The value of the quantity measured, as indicated or otherwise provided by a measuring instrument.

An addition to a rawinsonde system which allows determination of the slant range to the radiosonde.

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

The size of the area comprising a watershed or river basin. Also called catchment area.

A water-temperature thermometer provided with an insulated container around the bulb. It is lowered into the sea on a line until it has had time to reach the temperature of the surface water, then withdrawn and read. The insulated water surrounding the bu ...

A modification of the dew cell used in radiosonde equipment.

Same as Aeolian.

A mercury barometer in which the lower mercury surface is larger in area than the upper surface. The basic construction of a cistern barometer is as follows: A glass tube one meter in length, sealed at one end is filled with mercury, and then inverted. Th ...

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

A rainbow formed by light rays which have been reflected from an extended water surface. Not to be confused with a reflected rainbow whose image may be seen in a still body of water. The center of a reflection rainbow is at the same elevation as the sun b ...

Same as pitot tube.

Balance of the water resources of a region, comparing precipitation and inflow with outflow, evaporation, and accumulation.

An approximation to the complete equations describing atmospheric motion in which only the terms most important for the growth and decay of synoptic scale extratropical weather systems (i.e., the large areas of high and low pressure seen on weather maps) ...

General term for any device that measures precipitation: principally a rain gauge or snow gauge.

Automated Weather Observing Station. A self-contained weather station designed to make aviation weather observations without operator involvement.

Wind with a speed between 17 and 21 knots (19 and 24 mph); Beaufort scale number 5.

Liquid water at temperatures colder than freezing.

The ratio of the actual amount of water evaporated into the atmosphere to the evaporative power. Also called relative evaporation.

Snow gauge composed of a metal cylinder, closed at one end, used to obtain a sample of snow from which the water is measured after melting.

A contact anemometer connected to an electrical circuit which is so arranged that the average wind speed is indicated.