A measure, proposed by Angstrom, of the precipitation effectiveness of a region.

A line drawn through geographical points where a given seasonal biological event occurs on the same date.

A device for measuring the height of tide. It may be simply a graduated staff in a sheltered location where visual observations can be made, or it may consist of an elaborate recording instrument (sometimes called a marigraph) making a continuous graphic ...

Abbreviation for precipitation-evaporation quotient.

An anemometer which measures wind speed by means of the properties of wind-borne sound waves. It operates on the principle that the propagation velocity of a sound wave in a moving medium is equal to the velocity of sound with respect to the medium plus t ...

A forecast of the expected stage or discharge at a specified time, or of the total volume of flow within a specified Interval of time, at one or more points along a stream.

An Instrument used to determine dew point.

A local variation of the wind vector or any of its components in a given direction.

Same as contact anemometer.

Programmable Read-Only Memory. Read-only memory which can be programmed by the user using a special hardware programmer.

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 aviation weather forecast for a specific flight.

An instrument resulting from the combination of a thermograph and a hygrograph and furnishing, on the same chart, simultaneous time recording of ambient temperature and humidity.

A nephoscope in which the motion of the cloud is observed by its reflection in a mirror.

Quantitative Precipitation Forecast.

A counterclockwise change in wind direction. Backing winds with height are indicative of cold air advection (CAA).

check chamber-A chamber use to check the sensing elements of radiosonde equipment.

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.

Abbreviation for the pressure, temperature, and humidity data obtained by a radiosonde observation.

The quantity to be measured (or modulated, or detected, or operated upon) which is received by an instrument. Thus, for a thermometer. temperature is the input quantity.