Difference between the temperatures of the dry-bulb and the wet-bulb thermometers of a psychrometer.

That part of snow melt that reaches stream channels as runoff.

The gravity flow of water within soil.

A radiosonde whose carrier wave is switched on and off in such a manner that the interval of time between the transmission of signals if a function of the magnitude of the meteorological elements being measured.

Capacity of a soil or other surface to be penetrated by water sinking into the ground under the force of gravity. It thus expresses the rate of percolation.

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.

Name given to the unit of pressure in the International System of Units (SI). Equal to 1 newton/meter2 or 0.01 millibar.

The wind speed and direction at various levels in the atmosphere above the level reached by surface weather observations.

A unit of energy defined as the heat required to raise the temperature of one pound of water one degree Fahrenheit. It is equal to 252.1 calories or to 1055 joules.

A temperature telemeter.

In general, any object that reflects incident energy. Usually it is a device designed for specific reflection characteristics.

An absolute temperature scale with the degree of the Fahrenheit scale and the zero point of the Kelvin scale. The freezing point of water equals 491.69

Nested Grid Model generated every 12 hours by NCEP.

An instrument used for measuring geometric angles. See radio direction-finder.

An instrument for measuring temperature by utilizing the variation of the physical properties of substances according to their thermal states. Thermometers may be classified into types according to their construction; deformation thermometer, electrical t ...

Same as fogbow.

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

See calorie.

An instrument for measuring differences of electric potential.

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