The mean difference between the readings of a given instrument and those of a standard instrument.

Wind with a speed between 22 and 27 knots (25 and 31 mph); Beaufort scale number 6.

Precipitation caused by the ascent of moist air over an orographic barrier such as a Mountain range.

A flower-like diagram indicating the relative frequencies of different wind directions for a given station and period of time.

Frozen or partly frozen rain.

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

A fixed-length group of bits representing the large data element handled as a unit by a computer. Word length is determined by the capacity of the CPU registers.

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

An instrument used to reveal but not necessarily measure the presence of an electrical quantity. It is used to display the output of a sensing element after suitable amplification and modification. Sometimes called display.

A scale with the ice point at zero degrees and the boiling point of water at 80 degrees, with pressure of one atmosphere.

A type of wind vane having a split or V-shaped tail. The apex orients itself to the direction of the wind.

A measure of luminous flux remaining in a light beam after it has passed through a specified distance of the atmosphere.

A unit of mass numerically equal to the molecular weight of the substance. The gram-mote or gram-molecule is the mass in grams numerically equal to the molecular weight, i.e. a gram-mole of oxygen is 32 grams.

An instrument used to indicate wind direction.

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

Electromagnetic radiation of shorter wavelength than visible radiation but longer than x-rays, between 0.02 and 0.4 micron (200 and 4000 angstrom).

The average temperature of the air as indicated by a properly exposed thermometer for a given time period, usually a day, a month, or a year.

Name sometimes used in place of pyranometer as a generic term.

Wind with a speed between 48 and 55 knots (55 and 63 mph), Beaufort scale number 10.

Determination of the total amount of snow covering a watershed or a given region. Both depth and water content of the snow may be measured, and the results may be used to predict the amount of water that will be available after melting.