On Monday afternoon, the National Weather Service declared a one out of five “marginal risk” warning. They did not predict that a 100 mile per hour wind derecho would leave over 200,000 citizens in Iowa bereft of power. A derecho is a spanish term meaning “straight ahead,” and is defined as a line of intense fast-moving, damaging windstorms occasionally accompanied by thunderstorms. This type of environmental disaster is notoriously rare and difficult to predict. Although the average wind speed in these straight line storms is 50 to 70 mph, this derecho was particularly fierce, with a record 110 mph, resulting in hurricane force winds in Iowa.