A sudden, significant increase in station pressure.

Same as rain gauge.

Instrument used to measure the amount of water evaporated from the soil surface during a given time interval.

The processing of the form or mode of a signal so as to make it intelligible to, or compatible with, a given device.

Apparatus designed to measure the amount of precipitation falling in the form of snow. The device determines the weight of the snow or the volume of water after the snow melts.

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 ...

See radiation shield.

Amount of water, expressed as a depth or as a mass, which would be obtained if all the water vapor in a specified column of the atmosphere were condensed and precipitated.

Same as evaporative power.

In a radiosonde observation, a level (other than a standard level) for which values of pressure, temperature, and humidity are reported because temperature and/or humidity data at that level is sufficiently important or unusual to warrant the attention of ...

Psychrometer to which a small chain or rotary handle is attached so that the observer can rotate the instrument rapidly to properly ventilate the thermometer bulbs.

Contraction for pilot balloon observation.

The amount of precipitation falling in one day, or other specified period, that is likely to be equalled or exceeded in any given place only once in a century. That is, a precipitation amount that has a return period of 100 years.

Snow gauge composed of a metal cylinder, closed at one end, used to obtain a sample of snow from which the water is measured after melting.

Operation mode of a communication circuit in which one end can only transmit and the other end can only receive.

An aneroid barometer with a scale graduated in altitude instead of pressure units.

Radiation with wavelengths less than 4 microns.

Meteorological information issued by a watch office concerning the occurrence or forecast of weather phenomena which may affect the safety of aircraft operations.

The amount of moisture which, if available, would be removed from a given land area by evapotranspiration. Expressed in units of water depth.

An instrument for measuring differences in electric potential.