Met Éireann has issued an orange level rainfall warning for 15 counties overnight, including Co Laois where festival-goers are attending Electric Picnic.
The forecaster says 50mm of local intense rainfall and squalls are likely. The warning is for between 4am and 8am on Sunday for counties Carlow, Kildare, Kilkenny, Laois, Longford, Offaly, Westmeath, Cavan, Donegal, Leitrim, Roscommon, Sligo, Waterford, Wexford and Wicklow.
The national forecaster said there is a possibility of surface flooding and thunder and lightning.
Rain hit the Electric Picnic site on Friday night and Saturday morning where 70,000 were attending, many camping.
The campsites at the Stradbally festival were wet, muddy and worn down by the festival-goers walking between their tents and food stalls on Saturday morning.
The heavy rain overnight meant many attendees experienced wet sleeping bags, pyjamas, and flooded tents. On Saturday morning, groups of friends were seen attempting to re-pitch tents that had come down during the wet and blustery weather.
“I’m going home,” one woman was overheard saying to her friends while queuing for the bathroom. “I didn’t sleep at all. We were absolutely drenched. I can’t do another night of this.”
Met Éireann meteorologist Emer Flood said festivalgoers were not likely to see any respite, with even more rain to come on Saturday night.
“They’ve seen a lot of rain already so far last night, but I think tonight will potentially see a lot more rain than there was last night,” she said. “There is also a risk of thunder and lightning.
“They might get lucky, but it looks like they’re going to be right under the track of torrential falls of rain. Overnight tonight and up to about dawn tomorrow morning there will be very heavy falls.
“The good news for EP is that during the day time tomorrow it won’t be too bad, but the next spell of rain will be coming in later in the evening, around the time the headline acts will be coming on unfortunately.”
Met Éireann has also issued a yellow level rainfall warning for the entire country. It has warned of torrential downpours as well as potential thunderstorms and lightning strikes in the early hours of Sunday morning.
The yellow level rainfall warning for all is valid from 1am on Sunday until 10am.
The forecaster says heavy rain will move northwards across much of the country on Saturday night, and clear from the north and northwest on Sunday morning. It says some torrential downpours are expected in parts, resulting in surface flooding.
“There will be spells of at times very heavy rain and fairly strong winds and gales developing as well, but it is more so the rain than will be the main feature of this weekend,” said Ms Flood.
“We have a lot of rain over the northeast, and that is going to persist across parts of Ulster through the evening and into tonight. Elsewhere in the country, there have been fairly heavy showers in Munster. There was a thunderstorm in Cork earlier this afternoon.
“There will be a short period early tonight when things dry up across the country, but we do have another fairly active front approaching from the south, and there are a number of rainfall warnings in effect for that.
“We’re going to have quite a wide spread of rain moving northward across the country overnight tonight from shortly after midnight. With that, there will be some fairly intense falls of rain.
“The track for the heaviest falls of rains isn’t certain, but we know they will be in the midlands and the east initially. Towards morning, the heaviest rain will be across the north and northwest.”
Ms Flood added that the heaviest falls of rain “could be quite impactful” and lead to localised flooding.
“The rain will clear from mid-morning tomorrow, and Sunday won’t be too bad with some sunny spells and just some showers,” she said. “But then we do have another front coming in fairly quickly then early in the evening, so that period in the day will be short-lived.”
The UK Met Office has also issued a rain warning for Northern Ireland, from 2am on Sunday until 11am. It says the heavy rain may cause travel disruption and flooding in a few places.
