Great Storm of 1987 from Portland Bill, Dorset to Cromer, Norfolk the return period of the respective gusts were under 10 years. Sustained winds speeds greater than 75 mph were recorded for over an hour in southern Britain. According to the Beaufort scale of wind intensities, this storm had winds of hurricane force 12 (73 mph or greater); as the term "hurricane" refers to tropical cyclones originating in the North Atlantic or North Pacific, the descriptor "great storm" has tended to be reserved for those storms in recent years reaching this velocity. Hurricanes have a very different wind profile and distribution from storms, and
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