A storm is defined as a strong wind event with wind speeds of at least 75 km/h, as this is the threshold at which storm damage typically begins to occur. In the case of storms with persistently high wind speeds, the wind pressure and the resulting stronger gusts can cause serious damage to infrastructure and buildings, such as torn-off roofs and toppled trees or electricity pylons. Falling or flying objects also often cause damage.
The storm risk is determined using the K.A.R.L.® natural hazard model. It determines the peak gusts expected for specific return periods, as these cause the greatest damage and are therefore decisive for assessing the degree of risk. The exposure of a location to storms is taken into account in the risk assessment using the digital elevation model.