METEO FRANCE, the weather bureau, provided extreme one second averaged gust speeds for recent years at Caen-Carpiquet and St Gatien des Bois.
A wind averaged over a ten minute at a height of ten meters above ground will occur on average once every 50 year time span. The accepted value for buildings in this region is 100 Km/h at 10m height corresponds to winds of about 200Km/h at the peak of the Cross. The influence of the hilly terrain on wind speed where the Cross is to be raised (see map below) has been evaluated at +10% at the base and +3% at an altitude of 100m.
The future needs of the project require further investigation of the winds at higher altitudes particularly for unusual conditions during extreme storms or when a jet stream forms at low altitude.