Temperature to which absolutely dry air would have to be brought in order for it to have the same density as moist air, considered at the same pressure.

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

That horizontal wind velocity at which the Coriolis acceleration exactly balances the horizontal pressure force. It is directed along contour lines or isobars.

The temperature at which a solid substance undergoes fusion, i.e. melts, changes from solid to liquid form. All substances have their characteristic melting points. For very pure substances the temperature range over which the process of fusion occurs is ...

An instrument for measuring differences of electric potential.

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

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.

The direction, with respect to magnetic north, from which the wind is blowing. Distinguish from true wind direction.

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

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.

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

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

A type of pressure-plate anemometer in which the plate, restrained by a stiff spring, is held perpendicular to the wind. The wind-activated motion of the plate is measured electrically. The natural frequency of this system can be made high enough so that ...

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

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.

See evaporative opportunity.