Weather Vanes As Art

Forecasting ... For example, including information about weather conditions might improve the ability of a model to predict umbrella sales...

Model Output Statistics ... The technique pioneered in the 1960s and early 1970s is used to post-process output from numerical weather forecast models... Generally speaking, numerical weather forecast models do an excellent job of forecasting upper air patterns but are too crude to account for local variations in surface weather... Pure statistical models, on the other hand, are excellent at forecasting idiosyncrasies in local weather but are usually worthless beyond about six hours...

Parametrization (climate) ... Clouds Weather and climate model gridboxes have sides of between 5 kilometres (3.1 mi) and 300 kilometres (190 mi)...

Space Weather ... Prior to that time, activities now known as space weather were considered to be part of physics or aeronomy or space exploration... This was described in 1600 in De Magnete but was not understood to be caused by space weather until the 19th century... Severe radar jamming during a large solar event in 1942 led to the discovery of solar radio bursts (radio waves which cover a broad frequency range created by a solar flare), another aspect of space weather...

Surface Weather Analysis ... The first weather maps in the 19th century were drawn well after the fact to help devise a theory on storm systems... After the advent of the telegraph, simultaneous surface weather observations became possible for the first time, and beginning in the late 1840s, the Smithsonian Institution became the first organization to draw real-time surface analyses... Surface weather analyses have special symbols that show frontal systems, cloud cover, precipitation, or other important information...

Weather ... Weather systems in the mid-latitudes, such as extratropical cyclones, are caused by instabilities of the jet stream flow... Weather forecasting is the application of science and technology to predict the state of the atmosphere for a future time and a given location... Human attempts to control the weather have occurred throughout human history, and there is evidence that human activity such as agriculture and industry has inadvertently modified weather patterns...

Weathering ... Two important classifications of weathering processes exist – physical and chemical weathering. Mechanical or physical weathering involves the breakdown of rocks and soils through direct contact with atmospheric conditions, such as heat, water, ice and pressure...

Weather Forecasting ... Once an all-human endeavor based mainly upon changes in barometric pressure, current weather conditions, and sky condition, weather forecasting now relies on computer-based models that take many atmospheric factors into account... Chinese weather prediction lore extends at least as far back as 300 BC, which was also around the same time ancient Indian astronomers developed weather-prediction methods... In 904 AD, Ibn Wahshiyya's Nabatean Agriculture discussed the weather forecasting of atmospheric changes and signs from the planetary astral alterations; signs of rain based on observation of the lunar phases; and weather forecasts based on the movement of winds...

Frost Weathering ... Not all volumetric expansion is caused by the pressure of the freezing water; it can be caused by stresses in water that remains unfrozen. When ice growth induces stresses in the pore water that breaks the rock, the result is called hydrofracture...

History Of Numerical Weather Prediction ... Even with the increasing power of supercomputers, the forecast skill of numerical weather models only extends to about two weeks into the future, since the density and quality of observations—together with the chaotic nature of the partial differential equations used to calculate the forecast—introduce errors which double every five days... The use of model ensemble forecasts since the 1990s helps to define the forecast uncertainty and extend weather forecasting farther into the future than otherwise possible... Background Until the end of the 19th century, weather prediction was entirely subjective and based on empirical rules, with only limited understanding of the physical mechanisms behind weather processes...

Numerical Weather Prediction ... 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... Manipulating the vast datasets and performing the complex calculations necessary to modern numerical weather prediction requires some of the most powerful supercomputers in the world... Even with the increasing power of supercomputers, the forecast skill of numerical weather models extends to about only six days...

List Of Weather Records ... Many weather records are measured under specific conditions—such as surface temperature and wind speed—to keep consistency among measurements around the Earth... Each of these records is understood to be the record value officially observed, as these records may have been exceeded before modern weather instrumentation was invented, or in remote areas without an official weather station...

Weather Satellite ... For example, the 2002 oil spill off the northwest coast of Spain was watched carefully by the European ENVISAT, which, though not a weather satellite, flies an instrument (ASAR) which can see changes in the sea surface... Collectively, weather satellites flown by the U. S., Europe, India, China, Russia, and Japan provide nearly continuous observations for a global weather watch...

Wind Wave Model ... For the specific case of predicting wind wave statistics on the ocean, the term ocean surface wave model is used. Other applications, in particular coastal engineering, have led to the developments of wind wave models specifically designed for coastal applications...

Ensemble Forecasting ... Considering the problem of numerical weather prediction, ensemble predictions are now commonly made at most of the major operational weather prediction facilities worldwide, including the National Centers for Environmental Prediction (US), the European Centre for Medium-Range Weather Forecasts (ECMWF), the United Kingdom Met Office, Meteo France, Environment Canada, the Japanese Meteorological Agency, the Bureau of Meteorology (Australia), the China Meteorological Administration, the Korea Meteorological Administration, and CPTEC (Brazil)... History See also: History of numerical weather prediction As proposed by Edward Lorenz in 1963, it is impossible for long-range forecasts—those made more than two weeks in advance—to predict the state of the atmosphere with any degree of skill, owing to the chaotic nature of the fluid dynamics equations involved... It was not until 1992 that ensemble forecasts began being prepared by the European Centre for Medium-Range Weather Forecasts and...

Weather Front ... Surface weather analysis A surface weather analysis is a special type of weather map which provides a view of weather elements over a geographical area at a specified time based on information from ground–based weather stations... Weather maps are created by plotting or tracing the values of relevant quantities such as sea-level pressure, temperature, and cloud cover onto a geographical map to help find synoptic scale features such as weather fronts... Surface weather analyses have special symbols which show frontal systems, cloud cover, precipitation, or other important information...

Atmospheric Model ... For specific locations, model output statistics use climate information, output from numerical weather prediction, and current surface weather observations to develop statistical relationships which account for model bias and resolution issues...