Wind with a speed between 17 and 21 knots (19 and 24 mph); Beaufort scale number 5.

The outer, solid portion of the earth: the crust of the earth.

A strong wind characterized by a sudden onset, a duration on the order of minutes, and a rather sudden decrease in speed.

Same as atmometer.

A clay atmometer consisting of a hollow ceramic sphere through which evaporation occurs. Evaporation is measured by the loss of water from the reservoir which feeds the sphere.

A hygrometer based upon the diffusion of water vapor through a porous membrane.

A type of atmometer. It is a pan used in the measurement of the evaporation of water into the atmosphere. The NWS Class A pan is a cylindrical container 48 inches in diameter and 10 inches deep.

Force wind-Wind with a speed above 64 knots (73 mph); Beaufort scale numbers 12 through 17.

Rain gauge which registers precipitation that is too light to be registered by ordinary recording of the depth of water from precipitation. Same as ombrometer.

A class of rain gauge in which the level of the collected rain water is measured by the position of a float resting on the surface of the water.

Abbreviation for radio frequency.

An elongated area of relatively high pressure. Usually associated with and most clearly identified as an area of maximum anticyclonic curvature of the wind flow. The opposite of a trough.

Precipitation of white, opaque, spherical or conical ice particles that are crisp and easily crushed and that have diameters of 2 to 5 mm.

Instrument for measuring the mean intensity of glo global solar radiation (direct and diffuse) near the earth's surface in a specified time interval.

One of several constant-pressure levels in the atmosphere for which a complete evaluation of data derived from upper air observations is required.

The transducer of any hygrometer, i.e. that part of a hygrometer that quantitatively "senses" atmospheric water vapor.

The value of the quantity measured, as indicated or otherwise provided by a measuring instrument.

Apparatus designed to measure and record the size distribution of raindrops as they occur in the atmosphere.

A type of wind vane having a split or V-shaped tail. The apex orients itself to the direction of the wind.

A c.g.s. (centimeter-gram-second) unit of mass. Originally defined as the mass of 1 cubic centimeter of water at 4