The volume of water required to cover one acre to a depth of one foot: 43,560 cubic feet.

A plastic molding component formed by the reaction of phenol and formaldehyde. It can be heavily reinforced or "filled" with glass fibers or other materials. Phenolics are known for their high impact strength, excellent wear characteristics, and dimension ...

An air-launched balloon designed to be released in the eye of a tropical cyclone, float within the eye at predetermined levels, and transmit radio signals for RDF positioning.

A mercury barometer which measures atmospheric pressure by weighing the mercury in the column or cistern.

In nautical terminology, a contraction for "weather glass" (a mercury barometer).

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.

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

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.

film hygrometer element-An electrical hygrometer element constructed of a plastic strip coated with a film of carbon black dispersed in a hygroscopic binder. Variations in atmospheric moisture content vary the volume of the binder and thus change the resi ...

A photoelectric spectrophotometer which is used in the determination of the ozone content of the atmosphere.

An optical instrument which consists of a sighting telescope mounted so that it is free to rotate around horizontal and vertical axes, with graduated scales so that the angles of rotation may be measured. Used to observe the motion of a pilot balloon.

See foehn.

The humidity transducinu element in a Diamond-Hinman radiosonde. Also called electrolytic strip.

The cardinal points of the compass, i.e. north, south, east, west.

The water portion of the earth as distinguished from the solid part, called the lithosphere, and from the gaseous outer envelope, called the atmosphere.

A forecast of weather elements of particular interest to aviation; including ceiling, visibility, upper winds, icing, turbulence, precipitation types, and storms.

A wind vane used to obtain the horizontal and vertical components of the wind.

Frozen or partly frozen rain.

An area of low atmospheric pressure which has a closed circulation that is cyclonic (counterclockwise in northern hemisphere and clockwise in southern hemisphere).

Same as aneroid barometer. Holostelic means wholly made of solids, while aneroid means devoid of liquid.