Of or pertaining to rain.

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.

A rain gauge capable of measuring very small amounts of precipitation. Also called micropluviometer, trace recorder.

Wind with a speed between 11 and 16 knots (13 and 18 mph); Beaufort scale number 4.

Pertaining to rain, or more broadly, to precipitation.

Same as balloon cover.

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.

The ratio of the existing amount of water vapor in the air at a given temperature to the maximum amount that could exist at that temperature. Usually expressed in percent.

The rising of cold water from the deeper areas of the ocean to the surface. This phenomena often occurs along the California coast during the spring and summer.

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"

A clock-driven instrument mounting which automatically and continuously points in the direction of the sun. It is used with a pyrheliometera,hen continuous direct solar radiation measurements are required.

A description or explanation of the manner in which the height of the ceiling is determined, i.e. aircraft ceiling, balloon ceiling. estimated ceiling, indefinite ceiling, measured ceiling, precipitation ceiling.

A number of quantity defining a limit that errors will not exceed when a device is used under specified operating conditions. Accuracy rating can be expressed in a number of forms, i.e. in terms of the measured variable (+/- 1 C), percent of span (+/-0.5% ...

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

An instrument used for measuring geometric angles. See radio direction-finder.

See evaporative opportunity.

A common type of liquid-inglass thermometer, used, in meteorology, in psychrometers and as a maximum thermometer.

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

A vent used with pressure sensors to reduce the effect of wind on the pressure inlet. It is normally mounted remotely and connected to the sensor using airtight tubing.

The lowest level at which the wind becomes geostrophic in the theory of the Ekman spiral. Also called gradient wind level.