Scale of wind forces and velocities, ranging from force 0 (calm-one knot or less) to force 12 (hurricane-above 73 knots) or 17 (hurricane-above 126 knots).

【气】蒲福风级(其分级从零级(无风-风速每小时一英哩以下)到12级(飓风-风速每小时73英哩以上)或到17级(飓风-风速每小时126英哩以上)两种)。