Abstract: An expert system for synoptic climatology. The expert system comprises a user interface that interacts with a user to obtain geographical information. An inference engine executes expert rules based on the geographical information. A synoptic climatology knowledge base provides the inference engine with the expert rules. A method for representing geographical information related to synoptic climatology for use in the expert system. The method comprises partitioning the world into climatic regions. The climatic regions are partitioned into subregions. The subregions are partitioned into zones of climatic commonalty. The climatic regions, subregions and zones of climatic commonalty are put into a frame hierarchy.