The center of an area of high pressure, usually accompanied by anticyclonic and outward wind flow. Also known as an anticyclone.

The volume of water required to cover one acre to a depth of one foot: 43,560 cubic feet.

The change in the measured transducer output caused by changes in ambient temperature. Usually expressed a percentage of full scale.

The difference between the solar radiation directed downward and upward; net flux of solar radiation.

Forecasting weather by the use of numerical models, run on high speed computers. Most of the NWP for the National Weather Service is done at the National Centers for Environmental Prediction (NCEP).

The time required for an instrument to register a designated percentage (frequently 90%) of a step change in the variable being measured.

A hygrometer which includes an arrangement for the time recording of atmospheric humidity.

A unit that represents one degree of deviation from a reference point in the mean daily outdoor temperature (usually 65

An up slope wind due to local surface heating. Opposite of katabatic wind.

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

The record of a barograph.

An instrument for the measurement of the net flux of downward and upward total (solar and terrestrial) radiation through a horizontal surface.

A conically shaped, copper rain gauge shield.

An instrument for measuring the frost point of the atmosphere.

Liquid water at temperatures colder than freezing.

A balloon designed to float at a constant pressure level. This may be accomplished by a pressure valve which controls the release of ballast so as to maintain flight above a selected pressure level until the supply of ballast is exhausted. See Moby Dick b ...

An instrument for measuring differences of electric potential.

In a system of moist air, the ratio of the mass of water vapor to the total volume of the system. Usually expressed as grams per cubic meter (g/m3).

See radiosonde commutator.

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 ...