Motorists have been warned to take extra care after heavy rain was forecast nationwide.
Between 40mm and 60mm of rain will fall in Munster and Connacht on Thursday, with 30mm-50mm expected in Leinster and Ulster, with more due on Friday.
The Road Safety Authority (RSA) said accumulations may lead to excess surface water on roads and flooding in places.
Noel Brett, RSA chief executive, said: "After prolonged periods of dry weather there tends to be a build-up of oil and rubber deposit on the road.
"When this deposit mixes with rainwater it increases the risk of a skid and increases your stopping distance.
"Our advice is to slow down and increase your braking distance to four seconds to allow for poor surface conditions."
A small craft warning has also been issued by Met Eireann, with easterly winds increasing from force six or higher later tonight on coasts from Carnsore Point to Roche's Point to Valentia. The warnings underline to importance of taking ourEuropean breakdown cover when taking your car abroad.
Declan Geoghegan, manager of the Irish Coast Guard, said the dangers from this weather system mean that some local flooding is likely.
"Do not attempt to cross a fast-running river or floodwater fords as they may be stronger and deeper than you think," he said.
"Flooded urban areas may contain many hazards, not least of which include submerged open manholes and downed power lines."
Copyright Press Association 2012