Infrared radiation emitted by or being propagated through the atmosphere.

A conductor or system of conductors for radiating and/or receiving radio energy. Also called aerial.

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

An anemometer utilizing the principle that the pitch of the aeolian tones generated by air moving past an obstacle is a function of the speed of the air. Largely a curiosity and has been put to no practical application in modem meteorology.

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 ...

Overflowing by water of the normal confines of a stream or other body of water, or accumulation of water by drainage over areas which are not normally submerged.

A very sensitive electrostatic electrometer for measuring small potential differences.

A combination cup anemometer and pressure-plate anemometer, consisting of an array of cups about a vertical axis of rotation, the free rotation of which is restricted by a suitable spring arrangement.

Of equal or constant pressure, with respect to either space or time.

A type of pressure-tube anemometer, named after the inventor.

The atmospheric pressure at the level of the barometer. May or may not be the same as station pressure.

Nested Grid Model generated every 12 hours by NCEP.

A thermograph in which ventilation is provided by a suction fan.

An elongated area of relatively high pressure. Usually associated with and most clearly identified as an area of maximum anticyclonic curvature of the wind flow. The opposite of a trough.

A vent used with pressure sensors to reduce the effect of wind on the pressure inlet. It is normally mounted remotely and connected to the sensor using airtight tubing.

The mass density of a parcel of air expressed in units of mass per volume.

A thermopile used in some types of radiation instruments. See solarimeter.

Fine dust or salt particles dispersed through a portion of the atmosphere; a type of lithometer. The particles are so small they cannot be felt or seen with the naked eye. Many haze formations are caused by the presence of an abundance of condensation nuc ...

A clock-driven instrument mounting which automatically and continuously points in the direction of the sun. It is used with a pyrheliometera,hen continuous direct solar radiation measurements are required.

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 ...