High winds generated by bow echoes. Part I: Overview of the Omaha bow echo 5 July 2003 storm during BAMEX

Part I of this study presents a combination of airborne Doppler-derived wind syntheses with a comprehensive damage survey in order to document the generation of strong winds at the surface. A detailed kinematic analysis of the evolution of a quasi-linear convective system into a bow-shaped and, subsequently, a spearhead echo is shown for the first time.

It is hypothesized that a large, cyclonic bookend vortex (70-80 km in diameter) north of the bow apex enhanced the rear-inflow jet and initiated the bowing process. A hook-shaped echo and mesovortex formed at the apex of a bowed segment of the convective line and was located to the north of the swath of strong damage rated greater than F1 in damage intensity. The peak single-Doppler radial velocity recorded by the tail radar was 43 m s(-1) in the low-level outflow near the apex of the bow echo.