Cold Fronts Research: The Australian Summertime “Cool Change”

Abstract

Much of the significant weather of southeastern Australia is associated with the passage of cold fronts. In summer, such passages are often accompanied by rapid and extreme temperature fails, as hot continental northerly winds are replaced with much colder south-westerlies from the Southern Ocean; for this reason, they are popularly and aptly known as ?cool changes.? These summertime fronts, which normally form part of a front-trough complex sandwiched between two anticyclones, are ill-understood and lead to many forecasting problems. In early 1979, a Cold Fronts Research Programme was established as a coordinated long-term project to study front-trough systems affecting this region of Australia. The program, which involves all of the major Australian meteorological centers, has been designed to include three observational phases over five years, with emphasis being placed on summertime frontal systems. Each phase of intensive observations is of four weeks duration, and Phases I and II have now been completed. This article summarizes the philosophy behind the program, outlines its scientific objectives, and describes the observational networks employed. A brief review of the results of Phases I and II and an outline of future activities also is presented.