A conically shaped, copper rain gauge shield.

The total area drained by a river and its tributaries. Same as watershed.

A basic equation in daytime visual range theory, relating the apparent luminance of a distant black object, the apparent luminance of the background sky above the horizon, and the extinction coefficient of the atmosphere, or the air layer near the ground. ...

A small pointer extending downward from the top of the cistern of a Fortin barometer. The level of the mercury in the cistern is adjusted so that it just comes in contact with the end of the pointer, thus setting the zero of the barometric scale.

A temperature scale based on absolute zero. Same as Kelvin temperature scale.

See radiation shield.

See gust and peak gust.

An instrument which automatically records the measurement of two or more meteorological elements.

Same as fogbow.

An aneroid barometer arranged so that the deflection of the aneroid capsule actuates a pen which graphs a record on a rotating drum. Sometimes called aneroidograph.

Ragged low clouds, usually stratus fractus. Most often applied when such clouds are moving rapidly beneath a layer of nimbostratus.

A system of estimating and reporting wind speed, originally based on the effect of various wind speeds on the amount of canvas that a full-rigged nineteenth century frigate could carry.

In meteorology, a deflecting force acting on a body in motion and resulting from the earth's rotation. It deflects air currents to the right in the northern hemisphere and to the left in the southern hemisphere, thus having an effect on wind direction.

A class of rain gauge in which the level of the collected rain water is measured by the position of a float resting on the surface of the water.

A type of climatic diagram whose coordinates are some form of temperature vs. a form of humidity or precipitation.

An anemometer in which the sensor rotation is transmitted to a mechanical counter which directly integrates the air movement past the sensor. Used to determine total air passage (wind run). Average wind speed can be calculated from the difference between ...

Dihydrogen oxide, molecular formula H2O.

The volume of water required to cover one acre to a depth of one foot: 43,560 cubic feet.

Wind with a speed between 34 and 40 knots (39 and 46 mph); Beaufort scale number 8.

The process by which small particles suspended in a medium of a different refractive index diffuse a portion of the incident radiation in all directions. In scattering no energy transformation results, only a change in the spatial distribution of the radi ...