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Nowadays, meteorologists typically express wind speed in kilometres or miles per hour or, for maritime and aviation purposes, knots, but Beaufort scale terminology is still sometimes used in weather forecasts for shipping [4] and the severe weather warnings given to the public. [5]
The National Weather Service issues a similar high wind warning (Specific Area Message Encoding code: HWW) for high winds on land. The criteria vary from place to place; however, in most cases, the warning applies to winds of 40 miles per hour (64 km/h) to 73 miles per hour (117 km/h) for at least 1 hour; or any gusts of 58 miles per hour (93 km/h) to 114 miles per hour (183 km/h) on land.
Surface weather prognostic charts for mariners indicate the positions of high and low pressure areas, as well as frontal zones, up to five days into the future. Surface wind direction and speed is also forecast on this type of chart. Wave prognostic charts show the expected sea state at some future time. [2]
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 ...
The ENIAC main control panel at the Moore School of Electrical Engineering operated by Betty Jennings and Frances Bilas. The history of numerical weather prediction began in the 1920s through the efforts of Lewis Fry Richardson, who used procedures originally developed by Vilhelm Bjerknes [1] to produce by hand a six-hour forecast for the state of the atmosphere over two points in central ...
Additionally, if a pulse Doppler weather radar is used then wind speed and direction can be determined. [44] These methods, however, leave an in-situ observational gap in the lower atmosphere (from 100 m to 6 km above ground level). To reduce this gap, in the late 1990s weather drones started to be considered for obtaining data from those ...
Recently, the wind speeds were re-examined and adjusted to a maximum official wind speed of 321 mph (516.6 km/h). [ 314 ] A DOW calculation of a subvortice of the 2013 El Reno tornado was estimated in a range of 257–336 mph (414–541 km/h) in 2024.
Warning criteria may vary depending on the NWS Weather Forecast Office. Hazardous seas watch MWS – A rough surf event—regardless of forecast wind speeds that may contribute to such an occurrence—is possible in the warned coastal area and adjacent waters, but its occurrence, location, and/or timing remains uncertain. Warning criteria may ...