Valentin Gebhart

1 Introduction Impact-based forecasts and warnings have recently received increasing attention (Potter et al. 2018, 2025; Taylor et al. 2018; Zhang et al. 2019; Merz et al. 2020; Schroeter et al. 2021; Golding 2022; Geiger et al. 2024).

1 Introduction Hail is a major meteorological hazard in Europe, with individual hail events capable of exceeding one billion EUR in losses (Kunz et al. 2018). Hail storms cause substantial damage to agriculture, vehicles, and buildings while occurring more frequently than tornadoes, which makes them the dominant damage driver of severe convective storms (Gunturi and Tippett 2017).

Abstract The geometric (Berry-Pancharatnam) phase originates from the intrinsic geometry of the space of quantum states and can be observed in different situations, such as a cyclic evolution of a quantum system. Here, we utilize the geometric phase to obtain a surprising insight: It is possible to create nonlocal correlations in a fixed interferometer with independent photon inputs by varying the photons' internal states.