"Significant" snow and ice is expected over the weekend and into next week as a weather front from Siberia descends on Ireland.
The severe weather will settle in on Saturday and will last until Wednesday at the earliest.
The wind will come from the east and north-east and will pick up moisture in the Irish Sea which is forecast to fall as snow.
The eastern seaboard from Antrim down to Waterford is likely to see significant accumulations of snow and day-time temperatures of no more than four degrees will see much of it lying on the ground.
Early indications suggest that next Wednesday may bring even further accumulations of snow as an Atlantic depression meets cold easterly air from Siberia.
The weather phenomenon which will be bringing snow and ice is a sudden stratospheric warming event which occurred in the Arctic recently. The same phenomenon brought the “Beast from the East” in February 2018 which saw the heaviest snowfalls in Ireland since 1982.
Cold airflow
A sudden stratospheric warming event can cause the jet stream to divert southerwards dragging cold easterly winds across western Europe.
Met Éireann forecaster Gerry Murphy said: "Those events do and often cause the weather patterns to adjust where we have a cold airflow coming in over Ireland. It does look like that's the situation."
A high pressure area will be situated around Greenland and Iceland and the winds will come clockwise from the east.
“We will have very cold weather for Sunday, Monday, Tuesday and Wednesday. The winds will feed in showers over the eastern half of the country and those showers will be of sleet and snow,” he said.
“As the cold weather persists, each day and each night will be colder. The showers will become wintery. A fair few of those are likely to be of snow from Sunday into Wednesday.”
Mr Murphy said temperatures during the day will not rise above four degrees and temperatures will fall to minus four at night next week. He cautioned that it was too early to "pin down a number" as to how many centimetres of snow will fall.
“That’s why we have said there will be significant accumulations, but it will be more than a few centimetres,” he stated. “I don’t want to put amounts because it is only going to frighten people at this stage. I can’t give an exact figure .”
There will be frost and ice in the west of the country, but the showers will be mostly coming off the Irish Sea and there is unlikely to be snow.
Mr Murphy cautioned that it was too uncertain to say if conditions will be as bad as they were three years ago.
However, with schools and most non-essential businesses closed, it is unlikely to bring the same levels of disruption as 2018.
