Weather Definitions Ipsum
Copied Text to Buffer
Aneroid barometer: an instrument for measuring the atmospheric pressure. it registers the change in the shape of an evacuated metal cell to measure variations on the atmospheric pressure. the aneroid is a thin-walled metal capsule or cell, usually made of phosphor bronze or beryllium copper. the scales on the glass cover measure pressure in both inches and millibars. aphelion: the point on the earth's orbit that is farthest from the sun. although the position is part of a 21,000 year cycle, currently it occurs around july, when the earth is about 3 million miles farther from the sun than at perihelion. this term can be applied to any other celestial body in orbit around the sun. it is the opposite of perihelion. avhrr: acronym for advanced very high resolution radiometer. it is the main sensor on the u.s. polar orbiting satellites. confluence: a rate at which wind flow comes together along an axis oriented normal to the flow in question. the opposite of diffluence. coriolis effect: a force per unit mass that arises solely from the earth's rotation, acting as a deflecting force. it is dependent on the latitude and the speed of the moving object. in the northern hemisphere, air is deflected to the right of its path, while in the southern hemisphere, air is deflected to the left of its path. it is greatest at the poles, north and south, and almost nonexistent at the equator. cumulus mediocris: cumulus clouds characterized by moderate vertical development with upper protuberances not very marked in appearance. this cloud does not produce precipitation, but could develop into towering cumulus or cumulonimbus which do. cyclone: an area of closed pressure circulation with rotating and converging winds, the center of which is a relative pressure minimum. the circulation is counterclockwise in the northern hemisphere and clockwise in the southern hemisphere. also called a low pressure system and the term used for a tropical cyclone in the indian ocean. other phenomena with cyclonic flow may be referred to by this term, such as dust devils, tornadoes, and tropical and extratropical systems. the opposite of an anticyclone or a high pressure system. filling: used in describing the history of a low pressure system or an area of cyclonic circulation, it means an increase in the central pressure of the system. although it usually describes the action of a pressure system on a constant pressure chart, it also means a surface low is decreasing in cyclonic circulation and losing its characteristics. the opposite of deepening. frozen precipitation: precipitation that reaches the ground in a frozen state. examples include snow, snow pellets, snow grains, ice crystals, ice pellets, and hail. intermountain high: an area of high pressure that occurs during the winter between the rocky mountains and the sierra-cascade ranges. it blocks the eastward movement of pacific cyclones. also called plateau high or great basin high. meteorology/meteorologist: the science and study of the atmosphere and atmospheric phenomena. various areas of meteorology include agricultural, applied, astrometerology, aviation, dynamic, hydrometeorology, operational, and synoptic, to name a few. a scientist who studies the atmosphere and atmospheric phenomena. oxygen (o2): a colorless, tasteless, odorless gas that is the second most abundant constituent of dry air, comprising 20.946%. plow/plough wind: the spreading downdraft and strong straight-line winds preceding a thunderstorm. so named in the american midwest because of its ability to flatten tall grasses as it passes. rain forest: a forest which grows in a region of heavy annual precipitation. there are two major types, tropical and temperate. scud: low fragments of clouds, usually stratus fractus, that are unattached and below a layer of higher clouds, either nimbostratus or cumulonimbus. they are often along and behind cold fronts and gust fronts, being associated with cool moist air, such as an outflow from a thunderstorm. when observed from a distance, they are sometimes mistaken for tornadoes. sea mile: a unit of length distinguished from a nautical mile. one sea mile is equivalent to 1,000 fathoms (6,000 feet). steam fog: a type of advection fog that is produced by evaporation when cool air passes over a warm wet surface and the fog rises, giving the appearance of steam. also called sea smoke when it occurs over the ocean. storm: an individual low pressure disturbance, complete with winds, clouds, and precipitation. the name is associated with destructive or unpleasant weather. storm-scale refers to disturbances the size of individual thunderstorms. theodolite: an optical instrument used to track the motion of a pilot balloon, or pibal, by measuring the elevation and azimuth angles. watch: a forecast issued well in advance of a severe weather event to alert the public of the possibility of a particular hazard, such as tornadoes, severe thunderstorms, flash and river floods, winter storms, or heavy snows..
Generate New Ipsum
Autumn: the season of the year which occurs as the sun approaches the winter solstice, and characterized by decreasing temperatures in the mid-latitudes. customarily, this refers to the months of september, october, and november in the north hemisphere and the months of march, april, and may in the southern hemisphere. astronomically, this is the period between the autumnal equinox and the winter solstice. aviation weather center: as one of the national centers for environmental prediction, it is the national center for weather information that is used daily by the federal aviation administration, commercial airlines, and private pilots. it is entering a new phase of service, growing to accept global forecasting responsibilities. : for further information, contact the awc, located in kansas city, missouri. blowing dust: dust that is raised by the wind to heights of six feet or greater. it is reported as "bldu" in an observation and on the metar. condensation nuclei: a particle upon which condensation of water vapor occurs. it may be either in a solid or liquid state. dusk: the period of waning light from the time of sunset to dark. fusion: the change of state from a solid to a liquid at the same temperature. the heat of fusion is the number of gram calories of heat necessary to change one gram of a substance from the solid to the liquid state. it is the opposite of freezing. heat exhaustion: the effect of excessive heat, particularly when combined with high humidity, on a human being. signs of heat exhaustion include a general weakness, heavy sweating and clammy skin, dizziness and/or fainting, and muscle cramps. lifted index (li): a measure of atmospheric instability that is obtained by computing the temperature that the air near the ground would have if it were lifted to a higher level and comparing it to the actual temperature at that altitude. positive values indicate more stable air and negative values indicate instability. measured ceiling: a ceiling classification applied when the ceiling value has been determined by an instrument, such as a ceilometer or ceiling light, or by the known heights of unobscured portions of objects, other than natural landmarks, near the runway. minimum: the least value attained by a function, for example, temperature, pressure, or wind speed. the opposite of maximum. mist: a collection of microscopic water droplets suspended in the atmosphere. it does not reduce visibility as much as fog and is often confused with drizzle. mountain breeze: a katabatic wind, it is formed at night by the radiational cooling along mountainsides. as the slopes become colder than the surrounding atmosphere, the lower levels of air cool and drain to the lowest point of the terrain. it may reach several hundred feet in depth, and extreme cases, attain speeds of 50 knots or greater. it blows in the opposite direction of a valley breeze. pressure jump: a sudden increase in the observed atmospheric pressure or station pressure. prognostic chart: a chart of forecast predictions that may include pressure, fronts. precipitation, temperature, and other meteorological elements. also known as a prog. scud: low fragments of clouds, usually stratus fractus, that are unattached and below a layer of higher clouds, either nimbostratus or cumulonimbus. they are often along and behind cold fronts and gust fronts, being associated with cool moist air, such as an outflow from a thunderstorm. when observed from a distance, they are sometimes mistaken for tornadoes. sleet: also known as ice pellets, it is winter precipitation in the form of small bits or pellets of ice that rebound after striking the ground or any other hard surface. it is reported as "pe" in an observation and on the metar. snowburn: a burn of the skin, like a sunburn, but caused by the sun's rays reflected off the snow surface. zenith: the point which is elevated 90 degrees from all points on a given observer's astronomical horizon. the point on any given observer's celestial sphere that lies directly above him. the opposite of nadir..
Calorie: in meteorology, it is the amount of heat required to raise the temperature of one (1) gram of water one (1) degree celsius. it is a unit of heat energy. cold wave: a rapid fall in temperature within twenty-four hours to temperatures requiring substantially increased protection to agriculture, industry, commerce, and social activities. national weather service criteria includes the rate of temperature fall and the minimum to which it falls, depending on the region of the country and time of the in year. the weather channel uses the following criteria for a cold wave: a cold spell of two days or more with below normal temperatures in at least fifteen states, with at least five of them more than fifteen degrees below normal. constant pressure surface: a surface along which the atmospheric pressure is equal everywhere. continental shelf: the zone around the continents extending from the low-water mark seaward, typically ending in steep slope to the depths of the ocean floor. cyclogenesis: the process that creates a new low pressure system or cyclone, or intensifies a pre-existing one. it is also the first appearance of a trough. depression: in meteorology, it is another name for an area of low pressure, a low, or trough. it also applies to a stage of tropical cyclone development and is known as a tropical depression to distinguish it from other synoptic features. filling: used in describing the history of a low pressure system or an area of cyclonic circulation, it means an increase in the central pressure of the system. although it usually describes the action of a pressure system on a constant pressure chart, it also means a surface low is decreasing in cyclonic circulation and losing its characteristics. the opposite of deepening. gravitation: the mutual attraction between two masses of matter. the rotation of the earth and the atmosphere modifies this attraction to produce the field of gravity. lifted index (li): a measure of atmospheric instability that is obtained by computing the temperature that the air near the ground would have if it were lifted to a higher level and comparing it to the actual temperature at that altitude. positive values indicate more stable air and negative values indicate instability. neap tide: a tide of decreased range, which occurs about every two weeks when the moon is at one quarter or three-quarters full. nimbostratus: this cloud exhibits a combination of rain or snow, and sometimes the base of the cloud cannot be seen because of the heaviness of precipitation. they are generally associated with fall and winter conditions, but can occur during any season. snow devil: a small, rotating wind that picks up loose snow instead of dirt (like a dust devil) or water (like a waterspout). formed mechanically by the convergence of local air currents. may be called a snowspout. thunderstorm: produced by a cumulonimbus cloud, it is a microscale event of relatively short duration characterized by thunder, lightning, gusty surface winds, turbulence, hail, icing, precipitation, moderate to extreme up and downdrafts, and under the most severe conditions, tornadoes. wind: air that flows in relation to the earth's surface, generally horizontally. there are four areas of wind that are measured: direction, speed, character (gusts and squalls), and shifts. surface winds are measured by wind vanes and anemometers, while upper level winds are detected through pilot balloons, rawin, or aircraft reports. yellow snow: snow that is given golden, or yellow, appearance by the presence of pine or cypress pollen in it. : :.