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
Hurricane Severity Index the index uses a 50-point scale, with half of the total based on wind intensity, and half based on the wind fields. Wind radii data from every named storm since 1988 was studied. From these data, average wind radii ranges of four wind fields (39, 58, 74, and 100 mph) were calculated. Once the typical ranges were established, each wind field range was divided into sections. Since hurricane-force winds are much more damaging than tropical storm-force winds, the size scale is weighted more toward the 74 and 100 mph wind fields. With the HSI, a tropical storm can receive no