A self-recording instrument used on aircraft for the simultaneous recording of atmospheric pressure, temperature, and humidity.

In general, any self-recording instrument carried aloft by any means to obtain meteorological data.

The transducer's output when the maximum sensed value is applied to the transducer's input. For example, the F.S. output of a 4-20 mA transmitter is 20 mA, whereas its span is only 16mA.

Federal Aviation Administration.

A device used by oceanographers to obtain subsurface samples of sea water. The "bottle" is lowered by wire, its valves open at both ends. It is then closed in situ by allowing a weight (called a messenger) to slide down the wire and strike the reversing m ...

A recording hair hygrometer.

Precipitation composed of balls or irregular lumps of ice with diameters between 5 and 50 mm.

Electromagnetic radiation of very short wavelength. lying within the wavelength interval of 0.1 to 1.5 angstroms (between gamma rays and ultraviolet radiation). X-rays penetrate various thicknesses of all solids, and they act on photographic plates in the ...

Quantitative Precipitation Forecast.

A system in which radar techniques are used to determine the range, elevation, and azimuth of a radar target carried a!oft by a radiosonde, so that wind data may be obtained along with the other meteorological data.

A type of directional antenna used on some types of radar and radio equipment consisting of an array of elemental, single- wire dipole antennas and reflectors.

See wind vane.

Abbreviation for precipitation-evaporation ratio.

An increase or amplification. There are two general usages of the term in radar meteorology: (a) antenna gain (or gain factor) is the ratio of the power transmitted along the beam axis to that of an isotropic radiator transmitting the same total power; an ...

Abbreviation for precipitation effectiveness index.

Same as altimeter setting.

Any wind blowing down an incline. If warm, it is a foehn. If cold, it may be a fall wind or a gravity wind.

A type of cooling-power anemometer based upon the principle that the time constant of a thermometer is a function of its ventilation.

Wind with a speed between 28 and 55 knots (32 and 63 mph); Beaufort scale numbers 7 through 10.

Abbreviation for the pressure, temperature, and humidity data obtained by a radiosonde observation.