An instrument for measuring the frost point of the atmosphere.

The transducer's output when the maximum sensed value is applied to the transducer's input. For example, the F.S. output of a 4-20 mA transmitter is 20 mA, whereas its span is only 16mA.

Solar and terrestrial radiation directed downwards (towards the earth's surface); incoming radiation.

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.

Precipitation composed of liquid water drops more than 0.5 mm in diameter, failing in relatively straight, but not necessarily vertical, paths. Compare to drizzle.

A general term to designate apparatus designed to observe the details of weather during thunderstorms.

An instrument which measures the spectral distribution of the intensity of direct solar radiation.

The actual lifting force of an inflated balloon, usually expressed in grams.

See instrument error, observational error. random error, standard error, systematic error.

A synoptic code approved by the World Meteorological Organization in which the observable meteorological elements are encoded and transmitted in "words" of five numerical digits length. Often abbreviated synoptic code.

A type of directional antenna used on some types of radar and radio equipment consisting of an array of elemental, single- wire dipole antennas and reflectors.

Apparatus consisting of (a) standard radiosonde and radiosonde ground equipment to obtain upper-air data on pressure, temperature, and humidity, and (b) a self-tracking radio direction-finder to provide the elevation and azimuth angles of the radiosonde s ...

General term for an instrument used to make direct measurements of visual range or measurements of the physical characteristics of the atmosphere which determine the visible range.

See mote.

A type of climatic diagram whose coordinates are some form of temperature vs. a form of humidity or precipitation.

An aviation weather forecast for a specific flight.

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

See calorie.

Wind with a speed between 7 and 10 knots (8 and 12 mph), Beaufort scale number 3.

A seasonal wind of persistent direction, characterized by a pronounced change in direction between seasons.