The minimum temperature shown by a minimum thermometer exposed in an open situation with its bulb at the level of the tops of the grass blades of short turf.

A refraction phenomenon similar to a parahelion, but occurring generally at a distance of 120

Same as dropsonde.

The process by which small particles suspended in a medium of a different refractive index diffuse a portion of the incident radiation in all directions. In scattering no energy transformation results, only a change in the spatial distribution of the radi ...

Occupational Safety and Health Administration. A regulatory office of the U.S. Department of Labor.

Routine broadcast of meteorological information for aircraft in flight.

The state of the atmosphere, mainly with respect to its effects upon life and human activities. As distinguished from climate, weather consists of the short-term (minutes to months) variations of the atmosphere.

An instrument for the measurement of the rate of ice accretion on an unheated body.

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

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

Facing away from the wind.

See standard atmosphere.

The lowest level at which the wind becomes geostrophic in the theory of the Ekman spiral. Also called gradient wind level.

(1) The ratio of the speeds of a chemical reaction at two temperatures differing by 10

An instrument that shows changes in humidity.

A cylinder installed in a body of water or an evaporation pan to hold a sensor, such as a float to measure water level or a hook gage. The stillwell is constructed so that there is free movement of water in and out of it, and it therefore provides a repre ...

The total infrared radiation emitted from the earth's surface. To be carefully distinguished from atmospheric radiation, effective terrestrial radiation, and insolation.

The upper surface of a column of liquid.

The transmission of data collected at a remote location over communications channels to a central station.

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