The unit of force in the centimeter-gram-second system of physical units, i.e. one gm cm per sec2, equal to 7.233 x 10-5 poundal.

The ratio of the output of an instrument to the input value, i.e. a rain gauge with a sensitivity of 1 tip per 0.01"

Wind with a speed between 22 and 27 knots (25 and 31 mph); Beaufort scale number 6.

Anemometer which measures wind speed by the speed of rotation of 3 or 4 hemispherical or conical cups, each fixed to the end of a horizontal arm projecting from a vertical axis. See condenser-discharge anemometer, contact anemometer. Compare to bridled-cu ...

A precipitation amount of less than 0.005 inches. Also, the record made by any self-registering instrument.

The rate of decrease of pressure per unit distance at a fixed time.

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. ...

Thermometer used for measuring the highest temperature attained during a given interval of time, for example, a day.

Forecasting weather by the use of numerical models, run on high speed computers. Most of the NWP for the National Weather Service is done at the National Centers for Environmental Prediction (NCEP).

Precipitation composed of balls or irregular lumps of ice with diameters between 5 and 50 mm.

The inaccuracy that the manufacturer permits when the unit is calibrated in the factory.

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

A systematic observational error due to the characteristics of the observer. The uncertainty in a reading made by an observer may be acertained by a statistical analysis of his or her readings.

That portion of the record of a microbarograph between any two (or a specified small number) of successive crossings of the average pressure level (in the same direction). Analogous to microseism.

An instrument consisting of a series of graduated cylinders possessing selective collection efficiencies. It is used for the measurement of quantities relating to the size distribution of cloud droplets.

A device that allows a terminal or computer at one location to communicate with a terminal or computer at a distant location via wire or phone lines.

A type of disk hardness-gauge, especially useful in relatively soft snow. See disk hardness gauge.

A device that combines several separate communications signals into one and outputs them on a single line.

A standard interface between a computer input/output port and a peripheral device. Signal properties including time duration, voltage. and current, are specified by the Electronic Industries Association.

The portion of the strearnflow during any month or year derived from precipitation in previous months or years.