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
RRS Discovery over the Christmas period the ship was blocked in by pack ice. A Norwegian whaler was met on December 29, which gifted the "Discovery" a further 50 tons of coal. On December 31 the ship was struck by a violent storm with winds of up to 70 mph (Force 11 on the Beaufort Scale). The ship was driven against the ice, while larger bergs were blown onto the ship by the wind. For eight hours the "Discovery" was repeatedly slammed into and onto thick ice and battered by bergs but MacKenzie was able to slowly work the ship offshore by