UK Heatwave Turns to Thunderstorms, Causing Widespread Flight Delays at Heathrow and Gatwick

Flights at London's Heathrow and Gatwick airports have been delayed for up to 11 hours as the heatwave turns to thunderstorms. More than 800 flights have been delayed in and out of the two travel hubs so far on Saturday and dozens cancelled, many due to the stormy weather. The UK's air traffic control service said delays were expected to continue for the rest of the day. Some passengers have taken to social media to express their frustration, with one saying her daughter was stuck on an Easyjet plane at Gatwick for four hours before it was cancelled. Gatwick told BBC News that temporary air traffic control restrictions had been put in place, while Easyjet apologised for the disruption. More than 400 flights arriving at or departing from Heathrow have been delayed so far on Saturday, according to tracker FlightAware, and another 400 in and out of Gatwick. Delays to affected flights vary, but Heathrow's live arrival board shows a British Airways flight from Santiago, Chile that was due to land at 10:00 BST but is now not expected to arrive until 21:00 this evening. Europe-wide aviation agency Eurocontrol mapping shows the most severe air traffic control delays in airspace between south-east England and north-western Europe, where the storm clouds are currently located. However, other UK airports remain largely unaffected. NATS, the UK's air traffic control service, said "weather disruption was expected to continue through the rest of the day" after "forecasted severe weather across the south east of England". The thunderstorms developed overnight - bringing rain and lightning to parts of the UK - following a record-breaking heatwave, with the hottest ever June high of 37.3C recorded in Suffolk on Friday. An amber warning for extreme heat is in place until Sunday morning for parts of eastern and south-east England - while the thunderstorm to the south of the UK is forecast to worsen throughout Saturday afternoon. Eurocontrol said a "broad area of hot, unstable air" stretching from northern Spain to southern Sweden was likely to see further storm-cloud development overnight, adding that there was "a large degree of uncertainty" over when and where they would develop. Flights are having to avoid the area with turbulent conditions, having a knock-on effect on schedules.