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Colour State
Colour states is a system used for quickly showing meteorological conditions. Meteorological colour states are determined by the relevant worst condition from the visibility and significant cloud height. In the US and parts of Europe the lowest significant cloud layer is five or more oktas; in the United Kingdom, Belgium, France and the Netherlands it is three oktas or more. If visibility or cloud height measurements fall on a boundary (e.g. 5000 m visibility or 1500 ft cloud height) the colour state assumes the higher value in this case WHT. If an airfield runway is unusable for reasons other than clouds or low visibility (e.g. ice or other obstructions) then the word BLACK is written in full and placed immediately before the actual colour state (e.g. BLACKWHT). The colour state may be appended to a METAR METAR is a format for reporting weather information. A METAR weather report is predominantly used by aircraft pilots, and by meteorologists, who use aggregated ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meteorological
Meteorology is the scientific study of the Earth's atmosphere and short-term atmospheric phenomena (i.e. weather), with a focus on weather forecasting. It has applications in the military, aviation, energy production, transport, agriculture, construction, weather warnings and disaster management. Along with climatology, atmospheric physics and atmospheric chemistry, meteorology forms the broader field of the atmospheric sciences. The interactions between Earth's atmosphere and its oceans (notably El Niño and La Niña) are studied in the interdisciplinary field of hydrometeorology. Other interdisciplinary areas include biometeorology, space weather and planetary meteorology. Marine weather forecasting relates meteorology to maritime and coastal safety, based on atmospheric interactions with large bodies of water. Meteorologists study meteorological phenomena driven by solar radiation, Earth's rotation, ocean currents and other factors. These include everyday wea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Visibility
In meteorology, visibility is the measure of the distance at which an object or light can be clearly discerned. It depends on the Transparency and translucency, transparency of the surrounding air and as such, it is unchanging no matter the ambient light level or time of day. It is reported within surface weather observations and METAR code either in Metre, meters or statute miles, depending upon the country. Visibility affects all forms of traffic: road traffic, roads, railways, sailing and aviation. The geometric range of vision is limited by the curvature of the Earth and depends on the eye level and the height of the object being viewed. In geodesy, the atmospheric refraction must be taken into account when calculating geodetic visibility. Meteorological visibility Definition ICAO Annex 3 ''Meteorological Service for International Air Navigation'' contains the following definitions and note: :a) the greatest distance at which a black object of suitable dimensions, situa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cloud Base
A cloud base (or the base of the cloud) is the lowest altitude of the visible portion of a cloud. It is traditionally expressed either in metres or feet above mean sea level or above a planetary surface, or as the pressure level corresponding to this altitude in hectopascals (hPa, equivalent to the millibar). Measurement The height of the cloud base can be measured using a ceilometer. This device reflects a beam of light off the cloud base and then calculates its distance using either triangulation or travel time. Alternatively, the cloud base can be estimated from surface measurements of air temperature and humidity by calculating the lifted condensation level. One method for doing this, used by the U.S. Federal Aviation Administration and often named after Tom Bradbury, is as follows: #Find the difference between the surface temperature and the dew point. This value is known as the "spread". #Divide the spread by 4.4 (if temperatures are in °F) or 2.5 (if temperature ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Okta
In meteorology, an okta is a scale of measurement used to describe the amount of cloud cover at any given location such as a weather station. Sky conditions are estimated in terms of how many eighths of the sky are covered in cloud, ranging from 0 oktas (completely clear sky) through to 8 oktas (completely overcast). In addition, in the SYNOP code there is an extra cloud cover indicator '9' indicating that the sky is totally obscured (i.e. hidden from view), usually due to dense fog or heavy snow. When used in weather charts, okta measurements are shown by means of graphic symbols (rather than numerals) contained within weather circles, to which are attached further symbols indicating other measured data such as wind speed and wind direction. Although relatively straightforward to measure (visually, for instance, by using a mirror), oktas only estimate cloud cover in terms of the area of the sky covered by clouds. They do not account for cloud type or thickness, and this lim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
METAR
METAR is a format for reporting weather information. A METAR weather report is predominantly used by aircraft pilots, and by meteorologists, who use aggregated METAR information to assist in weather forecasting. Raw METAR is highly standardized through the International Civil Aviation Organization (ICAO), which enables it to be understood throughout most of the world. Report names In its publication the '' Aeronautical Information Manual'' (''AIM''), the United States Federal Aviation Administration (FAA) describes the report as ''aviation routine weather report'', while the international authority for the code form, the World Meteorological Organization (WMO), describes it as the ''aerodrome routine meteorological report.'' The National Oceanic and Atmospheric Administration (part of the United States Department of Commerce) and the United Kingdom's Met Office both employ the definition used by the FAA. METAR is also known as ''Meteorological Terminal Aviation Routine Weathe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Color Code
A color code is a system for encoding and representing non-color information with colors to facilitate communication. This information tends to be categorical (representing unordered/qualitative categories) though may also be sequential (representing an ordered/quantitative variable). History The earliest examples of color codes in use are for long-distance communication by use of flags, as in semaphore communication. The United Kingdom adopted a color code scheme for such communication wherein red signified danger and white signified safety, with other colors having similar assignments of meaning. As chemistry and other technologies advanced, it became expedient to use coloration as a signal for telling apart things that would otherwise be confusingly similar, such as wiring in electrical and electronic devices, and pharmaceutical pills. Encoded Variable A color code encodes a variable, which may have different representations, where the color code type should match th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
