Wind is the directed movement of air. Wind is created as a result of differences in air pressure between air masses of varying temperature. The air moves from the higher air pressure (high-pressure area) to the lower air pressure (low-pressure area) until the air pressure is balanced out. In Switzerland, westerly winds, called Bise (cold, north-easterly) and Foehn (southerly) are the most common types of wind occurring across widespread areas.
The transition altitude between ‘low and medium altitudes’ and ‘higher altitudes’ is 1000 m above sea level for the Jura and the low-lying areas of the northern side of the Alps, and 1600 m above sea level for the Alps themselves as well as their southern side.
Wind warnings are issued for levels 2 – 5.
Objects that are unsecured or inadequately secured may fall over. Smaller branches may break off.
Branches may break off and trees may be toppled. Individual roofs may be damaged. Lightly secured, large objects such as tents and scaffolding may be blown over. Road, rail, water and air travel may be disrupted. There is an increased risk of road accidents due to strong crosswinds.
Branches may break off and trees may be toppled. Individual roofs may be damaged. Lightly secured, large objects such as tents and scaffolding may be blown over. Road, rail, water and air travel may be disrupted. There is an increased risk of road accidents due to strong crosswinds.
Trees, entire groups of trees or sections of forest as well as electricity pylons/poles may be blown over. Buildings could be seriously damaged. Road, rail, water and air travel may be disrupted or come to a complete standstill. Large, empty vehicles may tip over. Large, firmly secured objects such as tents or scaffolding as well as freestanding objects such as garden furniture may also be toppled or blown away by the wind. High waves may break over the banks of lakes. The power supply and telephone communications network may suffer outages over large areas and for long periods of time.