A momentary decrease in the speed of the wind.

A system of physical units based upon the use of the meter, the metric ton (106 grams), and the second as elementary quantities of length, mass, and time, respectively.

Rate of wind movement in distance per unit time.

A conically shaped, copper rain gauge shield.

An ice coating with a consistency intermediate between glaze and rime.

The processing of the form or mode of a signal so as to make it intelligible to, or compatible with, a given device.

The programs and instructions which direct a computer.

Cathode Ray Tube. A display element, consisting of a vacuum tube and screen, used with computers.

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.

A device, similar to a potometer, for measuring transpiration, consisting of a vessel containing soil in which one or more plants are rooted and sealed so that water can escape only by transpiration from the plant.

Same as wind sock.

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

A mercury-in-glass thermometer which records the temperature upon being inverted and retains its reading until being returned to the first position.

A self-recording thermometer.

See hurricane beacon.

A cup anemometer with its shaft mechanically coupled to a magneto.

The lowest temperature that can be obtained on a wet-bulb thermometer in any given sample of air. Obtained by evaporation of water (or ice) from the muslin wick. Used in computing dew point and relative humidity.

An instrument which indicates the presence of precipitation. The ombroscope consists of a heated, water-sensitive surface which indicates by mechanical or electrical techniques the occurrence of precipitation.

A temperature scale with the ice point at 273 degrees and boiling point of water at 373 degrees. It is intended to approximate the Kelvin temperature scale with sufficient accuracy for many sciences, notably meteorology.

A graphical representation of stage or discharge at a point on a stream as a function of time.