Gerry Murphy of Met Éireann forecasts on RTÉ.
Met Éireann says freezing temperatures have raised the risk of snow in the southern half of Ireland and a freezing night will make for icy roads.
The forecaster's latest update on the cold snap warns that the freezing weather will last through the weekend.
In his bulletin after the RTÉ news on Thursday night forecaster Gerry Murphy said a very cold night is set to include sleet and snow mainly in south Leinster and Munster counties but mainly on high ground.
The snow will clear overnight but temperatures will not rise due to a severe frost - dropping to -5 degrees in places making for hazardous travelling conditions in the morning.
It will stay cold on Friday but be brighter.
Mr Murphy said the cold conditions would persist right through to Sunday with the possibility of wet and windy weather sweeping in on Monday.
"So overall the weather staying very cold and unsettled in general for the coming days," he said.
A Status Yellow snow ice weather warning remains in place until Sunday. Met Éireann's website forecast says it temperatures will rise to mild levels late on Sunday but temperatures could drop significantly after dark.
WEB FORECAST BELOW
TONIGHT - THURSDAY, JANUARY 31
Very cold and blustery tonight with scattered outbreaks of rain, sleet and snow. The snow will occur mainly over high ground giving accumulations, but is also possible at lower levels, especially inland. A clearance will follow from the north later in the night and the wintry precipitation will become confined to south Munster by dawn. Widespread severe frost and hazardous icy stretches developing as temperatures fall to between zero and -5 degrees in strong easterly winds.
TOMORROW - FRIDAY, FEBRUARY 1
Frost and ice will be widespread on Friday morning and will linger in some areas throughout the day. Most areas will be dry with sunny spells, but a few light wintry flurries are possible, mainly in northern and eastern coastal areas. Maximum afternoon temperatures ranging 2 to 5 degrees at best. Winds will back northerly and ease.
OUTLOOK: Feeling raw for a time, with extremely frosty nights and widespread icy conditions. Some wintry showers still around, but overall a lot of dry weather, with lots of bright winter sunshine too. Becoming milder during Sunday and Monday, but changeable and unsettled with rain at times.
FRIDAY NIGHT: Overall dry and clear but well scattered wintry showers will occur too. Extremely cold with a widespread severe frost and ice, in a light northwest breeze. Lowest temperatures -2 to - 5 degrees Celsius, but even colder over lying snow.
SATURDAY: Frost and ice slowly clearing, with dry, bright sunny weather for much the day. However, some cloud will build across Atlantic counties in the afternoon. Highs of 3 to 6 C., in mostly light northwest breezes. Bitterly cold overnight with lows of -3 to - 5 C., generally, but lower over snowfields. There will be a widespread severe frost for a time too, with icy roads. But later in the night, clouds will stream in off the Atlantic bringing some rain, possibly preceded by a little sleet and temperatures should rise in the western half of the country.
SUNDAY: Early frost in northern and some eastern areas soon clearing. All areas seeing some rain for a time, with a possibly little sleet in northern areas. But it should dry out for the afternoon. Moderate southwest breezes will veer westerly later. Afternoon highs of 5 to 9 degrees Celsius (north to south). Frost early Sunday night but milder later with rain in all areas.
MONDAY: Mild, with highs of 7 to 10 C, but some rain also in the morning. But this is expected to clear for the second half of the day.
Still cool at night with frost in places.