New rainfall alert due and snow predicted for the weekend
A further 100 mm of rain is expected to bear down on the country this weekend, as communities battle against flood waters encroaching on their homes and businesses.
A Status Yellow rainfall warning is currently in place for Ireland with heavy rain expected.
However Met Eireann says it expects to issue another rainfall warning for torrential rain for much of the country tomorrow.
Snow began to fall in some parts of Ireland yesterday, especially in the north where urban areas saw prolonged snowfall.
There is snow in some areas of Belfast this morning, road users are being warned to exercise caution, particularly when travelling on untreated roads.
Snow has fallen in some areas in and around Belfast and appeared to be lying in some parts, marking the true beginning of the Christmas period for some.
Forecaster Pat Clarke said areas already affected by flooding can expect to see the worst of the weekend weather.
"Another weather system from the Atlantic is on its way bringing heavy rainfall," he warned.
"Munster, Connacht and Leinster will get most of it and Ulster might escape the worst of it.
"The areas which have had the worst of the rain will have some respite on Friday but that will change before daybreak on Saturday in places like Cork, Kerry, Clare and Galway. We have a lot of concern about this new rain band and I expect we will be issuing a rainfall warning for Saturday which will bring heavy rain to areas already flooded this week."
The rainfall alert could be Orange or even Red if, as another forecaster has warned, up to 100mm of rain falls in the period between tomorrow and Monday.
Irish Weather Online forecaster Peter O'Donnell issued an advance alert for between 50mm and 100mm of rain in already sodden areas this weekend.
"Total rainfalls of 50-100mm appear likely over the period from north Kerry to Mayo and the heavier amounts in north Clare, west Galway and Mayo," said Mr O'Donnell.
"Another advance alert may be required for heavy snow before midday Saturday in higher parts of Connacht and west Ulster."
Some areas of the country will see heavy rain today ahead of tomorrow's torrential downpours.
There will be heavy and prolonged showers in the west and north-west this morning before all areas become dry and bitterly cold by tonight.
Wet roads in many areas will turn icy overnight, which will persist in northern areas longest. Any frost will quickly disappear in southern counties as the new band of rainfall arrives overnight tonight, bringing more misery to areas already hit by floods.
Mr O'Donnell said around 40mm of rain could fall in western counties overnight Saturday into Sunday.
And there will be more rain on Monday, with winds gusting up to 110kph, which could trigger another wind warning alert.
"A further outlook becomes rather uncertain, with guidance beginning to split into two different evolutions," said Mr O'Donnell.
"One that seems more likely is for continued very mild weather in mainly southerly winds, occasional further rainfalls and highs generally above 10C.
"The other scenario is colder, although not generally below normal, and with longer dry intervals."