A status orange rainfall warning will be in effect for Waterford from 4am to 8am tomorrow.
Up to 50mm of rainfall is anticipated with the potential for spot flooding and squalls as a result.
Met Eireann has updated it's weather warning to orange from an initial yellow level.
It's warning of intense rainfall for Waterford and 12 other counties, including the home of Electric Picnic - Stradbally, County Laois.
Met Éireann said local intense rainfall (50mm) is expected in Carlow, Kildare, Kilkenny, Laois, Longford, Offaly, Westmeath, Cavan, Donegal, Leitrim, Roscommon, Sligo, Waterford.
There is also a Status Yellow rain warning for all of Ireland set to come into effect at 1am. It will last until 10am tomorrow.
Met Éireann said "heavy rain will move northwards across much of the country tonight, clearing from the north and northwest on Sunday morning".
"Some torrential downpours are expected in parts, resulting in surface flooding. There is also the potential for thunderstorm activity and lightning strikes."
