A weather station is a facility, either on land or sea, with instruments and equipment for measuring atmospheric conditions to provide information for weather forecasts and to study the weather and climate. The measurements taken include temperature, atmospheric pressure, humidity, wind speed, wind direction, and precipitation amounts. Wind measurements are taken with as few other obstructions as possible, while temperature and humidity measurements are kept free from direct solar radiation, or insolation. Manual observations are taken at least once daily, while automated measurements are taken at least once an hour. Weather conditions out at sea are taken by ships and buoys, which measure slightly different meteorological quantities such as sea surface temperature (SST), wave height, and wave period. Drifting weather buoys outnumber their moored versions by a significant amount.
In meteorology, lee waves are atmospheric stationary waves. The most common form is mountain waves, which are atmospheric internal gravity waves. These were discovered in 1933 by two German glider pilots, Hans Deutschmann and Wolf Hirth, above the Krkonoše. They are periodic changes of atmospheric pressure, temperature and orthometric height in a current of air caused by vertical displacement, for example orographic lift when the wind blows over a mountain or mountain range. They can also be caused by the surface wind blowing over an escarpment or plateau, or even by upper winds deflected over a thermal updraft or cloud street.
The Storm Prediction Center (SPC) is a US government agency that is part of the National Centers for Environmental Prediction (NCEP), operating under the control of the National Weather Service (NWS), which in turn is part of the National Oceanic and Atmospheric Administration (NOAA) of the United States Department of Commerce (DoC).
A derecho is a widespread, long-lived, straight-line wind storm that is associated with a fast-moving group of severe thunderstorms known as a mesoscale convective system.
Numerical weather prediction (NWP) uses mathematical models of the atmosphere and oceans to 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.
Convective inhibition is a numerical measure in meteorology that indicates the amount of energy that will prevent an air parcel from rising from the surface to the level of free convection.
A tropical cyclone forecast model is a computer program that uses meteorological data to forecast aspects of the future state of tropical cyclones. There are three types of models: statistical, dynamical, or combined statistical-dynamic. Dynamical models utilize powerful supercomputers with sophisticated mathematical modeling software and meteorological data to calculate future weather conditions. Statistical models forecast the evolution of a tropical cyclone in a simpler manner, by extrapolating from historical datasets, and thus can be run quickly on platforms such as personal computers. Statistical-dynamical models use aspects of both types of forecasting. Four primary types of forecasts exist for tropical cyclones: track, intensity, storm surge, and rainfall. Dynamical models were not developed until the 1970s and the 1980s, with earlier efforts focused on the storm surge problem.
In atmospheric science, an atmospheric model is a mathematical model constructed around the full set of primitive, dynamical equations which govern atmospheric motions. It can supplement these equations with parameterizations for turbulent diffusion, radiation, moist processes, heat exchange, soil, vegetation, surface water, the kinematic effects of terrain, and convection. Most atmospheric models are numerical, i.e. they discretize equations of motion. They can predict microscale phenomena such as tornadoes and boundary layer eddies, sub-microscale turbulent flow over buildings, as well as synoptic and global flows. The horizontal domain of a model is either global, covering the entire Earth, or regional (limited-area), covering only part of the Earth. The different types of models run are thermotropic, barotropic, hydrostatic, and nonhydrostatic. Some of the model types make assumptions about the atmosphere which lengthens the time steps used and increases computational speed.
The Weather Research and Forecasting (WRF) Model is a numerical weather prediction (NWP) system designed to serve both atmospheric research and operational forecasting needs. NWP refers to the simulation and prediction of the atmosphere with a computer model, and WRF is a set of software for this. WRF features two dynamical (computational) cores, a data assimilation system, and a software architecture allowing for parallel computation and system extensibility. The model serves a wide range of meteorological applications across scales ranging from meters to thousands of kilometers.
In weather forecasting, model output statistics (MOS) is a multiple linear regression technique in which predictands, often near-surface quantities, 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.
The Great Salt Lake effect is a small but detectable influence on the local climate and weather around the Great Salt Lake in Utah, United States. In particular, snowstorms are a common occurrence over the region and have major socio-economic impacts due to their significant precipitation amounts. The Great Salt Lake almost never freezes and can warm rapidly, which allows lake enhanced precipitation to occur from September through May. Lake-enhanced snowstorms are often attributed to creating what is locally known as "The Greatest Snow on Earth".
In meteorology and climatology, a mesonet, portmanteau of mesoscale network, is a network of automated weather and, often also including environmental monitoring stations, designed to observe mesoscale meteorological phenomena and/or microclimates.
Joseph G. Galway, was an American meteorologist pioneering in the fields of severe convective storm forecasting and research. He was one of the first forecasters for the Severe Local Storms Unit and the National Severe Storms Forecast Center, and developed widely used synoptic predictors associated with severe thunderstorms and tornadoes, such as the jet streak and lifted index.
Ronald William Przybylinski was an American meteorologist who made important contributions to understanding of bow echoes, mesovortices, related quasi-linear convective system (QLCS) structures and processes, as well as QLCS related tornadoes. He also was an expert on technical aspects of weather radar and applications to both operational meteorology and research.
The Alberta Hail Project was a research project sponsored by the Alberta Research Council and Environment Canada to study hailstorm physics and dynamics in order to design and test means for suppressing hail. It ran from 1956 until 1985. The main instrument in this research was an S-band circularly polarized weather radar located at the Red Deer Industrial Airport in central Alberta, Canada.
A wake low, or wake depression, is a mesoscale low-pressure area which trails the mesoscale high following a squall line. Due to the subsiding warm air associated with the system's formation, clearing skies are associated with the wake low. Once difficult to detect in surface weather observations due to their broad spacing, the formation of mesoscale weather station networks, or mesonets, has increased their detection. Severe weather, in the form of high winds, can be generated by the wake low when the pressure difference between the mesohigh preceding it and the wake low is intense enough. When the squall line is in the process of decay, heat bursts can be generated near the wake low. Once new thunderstorm activity along the squall line concludes, the wake low associated with it weakens in tandem.
The Oklahoma Mesonet is a network of environmental monitoring stations designed to measure the environment at the size and duration of mesoscale weather events. The phrase "mesonet" is a portmanteau of the words mesoscale and network. In meteorology, “mesoscale” refers to weather events that range in size from approximately 1 mile (1.6 km) to 150 miles (240 km) and can last from several minutes to several hours. Mesoscale events include thunderstorms, wind gusts, heat bursts, and dry lines. Without densely spaced weather observations, these mesoscale events might go undetected. In addition to surface weather observations, Oklahoma Mesonet stations also include environmental data such as insolation and soil conditions.
The history of numerical weather prediction considers how current weather conditions as input into mathematical models of the atmosphere and oceans to predict the weather and future sea state has changed over the years. Though first attempted manually in the 1920s, it was not until the advent of the computer and computer simulation that computation time was reduced to less than the forecast period itself. ENIAC was used to create the first forecasts via computer in 1950, and over the years more powerful computers have been used to increase the size of initial datasets as well as include more complicated versions of the equations of motion. The development of global forecasting models led to the first climate models. The development of limited area (regional) models facilitated advances in forecasting the tracks of tropical cyclone as well as air quality in the 1970s and 1980s.
The Jule G. Charney Award is the American Meteorological Society's award granted to "individuals in recognition of highly significant research or development achievement in the atmospheric or hydrologic sciences". The prize was originally known as the Second Half Century Award, and first awarded to mark to fiftieth anniversary of the society.
Project NIMROD was a meteorological field study of severe thunderstorms and their damaging winds conducted by the National Center for Atmospheric Research (NCAR). It took place in the Greater Chicago area from May 15 to June 30, 1978. Data collected was from single cell thunderstorms as well as mesoscale convective systems, such as bow echoes. Using Doppler weather radars and damage clues on the ground, the team studied mesocyclones, downbursts and gust fronts. NIMROD was the first time that microbursts, very localized strong downdrafts under thunderstorms, were detected; this helped improve airport and public safety by the development of systems like the Terminal Doppler Weather Radar and the Low-level windshear alert system.
