"be seen from considering the torque-rotor speed diagram. In reference to the above torque-rotor speed diagram, by reducing the rotor speed at high wind speeds, the turbine enters the stall region, thus bringing some limiting to the power output. Pitch regulation thus allows the wind turbine to actively change the angle of attack of the air on the blades. This is preferred over a stall-regulated wind turbine as it enables far greater control of the power output. Identical to the stall-regulated variable-speed wind turbine, the initial operating strategy is to operate on the formula_37 curve. However, due to constraints such"
"warning. These designations were standardized nationally in 2008, whereas ""light wind"" can refer to 0 to 12 or 0 to 15 knots and ""moderate wind"" 12 to 19 or 16 to 19 knots, depending on regional custom, definition or practice. Prior to 2008, a ""strong wind warning"" would have been referred to as a ""small craft warning"" by Environment Canada, similar to US terminology. (Canada and the USA have the Great Lakes in common.) Beaufort scale The Beaufort scale is an empirical measure that relates wind speed to observed conditions at sea or on land. Its full name is the"
"lake wind advisory is issued for winds just below this range, because unobstructed winds across the open waters of a lake are normally faster than across land. The wind speed that triggers the advisory has changed over time. Until the late 1960s, the threshold was 32 to 38 miles per hour (or 28 to 33 knots). At some point, the lower limit was reduced to 23 miles per hour (20 knots). Today, however, most places have standardized on 25 to 38 miles per hour (22 to 33 knots), encompassing the combined ranges of forces 6 and 7 on the Beaufort"
"winds in hurricanes would be 23 in the scale. Today, hurricane-force winds are sometimes described as Beaufort scale 12 through 16, very roughly related to the respective category speeds of the Saffir–Simpson hurricane scale, by which actual hurricanes are measured, where Category 1 is equivalent to Beaufort 12. However, the extended Beaufort numbers above 13 do not match the Saffir–Simpson scale. Category 1 tornadoes on the Fujita and TORRO scales also begin roughly at the end of level 12 of the Beaufort scale, but are independent scales – although the TORRO scale wind values are based on the 3/2 power"
"Beaufort scale The Beaufort scale is an empirical measure that relates wind speed to observed conditions at sea or on land. Its full name is the Beaufort wind force scale. The scale was devised in 1805 by the Irish hydrographer Francis Beaufort (later Rear Admiral Sir Francis Beaufort), a Royal Navy officer, while serving on HMS ""Woolwich"". The scale that carries Beaufort's name had a long and complex evolution from the previous work of others (including Daniel Defoe the century before) to when Beaufort was Hydrographer of the Navy in the 1830s when it was adopted officially and first used"
"scale, decoded as 32–38 mph, or a ""moderate Gale"". Beaufort, like other patrons of exploration, has had his name given to many geographical places. Among these: Beaufort created the Beaufort cipher. It is a substitution cipher similar to the Vigenère cipher. Francis Beaufort Rear Admiral Sir Francis Beaufort, KCB, FRS, FRGS, FRAS, MRIA (; 27 May 1774 – 17 December 1857) was an Irish hydrographer and officer in the Royal Navy. Beaufort was the creator of the Beaufort Scale for indicating wind force. Francis Beaufort was descended from French Protestant Huguenots, who fled the French Wars of Religion in the"
"force for coastal areas, between and . The definition is very non-standard. A common alternative definition of the maximum is . The most common way of measuring wind force is with the Beaufort scale which defines a gale as wind from to . It is an empirical measure for describing wind speed based mainly on observed sea conditions. On the original 1810 Beaufort wind force scale, there were four different ""gale"" designations whereas generally today there are two gale forces, 8 and 9, and a near gale 7: The word ""gale"" is derived from the older ""gail"", but its origin"
"issued if winds of Beaufort force 9 or frequent gusts of at least 52 knots are expected.; ""Storm Force Warnings"" are issued if Beaufort force 10 or frequent gusts of at least 61 knots are expected; ""Violent Storm Force Warnings"" are issued if Beaufort force 11 or frequent gusts of at least 69 knots are expected; ""Hurricane Force Warnings"" are issued if winds of greater than 64 knots are expected. This scale is also widely used in the Netherlands, Germany, Greece, China, Taiwan, Hong Kong, Malta and Macau, although with some differences between them. Taiwan uses the Beaufort scale with"
"predicted large-scale, cyclonic windstorms with potential for significant land-based wind impacts. This may result in names being allocated to events that are below the traditional Beaufort scale definition of a storm. A storm will be named when it is deemed able to have a ""substantial"" impact on the UK or Ireland. Met Éireann names any storm which triggers a status Orange or Red weather warning focusing on wind, though consideration was also given to rain and snow events in 2016–17. The basis for such as outlined on their weather warning service are mean wind speeds in excess of 40 mph"
"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"
"winds"" warning will be issued when squalls are expected of between 25 and 33 knots or registering force 6 to 8 on the Beaufort scale. A gale warning announces the likelihood of gale-force winds, i.e. those at speeds as of 34 knots or more or force 8 on the Beaufort scale. In order to issue these warnings, orange-coloured flashing lights are installed around the lake, which flash at a frequency of 40 times per minute for high winds or 90 times per minute for gales. It can happen that, due to the differently regulated responsibilities and assessments, a gale warning"
"at this altitude, updraughts with speeds that can exceed . Such an updraught speed corresponds to the wind speed of a small hurricane. The speed can even exceed . The maximum number in the Beaufort scale is 12 (""hurricane force"" wind) and is assigned to wind speeds of 64 knots or greater. If the Beaufort scale were extended, these updraughts would have a Beaufort number of 14 ""in the vertical direction"". The turbulence is then ""extreme"" at this altitude. Moreover, the diameters of the updraught columns vary between 2 km (air mass thunderstorm) and 10 km (supercell thunderstorm). The height"
"used in Taiwan and mainland China, which are often affected by typhoons. Internationally, WMO Manual on Marine Meteorological Services (2012 edition) defined the Beaufort Scale only up to force 12 and there was no recommendation on the use of the extended scale. Wind speed on the 1946 Beaufort scale is based on the empirical relationship: Where ""v"" is the equivalent wind speed at 10 metres above the sea surface and ""B"" is Beaufort scale number. For example, ""B"" = 9.5 is related to 24.5 m/s which is equal to the lower limit of ""10 Beaufort"". Using this formula the highest"
"than 300 km/h (160 kn; 83 m/s) were recorded, with a maximum 5-minute mean speed of 176 km/h (95 kn; 110 mph; 49 m/s), the extreme gust factor was in the order of 2.27–2.75 times the mean wind speed. The pattern and scales of the gusts suggest that a mesovortex was embedded in the already strong eyewall of the cyclone. The now second highest surface wind speed ever officially recorded is 372 km/h (231 mph; 103 m/s) at the Mount Washington (New Hampshire) Observatory: 6,288 ft (1917 m) above sea level in the US on 12 April 1934, using a"
"law relating wind velocity to Beaufort force. Wave heights in the scale are for conditions in the open ocean, not along the shore. The wind speeds in different units are not mathematically equivalent; e.g. 12–19 km/h is not equivalent to 8–12 mph, and both are not equivalent to 7–10 knots. The reason is that the Beaufort scale is not an exact nor an objective scale. It was based on visual and subjective observation of a ship and of the sea. The corresponding integral wind speeds were determined later, but the values in different units were never made equivalent. The scale"
"atmosphere based upon how far clouds move from one image to the next. Wind engineering describes the study of the effects of the wind on the built environment, including buildings, bridges and other man-made objects. Historically, the Beaufort wind force scale (created by Beaufort) provides an empirical description of wind speed based on observed sea conditions. Originally it was a 13-level scale, but during the 1940s, the scale was expanded to 17 levels. There are general terms that differentiate winds of different average speeds such as a breeze, a gale, a storm, tornado, or a hurricane. Within the Beaufort scale,"
"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"
"Wind speed Wind speed, or wind flow velocity, is a fundamental atmospheric quantity caused by air moving from high to low pressure, usually due to changes in temperature. Note that wind direction is usually almost parallel to isobars (and not perpendicular, as one might expect), due to Earth's rotation. Wind speed affects weather forecasting, aviation and maritime operations, construction projects, growth and metabolism rate of many plant species, and countless other implications. Wind speed is now commonly measured with an anemometer, but can also be classified using the older Beaufort scale, which is based on personal observation of specifically defined"
"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"
"stuck in shallows. Direct offshore winds pose the danger of being blown away from the shore in the event of equipment failure or loss of control. However offshore winds can be quite suitable in confined waters, like in a lake or estuary, or when a safety boat is assisting. The kiter must maintain a clear perception of the wind direction but also of the wind speed. The Beaufort scale is of great assistance in helping users assess the situation. A range of wind up to 33 knots covers the conditions for a safe practice for an experienced rider. A less"
"should develop gale-force wind speeds of between 34–47 kn (39–54 mph; 62–88 km/h). Severe Cyclonic Storms have storm force wind speeds of between 48–63 kn (55–72 mph; 89–117 km/h), while Very Severe Cyclonic Storms have hurricane-force winds of 64–89 kt (73–102 mph; 118–166 km/h). Extremely Severe Cyclonic Storms have hurricane-force winds of 90–119 kn (166–221 km/h, 104–137 mph). The highest classification used in the North Indian Ocean is a Super Cyclonic Storm, which have hurricane-force winds of above 120 kn (138 mph; 222 km/h). Historically, a system has been classified as a depression if it is an area where the"
"force. Gradually curving northwestward, the storm continued to gain power and, on August 18, it achieved wind speeds corresponding to Category 2 intensity on the modern-day Saffir-Simpson Hurricane Scale. This scale was devised in 1971 to categorize tropical cyclones based on their maximum sustained winds. The storm is estimated to have maintained winds of approximately 100 mph (155 km/h) for several days as it passed well to the north of the Lesser Antilles. As the hurricane turned more northerly still, approaching the United States, it strengthened to major hurricane intensity, Category 3, on August 22. At this point, it peaked"
"occurs when winds reach . The Saffir–Simpson scale and Enhanced Fujita scale were designed to help estimate wind speed from the damage caused by high winds related to tropical cyclones and tornadoes, and vice versa. Australia's Barrow Island holds the record for the strongest wind gust, reaching 408 km/h (253 mph) during tropical cyclone Olivia on 10 April 1996, surpassing the previous record of 372 km/h (231 mph) set on Mount Washington (New Hampshire) on the afternoon of 12 April 1934. The most powerful gusts of wind on Earth were created by nuclear detonations. The blast wave is similar to"
"ice crystals at atmospheric levels. Larger hailstones are capable of producing damage to property, and particularly with very large hailstones, resulting in serious injury or death due to blunt-force trauma induced by the impact of the hailstones. Hailstone size is typically correspondent to the size of an object for comparative purposes. <nowiki>*</nowiki> <br> The Beaufort scale is an empirical measure that correlates wind speed to observed conditions at sea or on land. The Enhanced Fujita scale, an updated version of the original Fujita scale that was developed by Ted Fujita with Allen Pearson, assigns a numerical rating from EF0 to"
"is uncertain. Gale A gale is a strong wind, typically used as a descriptor in nautical contexts. The U.S. National Weather Service defines a gale as 34–47 knots (, or ) of sustained surface winds. Forecasters typically issue gale warnings when winds of this strength are expected. In the United States, a gale warning is specifically a maritime warning; the land-based equivalent in National Weather Service warning products is a wind advisory. Other sources use minima as low as , and maxima as high as . Through 1986, the National Hurricane Center used the term gale to refer to winds"
"weather warning for wind. The basis for such as outlined on their weather warning service are mean wind speeds in excess of 40 mph (65 km/h) or gusts over 68 mph (110 km/h). Similarly, the Met Office name storms that have the potential to cause medium (orange) or high (red) impacts to the UK. It describes the wind strength relative to observations such as ""falling trees or tiles and other items like garden furniture being blown around."" Comparison of strongest gusts associated with each storm in the UK and Ireland. Abigail was the first storm to be officially named (jointly)"
"above 28 knots (50 km/h, 32 mph). Should a tropical depression reach wind speeds of 35 knots (65 km/h, 40 mph) then it will be classified as a moderate tropical storm and assigned a name by either the Sub Regional Center in Mauritius or Madagascar. No matter how strong a subtropical system is in this basin, it is always designated as a subtropical depression. Should the named storm intensify further and reach winds speeds of 48 knots (89 km/h, 55 mph), then it will be classified as a severe tropical storm. A severe tropical storm is designated as a tropical"
"consistent terms to refer to wind speeds, these values were not always consistent between logbooks. The researchers chose to standardise the terms into their Beaufort scale equivalents. The vocabulary used also differed between the national sources - British mariners used a relatively narrow range of terms, while sailors from the Netherlands, Spain, and France used a wider set of descriptions. Researchers found that the majority of wind force entries were accounted for by twelve or so terms, allowing the group to prepare a dictionary defining most wind force terms in use. This multi-lingual dictionary has also been published. In order"
"indicating a storm warning with northwesterly winds. By late afternoon, the storm signal flags were replaced with a vertical sequence of red, white, and red lanterns, indicating that a hurricane with winds over 74 mph (119 km/h) was coming. (The word ""hurricane"" here does not refer to a tropical cyclone, but to Force 12 winds on the Beaufort scale.) The winds on Lake Superior had already reached 50 mph (80 km/h), and an accompanying blizzard was moving toward Lake Huron. By Saturday, the storm's status had been upgraded to ""severe"". The storm was centered over eastern Lake Superior, covering the"
"scale. Winds strong enough to trigger a small craft advisory may be referred to as being advisory-force. Conversely, winds just above this intensity (39-57 miles per hour) are called gale-force, and have a separate associated warning. Occasionally an informal lesser advisory, known as ""small craft exercise caution"", is issued for wind speeds lighter than those that call for a small craft advisory. Criteria for this vary in different localities; sometimes a range of 19 to 24 miles per hour (17 to 21 knots) is observed, or in some places 17 to 23 miles per hour (15 to 19 knots) may"
"km/h) at landfall, with gusts exceeding 230 mph (370 km/h), although a reanalysis in April 2014 concluded that Camille had maximum winds of 175 mph (280 km/h) rather than the 190 mph reading used previously. Before Hurricane Katrina in 2005, Camille likely had the highest storm surge measured in the United States, at over . The storm surge quoted by the Army Corps of Engineers was based on high-water marks inside surviving buildings, of which there were but three. Prior to the collapse of the Richelieu Apartments, Ben Duckworth shone a flashlight down a stairwell and found the water within"
"barometric pressure is low compared with its surroundings. Other classifications historically used include: cyclonic storm where the winds did not exceed force 10 on the Beaufort scale and a Cyclone where the winds are either force 11 and 12 on the Beaufort scale. Between 1924 and 1988, tropical cyclones were classified into four categories: depression, deep depression, cyclonic storms and severe cyclonic storms. However, a change was made during 1988 to introduce the category ""severe cyclonic storm with core of hurricane winds"" for tropical cyclones, with wind speeds of more than . During 1999 the categories Very Severe Cyclonic Storm"
"resulting in smaller disturbances such as dust devils and whirlwinds. There are many varieties and names for storms: A strict meteorological definition of a terrestrial storm is a wind measuring 10 or higher on the Beaufort scale, meaning a wind speed of 24.5 m/s (89 km/h, 55 mph) or more; however, popular usage is not so restrictive. Storms can last anywhere from 12 to 200 hours, depending on season and geography. In North America, the east and northeast storms are noted for the most frequent repeatability and duration, especially during the cold period. Big terrestrial storms alter the oceanographic conditions"