned to port.
And heavy wintry showers of hail, sleet and snow were expected to develop in the north of the country, becoming widespread today. There will be snow showers in many areas, mainly on higher ground but also at lower levels, the Met office added.