The efficient and timely movement of meteorological information is a fundamental requirement of modern meteorology. Observers record information about the environment and provide it to data processing centers so that forecast guidance products may be produced.
Countries exchange information to enhance their forecasts and to produce global forecast models.
The facility to move information quickly between centers, without regard to language, and in a format that may be processed by automated means is embodied in meteorological codes. Meteorological codes are defined by the World Meteorological Organization in WMO Manual No. 306. The codes are composed of a set of code forms and binary codes made up of groups of letters representing meteorological or other geophysical elements. Different code forms are used to represent different types of observations or products. In messages, these groups of letters are transcribed into figures indicating the value of state of the elements described.