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.

A strong wind characterized by a sudden onset, a duration on the order of minutes, and a rather sudden decrease in speed.

The meteorological visual range, which can be estimated from the average extinction coefficient using the Koschmieder equation.

A c.g.s. (centimeter-gram-second) unit of mass. Originally defined as the mass of 1 cubic centimeter of water at 4

Force wind-Wind with a speed above 64 knots (73 mph); Beaufort scale numbers 12 through 17.

A hygrometer based upon the diffusion of water vapor through a porous membrane.

Name sometimes used in place of pyranometer as a generic term.

A clay atmometer consisting of a hollow ceramic sphere through which evaporation occurs. Evaporation is measured by the loss of water from the reservoir which feeds the sphere.

Rain gauge which registers precipitation that is too light to be registered by ordinary recording of the depth of water from precipitation. Same as ombrometer.

A mercury barometer of the fixed cistern type in which a moveable scale terminating in an ivory point is used to compensate for the variations in the height of the mercury in the cistern

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

The quantity to be measured (or modulated, or detected, or operated upon) which is received by an instrument. Thus, for a thermometer. temperature is the input quantity.

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

Instrument for measuring the mean intensity of glo global solar radiation (direct and diffuse) near the earth's surface in a specified time interval.

Abbreviation for radio frequency.

An evaporation pan in which the evaporation is measured from water in a pan floating in a larger body of water.

A set of weekly colored rainbow arcs sometimes discernable inside a primary rainbow.

The process by which water in plants is transferred as water vapor to the atmosphere. Also, the amount of water so transferred.

Precipitation of white, opaque, spherical or conical ice particles that are crisp and easily crushed and that have diameters of 2 to 5 mm.

The transducer of any hygrometer, i.e. that part of a hygrometer that quantitatively "senses" atmospheric water vapor.