Snow has been reported in parts of the west and northwest with other areas experiencing torrential rain and high winds.
Most of the country is under status yellow weather alerts on Thursday for either snow and ice or rain.
A snow-ice warning is in place for counties Cavan, Donegal, Monaghan, Leitrim, Mayo, Roscommon, Sligo and Longford until 8pm. A similar warning is in place for counties Clare, Tipperary, Galway, Laois, Offaly, Westmeath and Wicklow until 1pm.
A status yellow rain warning is in effect in counties Carlow, Dublin, Kildare, Louth, Meath, Wexford and Wicklow. It came into effect at 5am and covers a 24 hour period. Strong easterly winds are forecast to make the wet conditions worse.
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The UK Met Office has issued a snow and ice warning for all of Northern Ireland from 9am on Thursday to 6am on Friday.
Weather radar pictures on Thursday morning show snow falling in Northern Ireland, Donegal and parts of Sligo, Leitrim and Mayo. Social media pictures show snow lying in parts of those counties, though it is likely to clear by the afternoon.
There is heavy rain at present in the Greater Dublin area and in counties Wicklow, KIlkenny, Wexford and Carlow.
Transport Infrastructure Ireland (TII) is reporting heavy traffic on all main routes into Dublin city and on the M50 southbound where an accident at J3 is adding to the traffic volumes arising out of the bad weather..
Any snow that falls will melt eventually though with temperatures of between 2 to 5 degrees over the northern half of the country and 5 to 10 degrees further south, in fresh and gusty easterly winds.
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