Situated on the side from which the wind blows.

A vector term which includes both wind speed and wind direction.

A rainbow formed by light rays which have been reflected from an extended water surface. Not to be confused with a reflected rainbow whose image may be seen in a still body of water. The center of a reflection rainbow is at the same elevation as the sun b ...

An Instrument used to determine dew point.

The direction, with respect to true north, from which the wind is blowing. Distinguish from magnetic wind direction. In all standard upper-air and surface weather observations, it is true wind direction that is reported.

A hygrometer in which the sensitive element is a strand or strands of human hair, the length of which is a function of the relative humidity of the air.

A unit of energy defined as the heat required to raise the temperature of one pound of water one degree Fahrenheit. It is equal to 252.1 calories or to 1055 joules.

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.

An instrument for measuring radiant energy. See actinometer, Dines radiometer, photometer, Tulipian radiometer.

The change in barometric pressure within a specified period of time (typically 3 hours for meteorological observations).

An instrument that shows changes in humidity.

Water condensed onto objects at or near the ground, due to the fact that their temperatures have fallen below the dew point temperature of the surrounding air, but not below freezing.

A rocket designed primarily for routine upper air observations in the lower 250,000 feet of the atmosphere, especially that portion inaccessible to balloons (above 100,000 feet).

A general term for instruments which sample atmospheric suspensoids by impaction. Same as impactometer.

The humidity transducinu element in a Diamond-Hinman radiosonde. Also called electrolytic strip.

Old snow that has become granular and compacted as a result of melting and refreezing.

Tables prepared from the psychrometric formula and used to obtain vapor pressure, relative humidity, and dew point from values of wet-bulb and dry-bulb temperatures.

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

An instrument for collecting liquid water from the atmosphere.

A device for measuring the river stage. Also called stream gauge.