SWISS has cancelled 27 flights to and from Zurich due to severe thunderstorms over Switzerland. Around 3,100 passengers are affected and several departures are delayed by up to three hours. The airline is warning of further cancellations throughout the day.

Heavy thunderstorm cells over Switzerland and the Zurich area caused extensive disruption to air traffic at Zurich Airport on Friday.

SWISS says 27 flights have been cancelled so far. In addition, some departures have been delayed by up to three hours. Depending on how the weather develops, more flights may have to be cancelled.

Ground work is stopped in the event of a lightning strike

The problems are not only due to the possibilities of taking off and landing. Recurrent lightning strikes near the airport mean that work on the apron has to be temporarily suspended for safety reasons.

During these so-called handling stops, personnel must leave the area and keep a distance from aircraft and metal equipment. This means that aircraft cannot be loaded or unloaded, refueled or prepared for the next departure.

According to SWISS, even shorter stops can create delays that then propagate through the traffic program for the rest of the day.

At the same time, thunderstorms can limit the airport's capacity for takeoffs and landings.

Additional flight cancellations expected

SWISS says staff are working to stabilize traffic and ensure connections where possible, but the company expects continued impacts as long as the severe weather persists.

A total of around 3,100 SWISS passengers have had their flights cancelled so far, and the airline estimates that number could increase during the day.

According to the press release.