Met Eireann has issued a severe weather alert tonight for most of the south of the country.
Severe thunderstorms accompanied by some heavy downpours have been forecast to continue this evening and tonight over Cork, Waterford, South Tipperary, Kilkenny and parts of Carlow and Wexford.
Rainfall amounts could reach 40 to 60mm in places by the end of the night.
The A&E and X-ray Departments at Cork University Hospital were closed until further notice due to flooding this afternoon caused by heavy rainfall.
The Southern Health Board advised people in need of A&E services to go to Mercy University Hospital, South Infirmary Victoria Hospital or to visit their local GP.
Teams were put in place to clean up the flooded areas and the hospital's technical staff were assessing the damage.
An electrical storm caused flash flooding in Cork city earlier.
The Cork City Fire Service has been inundated with reports of flooding and earlier had units at five different locations in the city.
In the county, gardaí in Cobh reported a lot of surface water on Fota Road, and advised motorists to avoid the area.
