A thermograph in which ventilation is provided by a suction fan.

In general, pertaining to or affording an overall view. In meteorology, this term has become somewhat specialized in referring to the use of meteorological data obtained simultaneously over a wide area for the purpose of obtaining a comprehensive and near ...

Same as wind sock.

See evaporation pan.

in United States weather observing practice, the highest "instantaneous" wind speed recorded at a station during a specified period, usually the 24-hour observation day. Therefore, a peak gust need not be a true gust of wind.

A graphical aid used in fire weather forecasting to calculate the degree of forest-fire danger (or burning index). Commonly in the form of a circular slide rule, the firedanger meter relates numerical indices of (a) the seasonal stage of foliage, (b) the ...

Same as mirror nephoscope.

An empirical curve relating stream discharge or stage at a point on a stream to discharge or stage at one or more upstream points and, possibly. to other parameters. Also called stage relation.

A general term for instruments designed to measure the amount of cloudiness.

A hypothetical "body" whose surface absorbs no electromagnetic radiation of any wavelength. An idealization exactly opposite to that of the black body. In nature, no true white bodies are known. Moist white pigments exhibiting high reflectivity for visibl ...

A decrease in the central pressure of a pressure system. Usually applied to a low rather than to a high.

A rain gauge capable of measuring very small amounts of precipitation. Also called micropluviometer, trace recorder.

Any one of numerous devices for the measurement of either speed alone or of both direction and speed (set and drift) in flowing water.

Part of a computer word that has meaning in itself, often, a byte.

The standard deviation (positive square-root of the variation) of the errors associated with physical measurements of an unknown quantity, or statistical estimates of an unknown parameter or of a random variable.

Video Display Terminal. An input and display device which includes a keyboard and a screen and allows a human to communicate with a computer.

Difference between the instantaneous wind velocity at a point and the mean wind velocity taken over a given time interval. Also called fluctuation velocity.

General term for an instrument used to make direct measurements of visual range or measurements of the physical characteristics of the atmosphere which determine the visible range.

A very sensitive electrostatic electrometer for measuring small potential differences.

A radiosonde which transmits the indication of the meteorological sensing elements in the form of a code consisting of combinations of dots and dashes.