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 Francis Beaufort Rear Admiral Sir Francis Beaufort, KCB, FRS, FRGS, FRAS, MRIA (; 27 May 1774 – 17 December 1857) was an Irish hydrographer and officer in the Royal Navy. Beaufort was the creator of the Beaufort Scale for indicating wind force. Francis Beaufort was descended from French Protestant Huguenots, who fled the French Wars of Religion in the sixteenth century. His parents moved to Ireland from London. His father, Daniel Augustus Beaufort, was a Protestant clergyman from Navan, County Meath, Ireland, and a member of the learned Royal Irish Academy. His mother Mary was the daughter and co-heiress of