ASCE/SEI A S C E S TA N D A R D 7–10 Minimum Design Loads for Buildings. 550 C27.4.3 Open Buildings with Monoslope, Pitched, or Troughed Free Roofs. Guidelines include the NESC, ASCE Manual 74, and ANSI/EIA/TIA-222.

An anemometer is commonly used to measure wind speed. Wind speed, or wind, is a fundamental quantity caused by air moving from to, usually due to changes in temperature. Note that wind direction is usually almost parallel to (and not perpendicular, as one might expect), due to. Wind speed affects, and operations, projects, growth and rate of many plant species, and countless other implications. Speed is now commonly measured with an, but can also be classified using the older, which is based on personal observation of specifically defined wind effects. Urok v 9 klasse pushkin besiktas. Contents • • • • • • • Factors affecting wind speed [ ] Wind speed is affected by a number of factors and situations, operating on varying scales (from micro to macro scales). These include the, and, and local weather conditions.

There are also links to be found between wind speed and, notably with the pressure gradient and terrain conditions. Pressure gradient is a term to describe the difference in air pressure between two points in the atmosphere or on the surface of the Earth. It is vital to wind speed, because the greater the difference in pressure, the faster the wind flows (from the high to low pressure) to balance out the variation. The pressure gradient, when combined with the and, also influences. Rossby waves are strong winds in the upper. These operate on a global scale and move from West to East (hence being known as ). The Rossby waves are themselves a different wind speed from what we experience in the lower.

Local weather conditions play a key role in influencing wind speed, as the formation of, and as freak weather conditions can drastically affect the flow velocity of the wind. Highest speed [ ]. The original anemometer that measured The Big Wind in 1934 at Mount Washington Observatory The fastest wind speed not related to ever recorded was during the passage of Tropical on 10 April 1996: an on,, registered a maximum wind gust of 408 km/h (220 kn; 253 mph; 113 m/s). The wind gust was evaluated by the WMO Evaluation Panel who found that the anemometer was mechanically sound and the gust was within statistical probability and ratified the measurement in 2010.

The anemometer was mounted 10 m above ground level (and thus 64 m above sea level). During the cyclone, several extreme gusts of greater 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 was embedded in the already strong of the cyclone.

Currently, the second-highest surface wind speed ever officially recorded is 372 km/h (231 mph; 103 m/s) at the Observatory: 6,288 ft (1917 m) above sea level in the US on 12 April 1934, using a heated anemometer. The anemometer, specifically designed for use on Mount Washington was later tested by the US and confirmed to be accurate. Wind speeds within certain atmospheric phenomena (such as ) may greatly exceed these values but have never been accurately measured. Directly measuring these tornadic winds is rarely done as the violent wind would destroy the instruments.