An effect noted primarily in wet snow conditions when snow clings to the sides of a precipitation gauge and gradually accumulates until the gauge orifice is capped with accumulated snow. This effect can be minimized by using large collectors, and wind scr ...

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

A device for measuring the frequency of occurrence of atmospherics whose intensity is greater than a predetermined level.

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

Automated Weather Observing Station. A self-contained weather station designed to make aviation weather observations without operator involvement.

Same as geostrophic wind level.

A radiosonde which is dropped by parachute from an aircraft for the purpose of obtaining soundings of the atmosphere below.

In folklore, a name for rain.

A system of designating meteorological observing stations by number. established and administered by the World Meteorological Organization. Under this scheme, specified areas of the word are divided into "blocks" each bearing a two-number designator. Stat ...

The combined processes by which water is transferred from the earth's surface to the atmosphere: evaporation of liquid or solid water plus transpiration from plants.

Any device or instrument for measuring salinity, especially one based on electrical conductivity methods.

Federal Aviation Administration.

The standard deviation (positive square-root of the variation) of the errors associated with physical measurements of an unknown quantity, or statistical estimates of an unknown parameter or of a random variable.

The upper surface of a column of liquid.

The transducer of any hygrometer, i.e. that part of a hygrometer that quantitatively "senses" atmospheric water vapor.

The difference between the air temperature and the dew-point. Also called dew-point deficit, dew-point depression.

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 ...

Name given to the unit of pressure in the International System of Units (SI). Equal to 1 newton/meter2 or 0.01 millibar.

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

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