A status yellow rainfall warning is now in place for four eastern counties in Leinster.
Met Eireann has issued the warning for Dublin, Louth, Wicklow and Meath.
It's valid from midday today until noon tomorrow.
The national forecaster says persistent showers will lead to rainfall accumulations of 25 to 35mm.
The RSA has this advice for people who may have to drive while the warning is in place.
ðŸ“ŒDublin, Louth, Wicklow, Meath
ðŸŒ§ï¸Persistent showers will lead to rainfall accumulations of 25 to 35 mm
ðŸ“…Tuesday 20 - Wednesday 21 November
— RSA Ireland (@RSAIreland) November 19, 2018
Meanwhile, The AA advises that drivers slow down and leave a safe distance between themselves and the vehicle in front when driving on wet roads.
Dublin Fire Brigade is also urging resident's in affected areas to sweep away fallen leaves to stop drains from flooding.
25-35mm of rain is expected during the Status Yellow Rain Warning. Clearing leaves from around drains can prevent spot flooding. Is the drain outside your home or business blocked? Sweep the leaves away, however never place your hand inside the drain. pic.twitter.com/zIbqCT1dGQ
— Dublin Fire Brigade (@DubFireBrigade) November 20, 2018