Name sometimes given to a transmissometer.

Wind with a speed between 4 and 6 knots (4 and 7 mph), Beaufort scale number 2.

An instrument developed by K. Angstrom for measuring the effective terrestrial radiation. It consists of four manganin strips, of which two are blackened and two are polished. The blackened strips are allowed to radiate to the atmosphere while the polishe ...

Physical equipment used in data processing. Compare to firmware, software.

A hygrometer which uses a transducing element whose electrical properties are a function of atmospheric water vapor content. The humidity strip and carbon-film hygrometer element are examples of such a transducer.

An optical instrument which consists of a sighting telescope mounted so that it is free to rotate around horizontal and vertical axes, with graduated scales so that the angles of rotation may be measured. Used to observe the motion of a pilot balloon.

A thin metal disc partially evacuated of air used to measure atmospheric pressure by measuring its expansion and contraction.

Solar and terrestrial radiation directed upward (away From the earth's surface); outgoing radiation.

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 ...

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

An approximation to the complete equations describing atmospheric motion in which only the terms most important for the growth and decay of synoptic scale extratropical weather systems (i.e., the large areas of high and low pressure seen on weather maps) ...

Same as mirror nephoscope.

The older name for the Celsius temperature scale. Officially abandoned by international agreement in 1948, but still in common use.

Interational thermometric scale on which the freezing point of water equals 0

Any quantity, such as force velocity, or acceleration, which has both magnitude and direction at each point in space, as opposed to scalar which has magnitude only. Such a quantity may be represented geometrically by an arrow of length proportional to its ...

The ratio of the amount of electromagnetic radiation reflected by a body to the amount incipient upon it, commonly expressed as a percentage. The albedo is to be distinguished from the reflectivity, which refers to one specific wavelength.

Same as wind sock.

An atmometer consisting of a porous porcelain or ceramic container connected to a calibrated reservoir filled with distilled water. Evaporation is determined by the depletion of water in the reservoir.

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.

National Weather Service. Administered by the U.S. Department of Commerce.