A clockwise change in wind direction. Veering winds with height are indicative of warm air advection (WAA).

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 which measures the scattering function of particles suspended in a medium in order to determine the visual range through the medium. See visibility meter.

A liquid-in-glass or liquid-in-metal thermometer using mercury as the liquid.

check chamber-A chamber use to check the sensing elements of radiosonde equipment.

in United States weather observing practice, the highest "instantaneous" wind speed recorded at a station during a specified period, usually the 24-hour observation day. Therefore, a peak gust need not be a true gust of wind.

A radar which is used to obtain the azimuth elevation, and slant range of an airborne target.

Pertaining to measurements or devices in which the output varies continuously, i.e. voltage or rotation signals. Compare to digital.

Radio Direction Finder.

A temperature scale on which the freezing point of water equals 32

An instrument which automatically records the measurement of two or more meteorological elements.

A general term for atmospheric water in any of its forms, i.e. clouds, fog, hail, ice crystals, rain.

Same as precipitation- effectiveness index.

An instrument which automatically determines the size distribution of raindrops.

A seasonal wind of persistent direction, characterized by a pronounced change in direction between seasons.

Negative Vorticity Advection.

Old snow that has become granular and compacted as a result of melting and refreezing.

The component of the radiosonde which includes the modulating blocking oscillator and the radiofrequency carrier oscillator.

The measuring, transmitting, receiving, and indicating apparatus for obtaining the value of a quantity at a distance.

variable audio-modulated radiosonde developed at the Bureau of Standards and used by the United States weather services.