Quantitative Precipitation Forecast.

A unit of energy equal to 101 ergs or to 0.2389 calories.

A numbering system using a base number of 16 and including the ten decimal digits (0 to 9) along with six alpha digits (A to F). Thus. a digit is available to represent each of the possible values of a 4-bit binary digit.

A method of winds aloft observation essentially the same as a pilot balloon observation except the height data is derived from the radiosonde observation rather than from assumed ascension rates.

A unit of pressure equal to 10' dyne per cm-' (101 barye), 1000 millibars. 29.53 inches of mercury.

The standard deviation of a sufficiently large number of measurements of the same quantity by the same instrument or method. The non-correctable part of the inaccuracy of an instrument, it represents the limit of measurement precision. The uncertainty of ...

The process by which water in plants is transferred as water vapor to the atmosphere. Also, the amount of water so transferred.

A basic equation in daytime visual range theory, relating the apparent luminance of a distant black object, the apparent luminance of the background sky above the horizon, and the extinction coefficient of the atmosphere, or the air layer near the ground. ...

A sounding balloon which, when operationally inflated, resembles an inverted teardrop.

The meteorological visual range, which can be estimated from the average extinction coefficient using the Koschmieder equation.

Name given to the unit of pressure in the International System of Units (SI). Equal to 1 newton/meter2 or 0.01 millibar.

Based upon damage patterns, classifies twisters into six categories of wind speed (F0 thru F5), ranging from 40 to 318 mph estimated wind speed.

See hurricane beacon.

A type of modulation in which the frequency of a continuous radio carrier wave is varied in accordance with the properties of a second (modulating) wave.

Operation mode of a communication circuit in which each end can simultaneously transmit and receive.

See Koschmieder's law.

A description or explanation of the manner in which the height of the ceiling is determined, i.e. aircraft ceiling, balloon ceiling. estimated ceiling, indefinite ceiling, measured ceiling, precipitation ceiling.

An instrument, for the recording of two or more meteorological parameters, in which the ventilation is provided by a suction fan.

Generally, an instrument designed to measure or estimate the blueness of the sky. See Linke-scale.

An instrument used for measuring geometric angles. See radio direction-finder.