Compared to previous summers, the 2016 season has suffered an unprecedented amount of severe weather. Heavy thunderstorms have disrupted traffic flows and caused significant delays. Some cells have extended vertically to an altitude making it impossible to fly over them. To ensure the safety of passengers, departures have had to be postponed until the weather fronts have either dissipated or moved on. This means that passengers have had to wait on board for an hour or longer before finally taking off. The FABEC air navigation service providers have addressed this problem and worked out concrete solutions.