A severe weather condition characterized by low temperatures and strong winds bearing a great amount of snow, either falling or picked up from the ground.

An instrument for measuring the frost point of the atmosphere.

A thermometer, invented by James Six in 1782, which simultaneously indicates the maximum and minimum temperatures attained during a given interval of time. A U-tube min/max thermometer

A method of winds aloft observation essentially the same as a pilot balloon observation except the height data is derived from the radiosonde observation rather than from assumed ascension rates.

A photometer which measures the intensity of radiation as a function of the frequency (or wavelength) of the radiation.

Same as wave pole.

A fixed support for mounting maximum and minimum thermometers of the liquid-in-glass type. The support holds the thermometers at the correct operating attitude and also permits their rotation for resetting when desired.

A component of a radiosonde consisting of a series of alternate electrically conducting and insulating strips. As these are scanned by a contact the radiosonde transmits temperature and humidity signals alternately. The contact may be a baroswitch as in t ...

An early and once universal name for the mercury barometer.

For a given location, a measure of the long-range effectiveness of precipitation in promoting plant growth. Also called precipitation-evaporation index.

Navy Operational Global Atmospheric Prediction System. A global meteorological model operated by the Department of Defense.

A surface weather observation, made at periodic times, of sky cover, state of the sky, cloud height, atmospheric pressure reduced to sea level, temperature, dew point, wind speed and direction. amount of precipitation, hydrometeors and lithometeors. and s ...

The ratios, to the mean wind speed, of the average magnitudes of the component fluctuations of the wind along three mutually perpendicular axes.

An instrument used for the determination of the electrical conductivity of the atmosphere.

A rain gauge which indicates but does not record the amount of precipitation captured.

Situated on the side from which the wind blows.

A type of cloud height indicator which uses a searchlight to project vertically a narrow beam of light onto the cloud base. The height of the cloud is determined using a clinometer, located at a known distance from the ceiling light, to measure the angle ...

The component of the radiosonde which includes the modulating blocking oscillator and the radiofrequency carrier oscillator.

Sir Napier Shaw's name for the approximate absolute temperature scale,

In a system of moist air, the dimensionless ratio of the mass of water vapor to the total mass of the system.