An atmometer which uses a filter paper disc as the evaporating element. The amount of water evaporated through the paper is read at the graduated tube reservoir.

A recording weight barometer.

Growth of a cloud or precipitation particle by the collision and union of a frozen particle with a super-cooled water drop.

A recording pressure-tube anemometer in which the wind scale of the float manometer has been made linear by the use of springs, i.e. Dines anemometer.

An absolute temperature scale with the ice point of pure water defined as 273.16 K. The size of the degree is the same as on the Celsius scale, and the zero point is absolute zero.

Meteorological information issued by a watch office concerning the occurrence or forecast of weather phenomena which may affect the safety of aircraft operations.

See foehn.

A rain gauge capable of measuring very small amounts of precipitation. Also called micropluviometer, trace recorder.

An instrument for measuring the frost point of the atmosphere.

A set of rules or conventions used to standardize data transfer between devices.

A large plastic constant-level balloon for duration flying at very high altitudes.

A temperature scale based on absolute zero. Same as Kelvin temperature scale.

An anemometer utilizing the principle that the pitch of the aeolian tones generated by air moving past an obstacle is a function of the speed of the air. Largely a curiosity and has been put to no practical application in modem meteorology.

The total infrared radiation emitted from the earth's surface. To be carefully distinguished from atmospheric radiation, effective terrestrial radiation, and insolation.

A measure of long-term precipitation effectiveness. The ratio of the normal annual rainfall to the normal annual evaporation.

A thermometer with a muslin-covered bulb which is moistened. used to measure wet-bulb temperature.

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

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 system of designating meteorological observing stations by number. established and administered by the World Meteorological Organization. Under this scheme, specified areas of the word are divided into "blocks" each bearing a two-number designator. Stat ...

Overflowing by water of the normal confines of a stream or other body of water, or accumulation of water by drainage over areas which are not normally submerged.