Abbreviation for mean sea level.

A unit of energy per unit area commonly employed in radiation theory. Equal to one gram-calorie per square centimeter.

Any wind blowing down an incline. If warm, it is a foehn. If cold, it may be a fall wind or a gravity wind.

The total of direct solar radiation and diffuse sky radiation received by a unit horizontal surface. Global radiation is measured by pyranometers.

Same as river gauge.

Difference between the temperatures of the dry-bulb and the wet-bulb thermometers of a psychrometer.

An instrument, for the recording of two or more meteorological parameters, in which the ventilation is provided by a suction fan.

Instrument for measuring the intensity of radiant energy. Its principle is based on the variation of electrical resistance, with the incoming radiation, of one or both the metallic strips which the instrument comprises.

The temperature registered by a thermometer with its bulb at the level of the tops of the grass blades in short turf.

Same as constant-level balloon.

Instrument which measures and records the amount of evaporation over time.

A general term to designate apparatus designed to observe the details of weather during thunderstorms.

An instrument resulting from the combination of a thermograph and a hygrograph and furnishing, on the same chart, simultaneous time recording of ambient temperature and humidity.

The maximum distance, usually horizontally, at which a given object or light source is just visible under particular conditions of transmittance and background luminance.

A decrease in the central pressure of a pressure system. Usually applied to a low rather than to a high.

A method of streamflow routing which assumes that storage is a linear function of the weighted flow in the reach and is adaptable to a simple mathematical solution.

Sustained winds greater than or equal to 40 mph or gust greater than or equal to 58 mph.

Same as marine rainbow.

The maximum positive and negative deviation observed in testing a device under specified conditions and by a specified procedure. It is usually measured as an inaccuracy and expressed as accuracy, typically in terms of the measured variable, percent of sp ...

See hurricane beacon.