Synoptic Frontal Analysis: Time for a Reassessment?

Abstract

For over a half-century, the Bergen School conceptual model of cyclone structure and development has dominated the practice of synoptic meteorology, especially regarding the techniques by which surface synoptic charts are analyzed. Although the Norwegian paradigm captures some of the essential features of cyclone evolution, research and practical application over the last 60-odd years have revealed significant deficiencies, several of which are discussed in this paper. The Bergen model has also been applied in regions and under conditions quite unlike those for which the model was originally developed. Knowledge of these problems by many in the research and operational communities has had little impact on the manner in which synoptic charts are analyzed or the way the subject is described in many textbooks. Deficiencies In the underlying conceptual model of cyclone development have been compounded by a lack of consistent and well-defined procedures for defining fronts and for analyzing surface synoptic charts. Several examples of confusing and inconsistent surface analyses are presented in this paper. To resolve these problem, the meteorological community should follow a two-pronged approach. First, the research and operational insights gained over the last half-century should be combined with recent numerical modeling and observational studies to establish improved conceptual models of cyclone evolution. Second, a clear and consistent methodology for analyzing synoptic charts should be devised. Several possible approaches for implementing these suggestions are presented in this paper.