Spindrift states: Force 8, defined as "Gale". Wind speed 39-46 mph, equal to 34-40 knots. Inland, twigs break off trees; progress generally impeded. At sea, moderately high waves of greater length; edges of crests begin to break into spindrift; foam is blown in well-marked streaks along the direction of the wind. Relatedly, "spindrift" can also be used to describe fine sand or snow that is blown off by the wind. "Spindrift" is a southern English word, "Spoondrift" a northern or Scottish word. The Scottish word "spoondrift" can be used to describe fine snow that is blown off the hills by the
Wind in the source air mass. In California, downslope winds are funneled through mountain passes, which intensify their effect, and examples include the Santa Ana and sundowner winds. Wind speeds during downslope wind effect can exceed . As described earlier, prevailing and local winds are not spread evenly across the earth, which means that wind speeds also differ by region. In addition, the wind speed also increases with the altitude. Nowadays, a yardstick used to determine the best locations for wind energy development is referred to as wind power density (WPD). It is a calculation relating to the effective force of