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
Wind wave this point. This relation shows the wind flow transferring its kinetic energy to the water surface at their interface. Assumptions: Generally these wave formation mechanisms occur together on the water surface and eventually produce fully developed waves. For example, if we assume a flat sea surface (Beaufort state 0), and a sudden wind flow blows steadily across the sea surface, the physical wave generation process follows the sequence: Three different types of wind waves develop over time: Ripples appear on smooth water when the wind blows, but will die quickly if the wind stops. The restoring force that allows them