Two separate Status Yellow thunderstorm warnings covering most of the island of Ireland have been issued for tomorrow.
One thunderstorm warning for 12 counties will come into place at 6am and will end at midnight.
Met Éireann issued the warning for Carlow, Dublin, Kildare, Kilkenny, Laois, Wexford, Wicklow, Cork, Kerry, Limerick, Tipperary and Waterford.
Another one for Cavan, Monaghan, Clare, Galway, Leitrim, Roscommon, Longford, Louth, Meath, Offaly and Westmeath will come into place at 12pm and also end at midnight.
The forecaster said that localised thunderstorms and slow-moving heavy downpours will lead to frequent lightning and surface water flooding.
The UK Met Office issued a similar warning for Antrim, Armagh, Down, Fermanagh, Tyrone and Derry, which will come into place at 2pm tomorrow and end just before midnight.