- Possible impacts: Lightning strikes. Breaking off of branches, toppling of individual trees. Landslides on steep slopes, sudden flash floods or debris flows in streams, flooding. Hail damage. - Recommendations for action: When planning outdoor activities, take into account any available protections and alternative routes. Avoid bodies of water and areas at risk of lightning strikes, such as mountain ridges, trees, pylons or towers as well as open terrain (e.g. clearings, football pitches). Secure outdoor objects and retract any awnings. - Thunderstorm type: moving thunderstorms - Peak phase of the event: Thu 17 - Thu 23