It has been 'just too dangerous' to fly in evening heatwave, says Balloon Fiesta director

The director of the Bristol International Balloon Fiesta has explained why the evening mass ascents have had to be called off on the first two days of this year's festival.

He explained the rare weather conditions that have kept the balloons tethered in the evenings so far.

Thursday, Friday and Saturday's mass ascents were called off at around 6pm, with the ground temperature on the balloon field still up around 31 degrees, and barely a breath of wind being felt by the thousands who have come to the fiesta. But it's the conditions up in the air that is the issue for balloon pilots, Mr Bailey said.

The fiesta director said that with such calm conditions around the very hot ground, dangerous thermals are created as the hot air rises from the ground.

"It is a real shame, but these thermals are not ideal at all for ballooning," said Mr Bailey.

"Thermals are what a glider pilot will use to get height without any power, and at the moment they are so very strong. There was a case this week of a glider pilot being taken up to 9,000ft by a thermal and a pilot has got the ability to steer. If a balloon pilot gets caught in one, we're just in a wicker basket with a load of hot air above us, there will be not much we could do to be able to control the balloon.

"It has the potential to be just too dangerous, so unfortunately we just can't go up when the conditions are like this," he added.

Mr Bailey said the wind conditions this year meant it was unlikely any of the ascents will take balloons over Bristol, "I don’t think we’re going to get across Bristol this fiesta, but it’s nice for the west side of Bristol to get to see the balloons".

With changeable weather and a potential break in the heatwave being forecast today (Sunday 14 August), it is impossible to say at this stage whether tonight's final Sunday evening ascent will take place.