Weather forecasting and prediction

• Main Authors: Joseph P. Gerrity, John R. Gyakum, Richard A. Anthes, Lance F. Bosart, Keith A. Browning, Edward A. O'Lenic
• Format: Reference Entry
• Language: English
• DOI: 10.1036/1097-8542.742600

Processes for formulating and disseminating information about future weather conditions based upon the collection and analysis of meteorological observations. Weather forecasts may be classified according to the space and time scale of the predicted phenomena. Atmospheric fluctuations with a length of less than 100 m (330 ft) and a period of less than 100 s are considered to be turbulent. Prediction of turbulence extends only to establishing its statistical properties, insofar as these are determined by the thermal and dynamic stability of the air and by the aerodynamic roughness of the underlying surface. The study of atmospheric turbulence is called micrometeorology; it is of importance for understanding the diffusion of air pollutants and other aspects of the climate near the ground. Standard meteorological observations are made with sampling techniques that filter out the influence of turbulence. Common terminology distinguishes among three classes of phenomena with a scale that is larger than the turbulent microscale: the mesoscale, synoptic scale, and planetary scale.