The atmospheric pressure at the level of the barometer. May or may not be the same as station pressure.

An instrument used to measure the water vapor content of the air. A type of hygrometer. It consists of a wet-bulb and a dry-bulb thermometer. See aspiration psychrometer, Assmann psychrometer. hygrodeik, sling psychrometer.

Winds which, over a small area, differ from those which would be appropriate to the general pressure distribution.

A type of climatic diagram whose coordinates are some form of temperature vs. a form of humidity or precipitation.

A constant which describes the performance of a wind vane in response to a step change in wind direction. It is calculated from the relative amount of overshoot on two successive swings (half cycles) of a decaying oscillation. This specification is dimens ...

An instrument for measuring temperature by utilizing the variation of the physical properties of substances according to their thermal states. Thermometers may be classified into types according to their construction; deformation thermometer, electrical t ...

An anemometer in which the sensor rotation is transmitted to a mechanical counter which directly integrates the air movement past the sensor. Used to determine total air passage (wind run). Average wind speed can be calculated from the difference between ...

National Centers for Environmental Prediction. Central computer and communications facility of the National Weather Service; located in Washington, DC.

Same as marine rainbow.

See aneroid capsule.

A vector term which includes both wind speed and wind direction.

A recording siphon barometer.

The atmospheric pressure at mean sea level either directly measured by stations at sea level or empirically determined from the station pressure and temperature by stations not at sea level. Used as a common reference for analyses of surface pressure patt ...

The general term for dry atmospheric suspensoids, including dust, haze, smoke. and sand. Compare to hydrometeor.

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 ...

Of or pertaining to the air, atmosphere, or aviation. Also, same as antenna.

A c.g.s. (centimeter-gram-second) unit of mass. Originally defined as the mass of 1 cubic centimeter of water at 4

The range through which the input may be varied without initiating a response. Usually expressed as a percentage of full-scale range.

Same as geostrophic wind level.

A protocol similar to RS232 which makes use of differential transmission to provide high speed data transmission over significantly longer distances.