Tribune de Genève.
Swiss Meteo is predicting heavy storms this evening. A mass of heavy unstable air is poised to unleash heavy rain, winds, and possibly hail. Storms are predicted to cover much of the Swiss plateau from Geneva through to Lake Constance. The warning is level 3, which is described as considerable danger. and covers the period until 3AM on Friday.
Recommendations to prepare for the storm are to be make sure things that could get caught by the wind are properly secured or put away. In addition, protect areas that could be susceptible to surface flooding. And to avoid standing under trees during the storm or using electrical devices connected to a power supply.
Garaging cars where possible is a good idea as hail stones can sometimes dent car roofs and bonnets.