See calorie.

A series of Nansen-bottle water samples and associated temperature observations resulting from one release of a messenger.

Same as fogbow.

A curve showing the variation of temperature with height in the free air. See lapse rate.

A fabric cone attached to a metal ring and used to indicate wind direction. often at airfields.

The lowest temperature that can be obtained on a wet-bulb thermometer in any given sample of air. Obtained by evaporation of water (or ice) from the muslin wick. Used in computing dew point and relative humidity.

An aneroid barometer arranged so that the deflection of the aneroid capsule actuates a pen which graphs a record on a rotating drum. Sometimes called aneroidograph.

The stage on a fixed river gauge at which it is necessary to begin issuing warnings or river forecasts if adequate precautionary measures are to be taken before flood stage is reached.

A contact anemometer connected to an electrical circuit which is so arranged that the average wind speed is indicated.

NEXt Generation RADar. A NWS network of about 140 Doppler radars operating nationwide.

An instrument for determining the direction of cloud motion. There are two basic designs of nephoscope, the directvision nephoscope and the mirror nephoscope.

The level at which ice crystals and snowflakes melt as they descend through the atmosphere.

The distance or length of flow of the air past a point during a given interval of time.

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

Solar radiation scattered by particles in the atmosphere.

A wind blowing in a direction perpendicular to the course of a moving object.

Electromagnetic radiation of shorter wavelength than visible radiation but longer than x-rays, between 0.02 and 0.4 micron (200 and 4000 angstrom).

The unit of force in the centimeter-gram-second system of physical units, i.e. one gm cm per sec2, equal to 7.233 x 10-5 poundal.

A point (or line) on a scale used for reference or comparison purposes. In calibration of meteorological thermometers, for example, the fiducial points are 100

The depth of water that would result from the melting of snow or ice, assuming measurement on a horizontal surface and no infiltration or evaporation.