Snow shower, particularly of a very light and brief nature.

A magnetometer of the electromagnetic type which is used to measure the horizontal intensity of the earth's magnetic field.

An instrument for measuring the intensity of light or the relative intensity of a pair of lights. Also called an illuminometer. If the instrument is designed to measure the intensity of light as a function of wavelength, it is called a spectrophotometer. ...

The officially designated elevation of an airport above mean sea level, taken as the highest point on any of the runways of the airport. Same as airport elevation.

An atmometer consisting of a porous porcelain or ceramic container connected to a calibrated reservoir filled with distilled water. Evaporation is determined by the depletion of water in the reservoir.

Same as wind sock.

Similar to the spectroheliograph, but used for visual instead of photographic purposes.

A type of hygrometer which measures the water vapor content of the atmosphere by means of the absorption of vapor by a hygroscopic chemical.

Determined by weighing a special type of wooden stick that has been exposed in the woods, its weight being proportional to its contained water.

Navy Operational Global Atmospheric Prediction System. A global meteorological model operated by the Department of Defense.

Temperature of equilibrium between the liquid and vapor phases of a substance at a given pressure.

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.

The nautical mile is closely related to the geographical mile which is defined as the length of one minute of arc on the earth's equator. By international agreement, the nautical mile is now defined as 1852 meters.

Readily taking up and retaining moisture.

A continuous-recording barometer.

General term for an instrument which records the vertical electric current in the atmosphere.

A wooden enclosure about sixteen feet square and eight feet high with a precipitation gauge at its center. The function of the fence is to minimize eddies around the gauge and thus insure a catch that is representative of the actual rainfall or snowfall.

An instrument designed to record the duration of sunshine at a given location without regard to intensity. See Campbell- Stokes recorder, Jordan sunshine recorder, Marvin sunshine recorder, Pers sunshine recorder.

Same as mercury barometer.

An instrument which measures the spectral distribution of the intensity of direct solar radiation.