Bad weather is threatening to play havoc today with the return to Ireland's Slane Castle of ageing rockers the Rolling Stones.
Heavy rain was expected to fall throughout the day but optimistic forecasters offered fans a ray of hope with a chance of sun in the evening as the band take to the stage.
Fans are being urged to come prepared for the sodden castle grounds with waterproofs and wellies order of the day. Umbrellas, however, are banned.
Mick, Keith, Ron and Charlie return to the Co Meath venue a quarter of century after they last took to the stage by the banks of the River Boyne.
"It's not going to be that good, I'm afraid," said Jean Byrne, forecaster with Met Eireann.
"There's going to be showery rain from time to time and there is a risk of heavy, even thundery, downpours.
"And there won't be a lot of brightness, the sun just might come through now and again and if it does it will be quite warm."
Gardai have warned anyone without tickets not to turn up as they will not be admitted.
Motorists travelling to Slane can use signposted free car parking spaces on the N51 Navan Road, the N51 Drogheda Road, the R163 Kells Rd and on the N2 south of Slane.
Drivers coming from the M1 are advised to leave the motorway at the Drogheda North/Slane exit while private buses should leave at the Collon exit and travel through Collon to Slane along the N2.
Other motorists have been warned of diversions around Slane from 8am until 2am on Sunday.
Dublin Bus expects to carry more than 15,000 fans to and from the gig with an express bus service operating from the city centre from 11am to 6pm.