Sustained winds greater than or equal to 40 mph or gust greater than or equal to 58 mph.

An instrument, dropped from high attitude and carried by a stable parachute. used to measure the vertical component of turbulence aloft.

A series of Nansen-bottle water samples and associated temperature observations resulting from one release of a messenger.

Read Only Memory. A memory that cannot be altered in normal use of a computer, Usually used to store information permanently, such as firmware programs.

The maximum deviation of any points from a straight line drawn as a "best fit" through the calibration points of an instrument with a linear response curve. Usually expressed as a percentage of full- scale range.

A hygrometer which includes an arrangement for the time recording of atmospheric humidity.

Growth of a cloud or precipitation particle by the collision and union of a frozen particle with a super-cooled water drop.

An instrument used for measuring geometric angles. See radio direction-finder.

The height at which the maximum wind speed occurs, determined in a winds-aloft observation.

variable audio-modulated radiosonde developed at the Bureau of Standards and used by the United States weather services.

The part of a measuring instrument which responds directly to changes in the environment.

An instrument for recording ocean waves. Most recorders are designed for recording wind waves, that is waves of periods up to about 25 seconds, but some are designed to record waves of longer periods such as tsunamis or tides.

The value of the quantity measured, as indicated or otherwise provided by a measuring instrument.

A unit of pressure equal to 10' dyne per cm-' (101 barye), 1000 millibars. 29.53 inches of mercury.

A rotation anemometer which has a horizontal axis upon which helicoidal shaped vanes are mounted. See windmill anemometer.

An up slope wind due to local surface heating. Opposite of katabatic wind.

An instrument which records the duration of sunshine and gives a quantitative measure of the amount of sunshine by the action of the sun's rays upon blueprint paper. A type of sunshine recorder.

Same as atmospheric pressure.

The unit of speed in the nautical system; one nautical mile per hour. It is equal to 1.1508 statute miles per hour or 0.5144 meters per second.

A unit of distance equal to 5280 feet. It is sometimes referred to as a land mile.