A large body of air having similar horizontal temperature and moisture characteristics.

Any one of numerous devices for the measurement of either speed alone or of both direction and speed (set and drift) in flowing water.

A graphical aid used in fire weather forecasting to calculate the degree of forest-fire danger (or burning index). Commonly in the form of a circular slide rule, the firedanger meter relates numerical indices of (a) the seasonal stage of foliage, (b) the ...

A thermometer consisting of a clock mechanism the speed of which is a function of temperature.

See radiosonde commutator.

An instrument for measuring angles of inclination. Used in conjunction with a ceiling light to measure cloud height at night.

Same as contact anemometer.

A definite portion of a stream channel, commonly taken between two gauging stations, but may be taken between any two specified points.

A Sunshine recorder of the type in which the time scale is supplied by the motion of the sun. The instrument, which is pointed at the celestial pole, consists of a hemispherical mirror mounted externally on the optical axis of a camera. The lens of the ca ...

An instrument used to indicate wind direction.

A wave resulting from the action of wind on a water surface.

A form of data transmission in which the bits of each character are sent one at a time along a single communication path. Compare to parallel data transmission.

The atmospheric pressure at mean sea level either directly measured by stations at sea level or empirically determined from the station pressure and temperature by stations not at sea level. Used as a common reference for analyses of surface pressure patt ...

In folklore, a name for wind.

The decrease of an atmospheric variable with height, the variable being temperature, unless otherwise specified.

Temperature to which absolutely dry air would have to be brought in order for it to have the same density as moist air, considered at the same pressure.

National Weather Service. Administered by the U.S. Department of Commerce.

See calorie.

A general term for instruments designed to measure the amount of cloudiness.

See feed.