The traditional meteorological charts used by forecast services for synoptic analysis and forecast has seldom changed over the years, while our understanding of the atmosphere has improved thanks to satellite images, in parallel with the progress in dynamic meteorology and numerical simulation. Such presentation of the synoptic situation does not emphasize the importance of upper level forcings, nor reflect the wealth of atmospheric structures. Nowadays, modern dynamic meteorology provides us with a firm framework to build a more complete graphical summary of the synoptic atmosphere than the polar front concept. Moreover, the present guidance prepared at the central forecast office (surface maps and long texts) is not efficient enough to convey the synoptic expertise towards the weather offices. This is the reason why Météo-France decided to introduce a new graphical product named ANASYG-PRESYG (standing for Graphical SYnoptic ANAlysis or PREdiction) allowing to summarize as best as possible all the relevant meteorological information at the synoptic scale.

The ANASYG-PRESYG is a two-level symbolic representation of the synoptic situation. It includes the crucial upper-level dynamic elements superimposed on the surface phenomena and the mean sea-level pressure. Upper-level jets and tropopause anomalies (diagnosed at the dynamic tropopause which is defined as the 1.5 Pv surface) plotted with symbols allow to mark the upper troposphere dynamics. An extended set of symbols is available to represent the various kinds of fronts and other surface discontinuities as well as the activity of weather systems.

This new form of the synoptic guidance compelled Météo-France to undertake a large training action towards forecasters. A Computed Aided Learning (CAL) software has been built (in French and English versions) for this purpose. In addition to a theoretical part dedicated to the bases of dynamic meteorology, this CAL includes an important practical part explaining the various conceptual models of mid-latitude phenomena and their appropriate associated symbols. Concrete examples illustrate these conceptual models and show how to identify them by means of model fields, observations and satellite images : each forecaster must have in mind the same phenomenon through a given conceptual model, and each conceptual model has to be represented by an accurate symbol that must be defined without ambiguity. This CAL allows manipulations and practical work near the forecaster's workplace with help of workstation facilities (animation, superimposition, interactive exercises…). Finally, it can be a permanent guide available on forecaster's workstation. Some representative examples of the modules that make up this CAL will be presented to illustrate the efficiency of such a tool for the wide-spreading training action going to take place in the Météo-France forecasting services.