A strong wind characterized by a sudden onset, a duration on the order of minutes, and a rather sudden decrease in speed.

The meteorological visual range, which can be estimated from the average extinction coefficient using the Koschmieder equation.

Wind with a speed between 17 and 21 knots (19 and 24 mph); Beaufort scale number 5.

The audio-frequency signal transmitted by the Diamond-Hinman radiosonde when the baroswitch pen passes each fifteenth contact of the commutator, up to a number determined by the design of the commutator, and each fifth contact thereafter. This signal is t ...

A type of atmometer. It is a pan used in the measurement of the evaporation of water into the atmosphere. The NWS Class A pan is a cylindrical container 48 inches in diameter and 10 inches deep.

Overflowing by water of the normal confines of a stream or other body of water, or accumulation of water by drainage over areas which are not normally submerged.

Solar and terrestrial radiation directed downwards (towards the earth's surface); incoming radiation.

Particle on which the freezing of water occurs.

For a given location, a measure of the long-range effectiveness of precipitation in promoting plant growth. Also called precipitation-evaporation index.

A hypothetical body which absorbs some constant fraction, between zero and one, of all electromagnetic radiation incident upon it, which fraction is the absorptivity and is independent of wavelength. Compare to black body, white body.

A term used to describe a sensor (or sensors), the associated transducer(s), and the data readout or recording device.

Same as Aeolian.

Instrument for measuring the mean intensity of glo global solar radiation (direct and diffuse) near the earth's surface in a specified time interval.

A fixed support for mounting maximum and minimum thermometers of the liquid-in-glass type. The support holds the thermometers at the correct operating attitude and also permits their rotation for resetting when desired.

For a given locality and month, an empirical expression devised for the purpose of classifying climates numerically on the basis of precipitation and evaporation.

Same as dew-point hygrometer.

A unit of luminous flux. The lumen is equal to the luminous flux radiated into a unit solid angle (steradian) from a small source having a luminous intensity of one candle. An ideal source possessing an intensity of one candle in every direction would rad ...

Radiation coming from the solid angle of the sun's disc, as opposed to diffuse sky radiation, effective terrestrial radiation, or radiation from any other source. Direct solar radiation is measured by pyrheliometers.

Wind with a speed between 34 and 40 knots (39 and 46 mph); Beaufort scale number 8.

A device that allows a terminal or computer at one location to communicate with a terminal or computer at a distant location via wire or phone lines.