Paris flood warning issued as huge downpour threatens to spoil Olympics opening ceremony

The opening ceremony of the Olympic Games in Paris is set to be hit by a huge downpour just as the festivities are about to begin, with a flood warning issued.

The games officially open in France on Friday evening, with athletes set to be welcomed by fans lining the River Seine. The ceremony is set to begin at 1:30 p.m. ET, when heavy showers are due to arrive in the French capital.

Showers have peppered Paris throughout the day before sunny spells emerged in recent hours. However, the festivities are about to begin, forecasts a significant band of rain to hang over the city in the hours ahead.

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France's meteorological office has responded to the forecast by issuing a flood warning. Up to 1.18 inches of rainfall are expected to fall before midnight local time, the equivalent of 15 days' rainfall.

Meteorologist Patrick Marliere said it is "going to be a disaster for these few hours" and added: "I’ve been running models for two hours, going full circle, comparing all weather models, but unfortunately everything is confirming this trend for the start and the end of this evening. We won’t be able to avoid it."

Paris' opening ceremony is the first not to be held in a stadium. Instead, more than 300,000 spectators will line the banks of the River Seine as boats carrying athletes sail past.

Despite the prospect of bad weather, organizers are confident the event will not be adversely affected. Arnaud Daniel, who is responsible for a fleet of 22 boats being used in the ceremony, told Euronews: “The parade and the ceremony are going to go very, very well.

"There's nothing to worry about. If the flow rate of the river goes up by a tiny bit, that's no problem, we'll just adapt the speed. We'll go from 9kmph to 10kmph, for example.

"It's going to be grandiose. It's going to be the equivalent of the Superbowl, it's insane. I invite everyone to watch the show. It's going to be a once-in-a-lifetime experience."

The opening ceremony has already presented numerous logistical challenges. The attendance capacity for the event was scaled back dramatically due to security concerns, with intelligence and defense services on alert amid a heightened risk of a terrorist attack.

Around 45,000 police officers will be in attendance, plus 10,000 soldiers and more than 20,000 security guards. Nearby airports will be closed during the ceremony and Paris' airspace will be locked down.

"Without any doubt, it is much more difficult to secure half of Paris than to secure a stadium, where you have 80,000 people and you can frisk them and send them through turnstiles," Frederic Pechenard, an ex-director general of the French police told AFP.