A set of rules or conventions used to standardize data transfer between devices.

Automated Weather Observing Station. A self-contained weather station designed to make aviation weather observations without operator involvement.

A protocol similar to RS232 which makes use of differential transmission to provide high speed data transmission over significantly longer distances.

An area of low barometric pressure, with its attendant system of winds. Also called a depression or cyclone.

The sum of solar and terrestrial radiation.

Programmable Read-Only Memory. Read-only memory which can be programmed by the user using a special hardware programmer.

Upwarddirected solar radiation, reflected by the earth's surface and the atmosphere.

A general name for instruments which detect the presence of (but do not necessarily measure) small electrical charges by electrostatic means. Compare to electrometer.

Difference between the temperatures of the dry-bulb and the wet-bulb thermometers of a psychrometer.

In a system of moist air, the dimensionless ratio of the mass of water vapor to the total mass of the system.

That horizontal wind velocity at which the Coriolis acceleration exactly balances the horizontal pressure force. It is directed along contour lines or isobars.

The direction, with respect to true north, from which the wind is blowing. Distinguish from magnetic wind direction. In all standard upper-air and surface weather observations, it is true wind direction that is reported.

The algebraic difference between the upper and lower limits of the measuring range of an instrument, i.e. a thermometer with a range of -35 to 50

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

Infrared radiation emitted by or being propagated through the atmosphere.

A measure of the degree to which the weather or climate of a region is favorable to the process of evaporation. Usually considered to be the rate of evaporation. under existing atmospheric conditions, from a surface of water which is chemically pure and h ...

A colloquial term in western Australia for a squall, associated with thunder, on the northwest coast in summer.

Wind with a speed below 1 knot (1 mph); Beaufort scale number 0.

The standard deviation of a sufficiently large number of measurements of the same quantity by the same instrument or method. The non-correctable part of the inaccuracy of an instrument, it represents the limit of measurement precision. The uncertainty of ...

The ratios, to the mean wind speed, of the average magnitudes of the component fluctuations of the wind along three mutually perpendicular axes.