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

Wind with a speed between 34 and 40 knots (39 and 46 mph); Beaufort scale number 8.

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 spring which is designed to achieve a fixed spring constant over a wide temperature range. Usually, this involves an alloy with high nickel content such as Ni-Span C. It is common for these springs to be stress relieved at elevated temperature after for ...

A unit that represents one degree of deviation from a reference point in the mean daily outdoor temperature (usually 65

Barometer in which pressure is determined by balancing air pressure against the weight of a column of mercury in an evacuated glass tube.

A graduated scale placed in a position so that the stage of a stream may be read directly from it. Staff gauges may be placed on bridge piers or pilings, etc., or placed on specially constructed supports.

Wind with a speed between 28 and 55 knots (32 and 63 mph); Beaufort scale numbers 7 through 10.

Any one of a family of circular arcs consisting of concentric colored bands, arranged from red on the inside to blue on the outside, which may be seen on a "sheet" of water drops (rain, fog, spray). The most common of the many possible is the primary rain ...

A numbering system using a base number of 16 and including the ten decimal digits (0 to 9) along with six alpha digits (A to F). Thus. a digit is available to represent each of the possible values of a 4-bit binary digit.

The writing component of a recording instrument.

A plastic molding component formed by the reaction of phenol and formaldehyde. It can be heavily reinforced or "filled" with glass fibers or other materials. Phenolics are known for their high impact strength, excellent wear characteristics, and dimension ...

Any meteorological instrument, such as a radiosonde, in which the recording apparatus is located at some distance from the measuring apparatus.

Ice crystal deposits formed by sublimation (conversion of water vapor directly to ice) when temperature and dew point are below freezing.

A coating of ice, generally clear and smooth. formed by the freezing of supercooled water on a surface.

A measure of the amount of "spin" (or rotation) in the atmosphere.

The length of air flow past a wind vane required for the vane to respond to 50 percent of a step change in wind direction. Expressed in feet or meters and calculated from delay time times wind tunnel speed.

An instrument which records the duration of sunshine and gives a quantitative measure of the amount of sunshine by the action of the sun's rays upon blueprint paper. A type of sunshine recorder.

A seasonal wind of persistent direction, characterized by a pronounced change in direction between seasons.

(1) The ratio of the speeds of a chemical reaction at two temperatures differing by 10