The 6pm briefing on Saturday 17 2016, 30 hours before the 48 Coupe Aéronautique Gordon Bennett pilots launch, was dominated by a weather briefing promising what can only be described as 'mixed' conditions across the Alps and south into the Mediterranean...

This is where it gets serious.

“Can you stop the background noise?” a voice called from the audience.

“Yes we can stop the generator,” replied one of the organisers.

“And the music – switch it off.”

From now until the race ends on Friday the game is on – and what a game it is. Forty-eight pilots from 12 nations assembled in a small gas-balloon airfield in industrial northern Germany, getting ready to blow up a balloon that hasn’t changed much since 1800, and cast themselves off into the wind in a lightweight open basket.

For the uninitiated, it looks like setting sail on the sea in a pea-green boat; for the pilots, it is an adventure of a lifetime, one of the world’s true great challenges.

Saturday’s briefing started at 6pm and went on for two hours. It was in the large marquee in the launch field, each pilot team granted a table replete with numerous bits of paperwork, the odd sponsor freebie (20 beers in a box went down well for most) and a plate of cold meats.

The pilots were here to hear the news, from organisers and the weather gurus. Each pilot is a weather guru themselves, and they all have access to professional meteorologists on their teams, so this is as serious a bunch of weather-experts as you will meet anywhere in the world.

The official weatherman, Michael Noll, took the microphone and started to talk, leading everyone through a collection of PowerPoint slides.

A low pressure over south-east Germany was to bring torrential rain there, he said. “Very intense precipitation … Warnings for flooding.”

But that low pressure was due to move east he said, and we’re at the very edge of it, so it should be ok. And anyway, it’s disappearing Monday morning.

But there are also storms in south-west France, and storms in the southern Alps, although those are due to weaken too.

Sunday, launch day, will see gusty wind in the launch field. “That will be our biggest problem,” he explained. “The models say up to 17 knots (35km/h), but that is exaggerated, expect 12-14 knots more realistically.” His optimism did not seem to be widely shared.

Monday, pilots should be on their way south he said, towards the Alps, which will be shrouded in low, orographic cloud. He spoke in terms of millibars and flight levels, which to non-pilots means little, but everyone got it and the message was not great. “Fog in the Alps,” as one pilot put it later.

Further west, things looked better, but only for a little bit. The dreaded Mistral wind would be blowing hard in southern France. This strong north wind can blow tiles off a roof, which isn’t great ballooning weather. Or rather, not great balloon-landing weather.

“It is not a good idea to land in southern France or parts of the Rhone Valley,” Noll said. “It will be too windy for a safe landing.”

Just to be sure he added: “Expect intense winds south of Avignon down to Marseille. Gusts of 40 knots (80km/h). You can not land here on Monday evening or Tuesday.”

After the south of France, the Mediterranean. Wide blue sea. “Go high and you can ride the wind to east of Sicily,” was the message. “It will be faster wind at 5,000m, slower at 3,000m.” Faster at 5,000m? For 20 hours across the Mediterranean? This was looking distinctly rough.

What day is it now? Tuesday? Wednesday? We’re somewhere over the Mediterranean anyway, at 5,000m, and have left the Mistral far behind. We’re riding a magic carpet at 80km/h along a corridor of blue sky, heading for the magic Mediterranean islands of Sardinia, Sicily, on into Greece. But wait, what’s that on the horizon?

“Wednesday, there will be thunderstorms over the mainland Italy. Clear west of Italy.”

A pilot called a question: “What do the red marks mean?” We looked closer – the Powerpoint slide showed 80% of Italy was covered in red – crosses? – symbols.

“They are thunderstorms,” came the reply.

Thunderstorms and balloons mix like sparks and petrol – they don’t. “If you stay ahead of the thunderstorm you will be ok, otherwise you will be drawn towards it,” was the advice.

Pilots know this; many in the audience know the consequences of being caught in a thunderstorm. “I went from 500m to 6,000m with no control and I was in shirt sleeves,” one pilot said afterwards. “There was six inches of snow in the basket, hailstones like tennis balls.” He knows how lucky he was.

There was a pause, questions from the floor. The summary was thus:

- Gusty on launch

- OK until you reach the Alps, which will be covered in cloud

- Head west for clearer air, but beware the Mistral

- Make a choice: land before the Mistral or fly out over the Mediterranean for the islands

- Fly the sea, and watch for storms over mainland Italy

- Aim for Crete, the long thin island somewhere east of Italy

The final words: “Don’t be afraid of the water, the weather will be fine for you.”

“Boris was a weather prophet,” said the writer Henry Miller in his 1934 classic of American literature Tropic of Cancer, “the weather will not change.”

The met briefing finished. There were questions, but the message was clear: go high and fast to get to clear air and Greece, or finish your flight early before you hit the Mistral.

Did that sound like all or nothing? No aviator wants to hear that, certainly not one in a balloon. Non-powered air sports are games of finesse, strategy, consideration, planning, review, meticulous understanding and appreciation of the weather; skill. Gambling can not – must not – come into it.

Later there was much talk, much discussion. Each team has their own weather prophet and there was a lot to discuss.

“That’s what you call a mixed forecast,” said John Rose (GBR-2) drily. “It could end in fog in the Alps, thunderstorms in Italy, or shredding your knickers in the Mistral in the Rhone Valley.” He paused a beat. “Very promising.”

Next briefing: 10am Sunday 18 September 2016

Main photo: Les Deux Benoits (FRA 03) ... Benoit Pellard, right, lets his face do the talking while his co-pilot Benoit Peterie, centre, appears more resigned. Photo: FAI / Marcus King

Report: FAI / Ed Ewing