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Nested Grid Model
The Nested Grid Model (usually known as NGM for short) was a numerical weather prediction model run by the National Centers for Environmental Prediction, a division of the National Weather Service, in the United States. The NGM was, as its name suggested, derived from two levels of grids: a hemispheric-scale grid and a synoptic scale meteorology, synoptic-scale grid, the latter of which had a resolution of approximately 90 kilometers. Its most notable feature was that it assumed the hydrostatic equation.NCEP Nested Grid Model Overview National Weather Service Southern Region Headquarters. Retrieved 2010-05-15. The NGM debuted in 1987, directly replacing the limited-area fine mesh (LFM) model, which was immediately halted upon the NGM's debut. The NGM was also used to create model output statistics. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NGM 700 MB , a Swedish exchange for Nordic growth companies
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NGM can refer to: * NASDAQ Global Market * National Guitar Museum, USA *Neoclassical growth model * Nested Grid Model, for weather prediction * Nevada Gold Mines, a mining company * New Generation Mobile, a phone manufacturer *Nordic Growth Market Nordic Growth Market (NGM Exchange) is a regulated exchange that delivers trading, exchange technology and public company services. Established in 1984, the exchange operates in Sweden, Finland, Denmark, and Norway. Since 2008, Nordic Growth Mar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Numerical Weather Prediction
Numerical weather prediction (NWP) uses mathematical models of the atmosphere and oceans to weather forecasting, predict the weather based on current weather conditions. Though first attempted in the 1920s, it was not until the advent of computer simulation in the 1950s that numerical weather predictions produced realistic results. A number of global and regional forecast models are run in different countries worldwide, using current weather observations relayed from radiosondes, weather satellites and other observing systems as inputs. Mathematical models based on the same physical principles can be used to generate either short-term weather forecasts or longer-term climate predictions; the latter are widely applied for understanding and projecting climate change. The improvements made to regional models have allowed significant improvements in Tropical cyclone track forecasting, tropical cyclone track and air quality forecasts; however, atmospheric models perform poorly at han ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Centers For Environmental Prediction
The United States National Centers for Environmental Prediction (NCEP) delivers national and global weather, water, climate, and space weather guidance, forecasts, warnings, and analyses to government agencies and private users. The centers form part of the National Weather Service. NCEP consists of nine centers: # Aviation Weather Center provides aviation warnings and forecasts of hazardous flight conditions at all levels within domestic and international air space. # Climate Prediction Center monitors and forecasts short-term climate fluctuations and provides information on the effects climate patterns can have on the nation. # Environmental Modeling Center develops and improves numerical weather, climate, hydrological and ocean prediction through a broad program in partnership with the research community. # National Hurricane Center provides forecasts of the movement and strength of tropical weather systems and issues watches and warnings for the North Atlantic and the E ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Weather Service
The National Weather Service (NWS) is an Government agency, agency of the Federal government of the United States, United States federal government that is tasked with providing weather forecasts, warnings of hazardous weather, and other weather-related products to organizations and the public for the purposes of protection, safety, and general information. It is a part of the National Oceanic and Atmospheric Administration (NOAA) branch of the United States Department of Commerce, Department of Commerce, and is headquartered in Silver Spring, Maryland, within the Washington metropolitan area. The agency was known as the United States Weather Bureau from 1891 until it adopted its current name in 1970. The NWS performs its primary task through a collection of national and regional centers, and 122 local List of National Weather Service Weather Forecast Offices, Weather Forecast Offices (WFOs). As the NWS is an agency of the U.S. federal government, most of its products are in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Synoptic Scale Meteorology
In meteorology, the synoptic scale (also called the large scale or cyclonic scale) is a horizontal length scale of the order of or more. This corresponds to a horizontal scale typical of mid-latitude depressions (e.g. extratropical cyclones). Most high- and low-pressure areas seen on weather maps (such as surface weather analyses) are synoptic-scale systems, driven by the location of Rossby waves in their respective hemisphere. Low-pressure areas and their related frontal zones occur on the leading edge of a trough within the Rossby wave pattern, while high-pressure areas form on the back edge of the trough. Most precipitation areas occur near frontal zones. The word '' synoptic'' is derived from the Ancient Greek word (), meaning "seen together". The Navier–Stokes equations applied to atmospheric motion can be simplified by scale analysis in the synoptic scale. It can be shown that the main terms in horizontal equations are Coriolis force and pressure gradient terms ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrostatic Equation
Hydrostatics is the branch of fluid mechanics that studies fluids at hydrostatic equilibrium and "the pressure in a fluid or exerted by a fluid on an immersed body". The word "hydrostatics" is sometimes used to refer specifically to water and other liquids, but more often it includes both gases and liquids, whether compressible or incompressible. It encompasses the study of the conditions under which fluids are at rest in stable equilibrium. It is opposed to ''fluid dynamics'', the study of fluids in motion. Hydrostatics is fundamental to '' hydraulics'', the engineering of equipment for storing, transporting and using fluids. It is also relevant to geophysics and astrophysics (for example, in understanding plate tectonics and the anomalies of the Earth's gravitational field), to meteorology, to medicine (in the context of blood pressure), and many other fields. Hydrostatics offers physical explanations for many phenomena of everyday life, such as why atmospheric press ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Model Output Statistics
In weather forecasting, model output statistics (MOS) is a multiple linear regression technique in which predictands, often near-surface quantities (such as two-meter-above-ground-level air temperature, horizontal visibility, and wind direction, speed and gusts), are related statistically to one or more predictors. The predictors are typically forecasts from a numerical weather prediction (NWP) model, climatic data, and, if applicable, recent surface observations. Thus, output from NWP models can be transformed by the MOS technique into sensible weather parameters that are familiar to a layperson. Background Output directly from the NWP model's lowest layer(s) generally is not used by forecasters because the actual physical processes that occur within the Earth's boundary layer are crudely approximated in the model (i.e., physical parameterizations) along with its relatively coarse horizontal resolution. Because of this lack of fidelity and its imperfect initial state, forecasts ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mesoscale Meteorology
Mesoscale meteorology is the study of weather systems and processes at horizontal scales of approximately to several hundred kilometres. It is smaller than synoptic scale meteorology, synoptic-scale systems (1,000 km or larger) but larger than Microscale meteorology, microscale (less than 1 km). At the small end, it includes storm-scale phenomena (the size of an individual thunderstorm). Examples of mesoscale weather systems are sea breezes, squall lines, and mesoscale convective complexes. Vertical velocity often equals or exceeds horizontal velocities in mesoscale meteorological systems due to nonhydrostatic processes such as buoyant acceleration of a rising thermal or acceleration through a narrow mountain pass. Classification The History of weather forecasting, earliest networks of weather observations in the late 1800s and early 1900s could detect the movement and evolution of larger, synoptic scale, synoptic-scale systems like high pressure area, high and low-pressure area ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Global Forecast System
The Global Forecast System (GFS) is a global numerical weather prediction system containing a global computer model and variational analysis run by the United States' National Weather Service (NWS). Operation The mathematical model is run four times a day, and produces forecasts for up to 16 days in advance, but with decreased spatial resolution after 10 days. The forecast skill generally decreases with time (as with any numerical weather prediction model) and for longer term forecasts, only the larger scales retain significant accuracy. It is one of the predominant synoptic scale medium-range models in general use. Principles The GFS model has a finite volume cubed sphere (FV3) dynamical core with an approximate horizontal resolution of 28 km between grid points, which drops to 70 km between grid points for forecasts between one and two weeks. In the vertical, the model is divided into 127 layers and extends to the mesopause (roughly ~80 km). It produces forec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eta Model
Eta ( ; uppercase , lowercase ; ''ē̂ta'' or ''ita'' ) is the seventh letter of the Greek alphabet, representing the close front unrounded vowel, . Originally denoting the voiceless glottal fricative, , in most dialects of Ancient Greek, its sound value in the classical Attic dialect was a long open-mid front unrounded vowel, , which was raised to in Hellenistic Greek, a process known as iotacism or itacism. In the ancient Attic number system (Herodianic or acrophonic numbers), the number 100 was represented by "", because it was the initial of , the ancient spelling of = "one hundred". In the later system of (Classical) Greek numerals eta represents 8. Eta was derived from the Phoenician letter heth . Letters that arose from eta include the Latin H and the Cyrillic letters И and Й. History Consonant h The letter shape 'H' was originally used in most Greek dialects to represent the voiceless glottal fricative, . In this function, it was borrowed in the 8th c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
North American Mesoscale Model
The North American Mesoscale Model (NAM) is a numerical weather prediction model run by National Centers for Environmental Prediction for short-term weather forecasting. Currently, the Weather Research and Forecasting Non-hydrostatic Mesoscale Model (WRF-NMM) model system serves as the dynamical core of the NAM model. The WRF replaced the Eta model on June 13, 2006. The NAM is run four times a day (00, 06, 12, 18 UTC) out to 84 hours, with 12 km horizontal resolution and with three-hour temporal resolution, providing finer detail than other operational forecast models. Its ensemble is known as the ''Short Range Ensemble Forecast'' (SREF) and runs out 87 hours. See also * High Resolution Rapid Refresh (HRRR) * Global Forecast System * NEXRAD NEXRAD or Nexrad (Next-Generation Radar) is a network of 159 high-resolution S-band pulse-Doppler radar, Doppler weather radars operated by the National Weather Service (NWS), an agency of the National Oceanic and Atmospheric Admini ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
