Ireland's World Cup opening clash with Scotland could be in danger if a forecasted thunderstorm arrives in Yokohama this weekend. 

Joe Schmidt's side are due to take on the Scots at the International Stadium in Yokohama, which has already been hit by heavy rain this week.

Ireland were forced to call off a press event at their training ground on Monday due to the poor weather and the outlook for the weekend is just as bad, with an inch of rain forecast for Sunday.

Should the weather win out and the game is cancelled it will not be re-arranged and instead both sides will be awarded a draw.

Speaking to the Guardian, tournament director Alan Gilpin explained the process under which a decision to cancel the game would be taken: "A decision will be made in the main operation centre. A number of people will analyse information and we are in constant discussions with transport authorities and host cities.

"We will start the process 24 hours before a game and any decision would ultimately be taken by the executive director [Akira Shimazu] and me six to eight hours ahead of kick-off."

Meanwhile Scotland have been preparing for the testing conditions by practicing with balls covered in shampoo.