The state of the atmosphere, mainly with respect to its effects upon life and human activities. As distinguished from climate, weather consists of the short-term (minutes to months) variations of the atmosphere.

The difference between amounts of precipitation and runoff for a given storm. It is that portion of the precipitation that remains in the basin as soil moisture, surface storage, ground water, etc.

A medium-sized instrument shelter. It is a white louvered box with a flat double to of and is mounted four feet above the ground on a four-legged stand.

The process by which small particles suspended in a medium of a different refractive index diffuse a portion of the incident radiation in all directions. In scattering no energy transformation results, only a change in the spatial distribution of the radi ...

A hydrometeor consisting of a visible aggregate of minute water and/or ice particles in the atmosphere above the earth's surface. Cloud differs from fog only in that the latter is, by definition, in contact with the earth's surface.

A precipitation amount of less than 0.005 inches. Also, the record made by any self-registering instrument.

Wind with a speed between 28 and 33 knots (32 and 38 mph); Beaufort scale number 7.

A cone-tipped metal rod designed to be driven downward into deposited snow or firn. The measured amount of force required to drive the rod a given distance is an indication of the physical properties of the snow or firn.

A method of upper air observation consisting of an evaluation of the wind speed and direction, temperature, pressure, and humidity aloft by means of a balloon-borne radiosonde tracked by radar or a radio theodolite.

Video Display Terminal. An input and display device which includes a keyboard and a screen and allows a human to communicate with a computer.

A protocol similar to RS232 which permits data interchange on multidrop networks of up to 32 nodes using a single twisted pair cable. In order for this protocol to be used, each device on a network must have some level of intelligence in order establish o ...

Any source of radiant energy, especially electromagnetic energy.

An instrument which measures the transmissivity of the atmosphere between two points for the determination of visual range.

Amount of solar radiation incident, per unit area and time, on a surface which is perpendicular to the radiation and is situated at the outer limit of the atmosphere, the earth being at its mean distance from the sun. It equals approximately 2.00 ly/ min ...

Anemometer whicb measures wind speed by measuring the degree of cooling of a metal wire heated by an electric current. A type of cooling power anemometer.

The combined processes by which water is transferred from the earth's surface to the atmosphere: evaporation of liquid or solid water plus transpiration from plants.

An early and once universal name for the mercury barometer.

Operation mode of a communication circuit in which one end can only transmit and the other end can only receive.

Area of a computer or other device where various logic and control elements are interconnected. Often a printed circuit board into which other circuit boards plug at right angles.

A graphical aid used in the reduction of data from a winds aloft observation.