Any soft, gentle breeze.

Operation mode of a communication circuit in which each end can transmit and receive, but not simultaneously.

Wind with a speed between 4 and 6 knots (4 and 7 mph), Beaufort scale number 2.

A fixed support for mounting maximum and minimum thermometers of the liquid-in-glass type. The support holds the thermometers at the correct operating attitude and also permits their rotation for resetting when desired.

Precipitation falling from a cloud, usually in wisps or streaks, but evaporating before it reaches the ground.

See stage.

An instrument which automatically records the voltage applied to it, as a function of time.

Instrument which measures and records the amount of evaporation over time.

A photometric unit of illuminance or illumination equal to one lumen per square meter

A hydrostatic principle that pressure supplied to an enclosed fluid is transmitted undiminished to every portion of the fluid and to the walls of the containing vessel.

An effect noted primarily in wet snow conditions when snow clings to the sides of a precipitation gauge and gradually accumulates until the gauge orifice is capped with accumulated snow. This effect can be minimized by using large collectors, and wind scr ...

Temperature of equilibrium between the liquid and vapor phases of a substance at a given pressure.

An automatic, recording cloud height indicator.

A halo consisting of a faint white circle passing through the Sun and running parallel to the horizon for as much as 360

The lowest value of a measured quality at which a sensor meets its accuracy specification.

The atmospheric pressure at the level of the barometer. May or may not be the same as station pressure.

A system of physical units based upon the use of the meter, the metric ton (106 grams), and the second as elementary quantities of length, mass, and time, respectively.

A liquid-in-glass thermometer which uses an organic substance such as alcohol as the thermometer liquid. This type of thermometer has a low freezing point and a high coefficient of expansion. It is less accurate, however, than a mercury thermometer.

A unit of energy equal to 1.356joules.

A record obtained from a meteorograph. A chart in which meteorological variables are plotted against time.