Maximum sustained wind 50% of the geostrophic wind speed aloft; while over open water or ice, the reduction is between 10% and 30%. In most basins, maximum sustained winds are used to define their category. In the Atlantic and northeast Pacific oceans, the Saffir–Simpson scale is used. This scale can be used to determine possible storm surge and damage impact on land. In most basins, the category of the tropical cyclone (for example, tropical depression, tropical storm, hurricane/typhoon, super typhoon, depression, deep depression, intense tropical cyclone) is determined from the cyclone's maximum sustained wind. Only in Australia is this quantity not used to
Cyclone Kyrill Aberdaron on the Lleyn peninsula, 122 km/h (76 mph) at Mumbles near Swansea and winds of 101 km/h (63 mph) at St Athan in the Vale of Glamorgan. The German Meteorological Service had advised people to stay indoors and avoid unnecessary trips on 18 January, and wind strengths of up to 12 on the Beaufort scale were seen across the Netherlands and Germany as the storm made landfall. The storm moved across the German states of Lower Saxony, Bremen, Hamburg, Schleswig-Holstein and North Rhine-Westphalia first, then spread across the whole country in the evening hours of 18 January. Wind gusts