Wind gust World Meteorological Organization. Any significant variation at this mean wind during the ten minutes preceding the observation are noted as gusts in messages such as METAR. It is generally reported in METAR when the peak wind speed reaches at least 16 knots and the variation in wind speed between the peaks and average wind is at least 9 to 10 knots. In marine meteorology, the top speed of a burst is expressed in meters per second (m/s) or in knots, while the Beaufort scale is used for reporting the mean speed. When the maximum speed exceeds the average speed by
Apparent wind of the true wind" minus the "velocity of the object". In sailing, "apparent wind" is the speed and direction of wind indicated by a wind instrument (anemometer) on a "moving" craft (on water, land or ice) in undisturbed air. It is composed of the "combined" speeds and directions of the craft and wind observed by a "stationary" wind instrument—the "true wind". A true wind coming from the bow increases the apparent wind induced by the speed of the craft, coming from the stern it decreases apparent wind, and coming from the side the apparent wind angle and speed change according