Bow Echoes: A Tribute to T. T. Fujita

Abstract

Bow echoes represent one of the unique and more well-known forms of severe convective organization, often being responsible for the production of long swaths of damaging surface winds and small tornadoes. They are identified by their characteristic bow shape as seen on radar reflectivity displays. Much of what is known about bow echoes originated with T. T. Fujita, whose observational insights and careful analyses two decades ago still guide research and forecasting of bow-echo phenomena today. This paper reviews Fujita's contributions to our understanding of bow echoes, and also summarizes more recent observational and numerical studies that have built on the foundation that he provided. Perhaps not surprisingly, the life cycle of bow echoes as first described by Fujita, consisting of an evolution from a symmetric line of convective cells to a comma-shaped echo with a dominant cyclonic vortex, is now recognized as one of the fundamental modes of mesoconvective evolution, for both severe and nonsevere convective systems alike.