Antecedents for the Shapiro–Keyser Cyclone Model in the Bergen School Literature

Abstract Two widely accepted conceptual models of extratropical cyclone structure and evolution exist: the Norwegian Shapiro–Keyser models. The model was developed around 1920 by Bergen School meteorologists. This has come to feature an acute angle between cold warm fronts, with reduction in area sector during corresponding formation occluded front. 1990 motivated recognition alternative frontal structures depicted simulations observations rapidly developing cyclones. features a right fronts (T-bone), weakening poleward portion front (frontal fracture), extension or rear (bent-back front), wrapping bent-back form warm-core seclusion post-cold-frontal air. Although preceded 70 years, antecedents were apparent observations, analyses, presented meteorologists, their adherents, progeny. These “lost” are collected here for first time show that meteorologists aware them, although not all survived until reintroduction into 1990. Thus, can be viewed as synthesis various elements recognized