A thermometer consisting of a clock mechanism the speed of which is a function of temperature.

A very sensitive electrostatic electrometer for measuring small potential differences.

The height of the cloud base above the local terrain.

A type of precipitation composed of unbranched crystals in the form of needles, columns, or plates. Usually has a very slight downward motion and may fall from a cloudless sky.

Situated on the side from which the wind blows.

A type of cloud height indicator which uses a searchlight to project vertically a narrow beam of light onto the cloud base. The height of the cloud is determined using a clinometer, located at a known distance from the ceiling light, to measure the angle ...

A instrument designed to study small fluctuations of some quantity. The microbarograph is an example of a recording pressure variometer.

See radiosonde commutator.

A rain gauge or array of rain gauges designed to measure the inclination and direction of falling rain.

See feed.

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

A device for measuring sea-surface waves. It consists of a weighted pole below which a disk is suspended at a depth sufficiently deep for the wave motion associated with deepwater waves to be negligible. The pole will then remain nearly as if anchored to ...

Thermometer used for measuring the highest temperature attained during a given interval of time, for example, a day.

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

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 ...

Abbreviation for Instrument Flight Rules, but commonly used to refer to the weather and/or flight conditions to which these rules apply, i.e. low visibility.

An absolute pyhrliometer, developed by C.G. Abbott, in which the radiation-sensing element is a blackened water-calorimeter.

Any sudden and heavy rain, almost always of the shower type.

An instrument which determines the black-body temperature of a substance by measuring its thermal radiation.

Abbreviation for visual flight rules, but commonly used to refer to the relatively favorable weather and/or flight conditions to which these rules apply.