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The fastest wind speed not related to tornadoes ever recorded was during the passage of Tropical Cyclone Olivia on 10 April 1996: an automatic weather station on Barrow Island, Australia, registered a maximum wind gust of 113.3 m/s (408 km/h; 253 mph; 220.2 kn; 372 ft/s) [6] [7] The wind gust was evaluated by the WMO Evaluation Panel, who found ...
A wind speed gradient of 4 (m/s)/km can produce refraction equal to a typical temperature lapse rate of 7.5 °C/km. [51] Higher values of wind gradient will refract sound downward toward the surface in the downwind direction, [52] eliminating the acoustic shadow on the downwind side. This will increase the audibility of sounds downwind.
At 20 °C (68 °F), the speed of sound in air, is about 343 m/s (1,125 ft/s; 1,235 km/h; 767 mph; 667 kn), or 1 km in 2.91 s or one mile in 4.69 s. It depends strongly on temperature as well as the medium through which a sound wave is propagating.
Wind speed Wave height Sea conditions Land conditions Sea conditions (photo) Associated warning flag 0 Calm < 1 knot < 1 mph < 1 km/h 0–0.2 m/s: 0 ft 0 m Sea like a mirror Smoke rises vertically 1 Light air 1–3 knots 1–3 mph 1–5 km/h 0.3–1.5 m/s 0–1 ft 0–0.3 m Ripples with appearance of scales are formed, without foam crests
The wind profile power law relationship is = where is the wind speed (in metres per second) at height (in metres), and is the known wind speed at a reference height .The exponent is an empirically derived coefficient that varies dependent upon the stability of the atmosphere.
The apparent wind is the wind experienced by an observer in motion and is the relative velocity of the wind in relation to the observer. [citation needed]The velocity of the apparent wind is the vector sum of the velocity of the headwind (which is the velocity a moving object would experience in still air) plus the velocity of the true wind.
The wind speed in cyclonic circulation grows from zero as the radius increases and is always less than the geostrophic estimate. In the anticyclonic-circulation example, there is no wind within the distance of 260 km (point R*) – this is the area of no/low winds around a pressure high.
Lake Garda in Italy is a deep, elongated lake, measuring about 350 m in depth and spanning 45 km in length. With a wind speed of 25 m/s from the SSW, the Bretschneider and Wilson formulas suggest an H s of 3.5 m and a period of roughly 7 s (assuming the storm persists for at least 4 hours). The Young and Verhagen formula, however, predicts a ...