The maximum rate at which precipitation can pass through the surface into the soil, for a given soil in a given condition.

See ceilometer.

The difference between the input quantity applied to a measuring instrument and the output quantity indicated by the instrument. The inaccuracy of an instrument is equal to the sum of its instrument error and its uncertainty.

Temperarure at which a liquid solidifies under any given set of conditions. It may or may not be the same as the melting point or the more rigidly defined true freezing point or (for water) ice point.

The temperature registered by a thermometer with its bulb at the level of the tops of the grass blades in short turf.

A modification of the dew cell used in radiosonde equipment.

Movernent of water through the soil surface into the soil, or the quantity of water entering the soil. Infiltration is equal to the total precipitation less the losses due to interception by vegetation. retention in depressions on the land surface, evapor ...

The total area drained by a river and its tributaries. Same as watershed.

Wind with a speed between 56 and 63 knots (64 and 72 mph); Beaufort scale number 11.

A wind (or component thereof) directed down the slope of an incline and caused by greater air density near the slope than at the same levels some distance horizontally from the slope. Also called drainage wind and sometimes called katabatic wind.

Negative Vorticity Advection.

A hydrometeor consisting of a visible aggregate of minute water droplets suspended in the atmosphere near the earth's surface. Fog differs from cloud only in that the base of fog is at the earth's surface while clouds are above the surface.

The succession of stages through which water passes on the ground and in the atmosphere: evaporation from land or bodies of water, condensation to form clouds, precipitation, accumulation in the soil or in bodies of water, and re-evaporation.

Same as fogbow.

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

A form of psychrometer with wet-bulb and dry-bulb thermometers mounted on opposite sides of a specialty designed graph of the psychrometric tables. It is so arranged that the intersections of two curves determined by the wet-bulb and dry-bulb readings -yi ...

An Instrument used to determine dew point.

See hook gauge.

The elevation of the water surface in a stream as measured by a river gauge with reference to some arbitrarily selected zero datum.

A nephoscope in which the motion of the cloud is observed by its reflection in a mirror.