A storm is a weather-related movement of air with a wind force of at least 8 (wind speed of at least 63 km/h). Proof of the storm’s intensity must be provided by the → policyholder to be provided. This can usually be obtained from the relevant meteorological office for the region concerned.

Source reference: See the VDT publication “VDT Article Series, Part 5 | Glossary“ and the source cited there.