Sustained winds greater than or equal to 40 mph or gust greater than or equal to 58 mph.

Precipitation composed of liquid water drops more than 0.5 mm in diameter, failing in relatively straight, but not necessarily vertical, paths. Compare to drizzle.

An instrument for determining the dust content of a sample of air. Also spelled conimeter.

Same as wind sock.

The audio-frequency signal transmitted by the Diamond-Hinman radiosonde when the baroswitch pen passes each fifteenth contact of the commutator, up to a number determined by the design of the commutator, and each fifth contact thereafter. This signal is t ...

A pyrheliometer of the bimetallic type used to measure the intensity of direct solar radiation.

Phase Shift Keying. A form of phase modulation of a data signal performed by a modem for transmission over dedicated wire or phone lines.

Sir Napier Shaw's name for the approximate absolute temperature scale,

A measure of the amount of "spin" (or rotation) in the atmosphere.

See gust and peak gust.

Thermometer for measuring the temperature in the soil at different depths.

The maximum rate at which precipitation can pass through the surface into the soil, for a given soil in a given condition.

An instrument used to measure the amount of dew formed on a given surface.

A hygrometer using goldbeater's skin as the sensitive element. Variations of the physical dimensions of the skin caused by its hygroscopic character indicate relative humidity. (Note: Goldbeater's skin is the prepared outside membrane of the large intesti ...

A refraction phenomenon similar to a parahelion, but occurring generally at a distance of 120

A form of psychrometer with wet-bulb and dry-bulb thermometers mounted on opposite sides of a specialty designed graph of the psychrometric tables. It is so arranged that the intersections of two curves determined by the wet-bulb and dry-bulb readings -yi ...

The process in which incident radiation is retained by a substance. A further process always results from absorption.

A form of data transmission in which the bits of each character are all sent simultaneously, resulting in extremely fast communication but requiring a communication path for each bit. Compare to serial data transmission.

Abbreviation for precipitation-evaporation ratio.

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.