All Aboard the Downburst Express

摘要

On June 4,2008,a widespread, destructive windstorm swept across 7 states, moving rapidly from western Indiana to the Atlantic Ocean. The swath of severe weather is shown in Figure 1; each blue circle shows the location of reported downburst winds (note also a large number of hail reports [green circles] and a few tornadoes [red triangles] mixed in). What makes this event interesting is that most of the severe weather was likely generated by several long-lived thunderstorm complexes called derechos. Derechos (pronounced day-ray-cho) were first documented in 1888. They often incur widespread, significant wind damage and multiple casualties, and they pose a serious hazard to commercial air travel.