Analysis of the severe Mid-Atlantic Derecho of 04 June 2008
Zubrick, Steven M; Schoor, Gregory M; Eckert, Michael

During the afternoon of Wednesday 04 June 2008, a severe derecho moved out of the Ohio Valley and raced across the Mid-Atlantic states. The storm produced numerous reports (~125) of wind damage along its roughly 800 km overland track that stretched from the Ohio Valley (southern Ohio) to the Mid-Atlantic coast (Maryland/Delaware), spanning 5 states, and continued moving across the western Atlantic Ocean. The derecho spawned nearly a half dozen weak, short-lived tornadoes (EF0 or EF1) across northern Virginia and north-central Maryland. The derecho moved along and south of a weak stalled front boundary that extended from central Ohio eastward to the Delaware Bay area. The line of severe storms prompted numerous severe thunderstorms warnings from Ohio eastward to Delware. Unofficial wind gust measurements of 85 mph upwards to nearly 100 mph were recorded in portions of the eastern West Virginia panhandle. This presentation will provide a brief overview of the meteorological conditions that favored conditions for long-track storms. Then an overview of the radar structure of the quasi-linear derecho will be provided. Radar data of the embedded and leading-edge circulations that produced tornadoes will be shown. The challenges forecasters faced in provided appropriate warnings will be discussed.