In the direction from which the wind is blowing.

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

Ragged low clouds, usually stratus fractus. Most often applied when such clouds are moving rapidly beneath a layer of nimbostratus.

National Weather Service. Administered by the U.S. Department of Commerce.

A momentary decrease in the speed of the wind.

A system in which radar techniques are used to determine the range, elevation, and azimuth of a radar target carried a!oft by a radiosonde, so that wind data may be obtained along with the other meteorological data.

A system of estimating and reporting wind speed, originally based on the effect of various wind speeds on the amount of canvas that a full-rigged nineteenth century frigate could carry.

For a given locality and month, an empirical expression devised for the purpose of classifying climates numerically on the basis of precipitation and evaporation.

The difference between the input quantity applied to a measuring instrument and the output quantity indicated by the instrument. The inaccuracy of an instrument is equal to the sum of its instrument error and its uncertainty.

See foehn.

A form of data transmission in which the bits of each character are sent one at a time along a single communication path. Compare to parallel data transmission.

A halo consisting of a faint white circle passing through the Sun and running parallel to the horizon for as much as 360

The ratio of the amount of electromagnetic radiation reflected by a body to the amount incipient upon it, commonly expressed as a percentage. The albedo is to be distinguished from the reflectivity, which refers to one specific wavelength.

An up slope wind due to local surface heating. Opposite of katabatic wind.

Precipitation composed of liquid water drops more than 0.5 mm in diameter, failing in relatively straight, but not necessarily vertical, paths. Compare to drizzle.

A thermopile used in some types of radiation instruments. See solarimeter.

A unit of luminance (or brightness) equal to 1/6 candles per square centimeter.

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

A definite portion of a stream channel, commonly taken between two gauging stations, but may be taken between any two specified points.

Either of two colored luminous spots that appear at points 22