Any wind blowing down an incline. If warm, it is a foehn. If cold, it may be a fall wind or a gravity wind.

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 ...

See hurricane beacon.

A Sunshine recorder of the type in which the time scale is supplied by the motion of the sun. The instrument, which is pointed at the celestial pole, consists of a hemispherical mirror mounted externally on the optical axis of a camera. The lens of the ca ...

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

A thermometer whose sensitive element has been made to resemble a black body by covering it with lamp black. The thermometer is placed in an evacuated transparent chamber which is maintained at a constant temperature. The instrument responds to insolation ...

A strong wind characterized by a sudden onset, a duration on the order of minutes, and a rather sudden decrease in speed.

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

In folklore, a name for wind.

Wind with a speed between 56 and 63 knots (64 and 72 mph); Beaufort scale number 11.

A spring which is designed to achieve a fixed spring constant over a wide temperature range. Usually, this involves an alloy with high nickel content such as Ni-Span C. It is common for these springs to be stress relieved at elevated temperature after for ...

An instrument for measuring the difference between incoming and outgoing terrestrial radiation.

Closed, curved, flexible tube of elliptic cross section which is deformed, according to type, by variations of atmosphere spheric pressure or temperature and so provides a measurement of the particular parameter.

The record made by a hygrograph.

Electromagnetic radiation lying in the wavelength interval between 0.8 micron and I millimeter. At the lower limit of this interval, the infrared radiation spectrum is bounded by visible radiation, while on its upper limit it is bounded by microwave radia ...

Pertaining to rain, or more broadly, to precipitation.

That stage, on a fixed river gauge, at which overflow of the natural banks of the stream begins to cause damage in any portion of the reach for which the gauge is used as an index.

Very small precipitation drops (diameters less than 0.5 mm) that appear to float with air currents while falling in an irregular path. Unlike fog droplets, drizzle falls to the ground.

See hydrologic accounting.

That part of an audio-modulated radiosonde consisting of the baroswitch, the sensing elements, the reference elements, and the relay.