"To write well and worthily of American things," said Henry James, "one needs, even more than elsewhere, to be a master." Weather Eye, of course, has no such magisterial pretensions, but it is as true in meteorology as in other disciplines that America is different. Weather phenomena are bigger, more spectacular and potentially more dangerous. The derecho provides a case in point.
If the term is unfamiliar, there is nothing new about the derecho itself. As 19th century settlers trekked westward across the plains, the "great blow of the prairie" - and the fears that it induced - were legendary.
During the 1880s, Gustavus Hinrichs, then director of the Iowa Weather Service, coined the name by which it is still known.
The word has its accent on its second syllable: it is pronounced "day-RAY-cho", like "tornado" or "lumbago", and not, as one might think, like the biblical city whose walls came tumbling down. It comes from a Spanish word which means both "right" - as in derechos humanos , human rights - and "straight".
In the latter guise, it has become in meteorology a "straight-line windstorm" - a long ribbon of storm-force winds that occurs when dozens of thunderstorms arrange themselves in a line, which may be several hundred miles in length, to perform a tempestuous, destructive version of the linedance.
Thunderstorms arranged like this combine to acquire an awesome synergy. The strong winds have their origin in the vicious "downbursts" that are a characteristic of a thundercloud - strong jets of air that surge earthwards through the cloud's core and which, when they hit the ground, spread radially out in all directions similar to a jet of water from the tap when it encounters the bottom of the kitchen sink.
It is not uncommon for a derecho to produce winds in excess of 100 m.p.h.; it cuts a swathe of damage across a landscape perhaps 800 miles in length and more than 150 miles in width, during a lifetime of some 16 hours or more.
To make matters worse, most derechoes also spawn tornadoes - destructive as always, even if their existence is difficult to detect in the surrounding mayhem.
Statistics suggest that some 15 to 20 derechoes surge through the Midwest of the United States every year during late spring and summer. One of the most destructive of recent times occurred 10 years ago today, hitting Wichita in Kansas on June 19th, 1990. Winds of 116 m.p.h. were recorded - as strong as many a tornado. It felled trees, ripped many buildings apart, toppled more than 1,000 electricity poles and caused, in total, more than 50 million dollars worth of damage.