An instrument which measures the instantaneous rate at which rain is falling on a given surface. Also called a rate-of-rainfall gauge.

Snow shower, particularly of a very light and brief nature.

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 semiconductor which exhibits rapid and extremely large changes in resistance for relatively small changes in temperature.

The depth below which the ground is saturated with water. No water table exists if the ground water is confined by an overlying impermeable stratum, as in the case of artesian ground water.

Quantitative Precipitation Forecast.

bucket rain gauge-A rain gauge where the precipitation collected by the receiver empties into one side of a chamber which is partioned transversely at its center and is balanced bistably upon a horizontal axis. When a predetermined amount of water has bee ...

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

An instrument for measuring snow hardness in terms of the resistance of snow to the pressure exerted by a disk attached to a spring-loaded rod, a gauge calibrated in pounds per square inch registers the amount of resistance. See Canadian hardness gauge.

The scientific study of the waters of the earth, especially with relation to the effects of precipitation and evaporation upon the occurrence and character of water in streams, lakes, and on or below the land surface. In terms of the hydrologic cycle, the ...

A psychrometer in which the ventilation is provided by a suction fan.

A mercury-in-glass thermometer which records the temperature upon being inverted and retains its reading until being returned to the first position.

See bimetallic thermometer.

That part of an audio-modulated radiosonde consisting of the baroswitch, the sensing elements, the reference elements, and the relay.

A cone-tipped metal rod designed to be driven downward into deposited snow or firn. The measured amount of force required to drive the rod a given distance is an indication of the physical properties of the snow or firn.

In general, the transformation of data from a "raw" form to some useable form. In meteorology, this often refers to the conversion of the observed value of an element to the value which it would theoretically have at some selected or standard level. The m ...

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 ...

Any and all forms of water particles, liquid or solid, that fall from the atmosphere and reach the ground.

A unit of distance equal to 5280 feet. It is sometimes referred to as a land mile.

Electromagnetic radiation lying within the wavelength interval to which the human eye is sensitive, the spectral interval from approximately 0.4 to 0.7 microns (4000 to 7000 angstroms). Bounded on the short-wavelength end by ultraviolet radiation and on t ...