Random Access Memory. The memory of a computer which can be read and written into at any location without passing through preceding locations.

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 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.

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

Same as dropsonde.

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

Routine broadcast of meteorological information for aircraft in flight.

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

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.

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

An apparatus, used in studying soil temperatures, for measuring the total supply of heat during a given period.

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

An instrument that shows changes in humidity.

See standard atmosphere.

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

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

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

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

A temperature-sensing element which converts thermal energy directly into electrical energy. In its basic form it consists of two dissimilar metallic conductors connected in a closed loop. Each junction forms a thermocouple. If one thermocouple is maintai ...

The visibility along an identified runway, determined from a specified point on the runway with the observer facing in the same direction as a pilot using the runway. Compare to runway visible range.