Beaufort scale

Admiral Sir Francis Beaufort, Royal Navy, (1774-1857) did not invent the wind scale that bears his name, but he significantly refined the scale and worked vigorously to expand its usage. In his position as Hydrographer, he was able to issue orders to commanding officers and masters of naval vessels, including the master of the HMS Beagle on the voyage of Charles Darwin, to utilize the scale in logging weather conditions. The scale runs from 0 for calm (flat sea); through 3 for gentle breeze (large wavelets, crests begin to break); and 7 for high wind/moderate gale (sea heaps up, moderate amounts of airborne spray); to 12 for hurricane (huge waves, sea is completely white). The initial version of his wind scale did not include wind speeds. Rather, it related to the impact of the wind on the sails of a man of war. As ships replaced their sails with mechanical engines, the scale evolved to the one used today. Hurricane force winds were all grouped together as any wind with a speed of 64 knots or greater. In recent years, the Saffir-Simpson hurricane scale has been appended to the Beaufort scale, which now runs up to 16 for wind speeds of 136 knots or greater.  The beauty of the Beaufort scale, and what has made it so useful for all these years, is that it allows one to obtain a reasonable estimate of wind speed merely by observing the surroundings – no technology needed. While the scale was first intended for use at sea, it has been adapted for mariners to use when at home, with shoreside examples being included. For example, a fresh breeze (5 on the scale) is explained as ‘branches of a moderate size move, small trees begin to sway’ in addition to ‘moderate waves of some length, many white horses’.