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
Francis Beaufort tomb may still be seen. His home in London, No. 51 Manchester Street, Westminster, is marked by an historic blue plaque noting his residency and achievements. During these early years of command, Beaufort developed the first versions of his Wind Force Scale and Weather Notation coding, which he was to use in his journals for the remainder of his life. From the circle representing a weather station, a staff (rather like the stem of a note in musical notation) extends, with one or more half or whole barbs. For example, a stave with 3½ barbs represents Beaufort seven on the