An instrument for measuring the extinction coefficient in water.

A device used on certain types of instruments to prevent unwanted radiation from affecting the measurement of a quantity. Also called solar radiation shield.

Apparatus designed to measure and record the size distribution of raindrops as they occur in the atmosphere.

An absolute pyhrliometer, developed by C.G. Abbott, in which the radiation-sensing element is a blackened water-calorimeter.

A set of electrical conductors, often on a backplane, that carry data and power signals among the various components of a computer.

NEXt Generation RADar. A NWS network of about 140 Doppler radars operating nationwide.

Wind with a speed between 56 and 63 knots (64 and 72 mph); Beaufort scale number 11.

A type of atmometer. It is a pan used in the measurement of the evaporation of water into the atmosphere. The NWS Class A pan is a cylindrical container 48 inches in diameter and 10 inches deep.

The upper surface of a column of liquid.

Any device or instrument for measuring salinity, especially one based on electrical conductivity methods.

That temperature at which, in a specified latitude, the reading of a particular barometer requires no temperature or latitude correction.

Anemometer whicb measures wind speed by measuring the degree of cooling of a metal wire heated by an electric current. A type of cooling power anemometer.

A coating of ice, generally clear and smooth. formed by the freezing of supercooled water on a surface.

A system of physical units based on the use of the centimeter, gram. and the second as elementary quantities of length. mass. and time.

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

Reduction of visibility by strong winds blowing across dry ground with little or no vegetation. Visibilities of 1/8 mile or less over a widespread area are criteria for a Blowing Dust Advisory.

The indicating part of an instrument. For example, the hand of a watch or the meniscus of a mercury column.

Amount of water, expressed as a depth or as a mass, which would be obtained if all the water vapor in a specified column of the atmosphere were condensed and precipitated.

United Kingdom forecast model. (Available via AccuWeather.com Professional.)

The height ascribed to the lowest layer of clouds or obscuring phenomena when it is reported as broken, overcast, or obscuration and not classified as "thin" or "partial." The ceiling is termed unlimited when these conditions are not satisfied. ...