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.

A type of precipitation composed of unbranched crystals in the form of needles, columns, or plates. Usually has a very slight downward motion and may fall from a cloudless sky.

A subtle, diumal component of the wind velocity leading to a diumal shift of the wind or turning of the wind with the sun, produced bv the east-to-west progression of daytime surface heating.

A unit of energy equal to 101 ergs or to 0.2389 calories.

See bimetallic thermometer.

An instrument which indicates the presence of precipitation. The ombroscope consists of a heated, water-sensitive surface which indicates by mechanical or electrical techniques the occurrence of precipitation.

A thermometer. the sensitive element of which consists of two metal strips which have different coefficients of expansion and are brazed together. The distortions of the system in response to temperature variations are used as a measure of temperature. It ...

The outer, solid portion of the earth: the crust of the earth.

The water volume within a specified portion of a stream channel.

Integrated Flood Observing and Warning System. National Weather Service flood warning program.

A type of pressure-plate anemometer in which the plate, restrained by a stiff spring, is held perpendicular to the wind. The wind-activated motion of the plate is measured electrically. The natural frequency of this system can be made high enough so that ...

Any soft, gentle breeze.

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

An instrument for recording global solar radiation.

See wind vane.

A box-like structure designed to protect certain meteorological instruments from exposure to direct sunlight, precipitation, and condensation, while at the same time providing adequate ventilation. Instrument shelters are painted white, have louvered side ...

An evaluation of upper air temperature, pressure, and humidity from radio signals received from a balloon- borne radiosonde.

A continuous-recording barometer.

The level at which ice crystals and snowflakes melt as they descend through the atmosphere.

An instrument for taking photographs of an image of the sun in monochromatic light.