The term "derecho" was not in my vocabulary until the evening of June 29, 2012, when the Washington, D.C. area was blasted by a storm system that had begun in Iowa that morning.

The straight-line wind on a day when storms were unexpected, was astonishing (70-80 mph around in and around DC) and few people knew it was going to happen until a couple hours before it did, if then, at 10:30 p.m. on a Friday night.

In just Virginia, DC and Maryland, over 2,000,000 power company customers were left in the dark and without air conditioning and refrigeration -- amidst a heat-wave that would continue for the next week. Many friends were without power for several days and some were trapped on their streets until fallen trees could be moved out of the way. My neighborhood was largely unscathed because our power lines are underground yet within a couple of days our nearby service stations were running out of gas because of people coming in from the 'burbs to fill up (gas stations in the affected areas also lost power).

That derecho was the most significant natural disaster, by far, since I moved here thirty years ago. And I hadn't even known what a derecho was. So it was with keen interest today that I saw reports of a derecho in Iowa and Illinois (where the 2012 derecho formed). If you're in the midwest or east coast, this is a phenomenon to be familiar with.

Report on today's derecho in the midwest:

http://www.washingtonpost.com/blogs/capi...ne-force-winds/


Below is a National Weather Service in-depth after-action report on the 2012 derecho. It is largely self-critique of their performance and recommendations for improvements. It includes a highly detailed retrospective on the formation and effect of that derecho. Interesting reading for weather-geeks (myself) and the preparedness-minded (presumably most ETS-ers)

National Weather Service report on the 6/29/12 derecho

http://www.nws.noaa.gov/os/assessments/pdfs/derecho12.pdf



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