Parts of Ireland will experience flooding and hazardous driving conditions as "torrential" rain is due to fall on Thursday.
The bleak forecast forced Met Eireann on Wednesday to issue a 39-hour long rainfall warning for 20 counties - in the middle of June.
Some areas will also get isolated thunderstorms at times on Thursday.
And a long period of widespread heavy rain is expected later in the evening.
A spokesman said: "Heavy showers and isolated thunderstorms will occur in places during the period.
"While some areas will miss the showers where they do occur there will be some torrential downpours, localised flooding and hazardous driving conditions.
"A more prolonged and widespread period of heavy rain will occur later on Thursday."
The Status Yellow warning is in place for Leinster, Cavan, Monaghan, Donegal, Leitrim, Roscommon, Sligo, Tipperary and Waterford.
The alert will expire at 3am on Friday.
Met Eireann is predicting some bright spells and highest temperatures of 16C to 20C.
But a band of rain in the Irish Sea looks set to sweep across the country later today.
The spokesman said: "Mostly cloudy with mist or fog patches at first.
"A few bright spells and scattered showers will develop through the middle of the day with some heavy thundery downpours.
"Prolonged rainfall, heavy at times, will extend from the Irish Sea to Leinster, Ulster and north Connacht through the evening hours.
"Maximum temperatures of 16 to 20 degrees in light variable breezes."
