Beaufort scale the extension to 17 noted above. China also switched to this extended version without prior notice on the morning of 15 May 2006, and the extended scale was immediately put to use for Typhoon Chanchu. Hong Kong and Macau retain force 12 as the maximum. In the United States, winds of force 6 or 7 result in the issuance of a small craft advisory, with force 8 or 9 winds bringing about a gale warning, force 10 or 11 a storm warning ("a tropical storm warning" being issued instead of the latter two if the winds relate to a tropical
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