Line echo wave pattern

A line echo wave pattern or LEWP (pronounced "loop" or spelled out) is the radar signature associated with a multiple-bow serial derecho. Areas hit by the apices of each of the bows often see the worst weather, with the highest winds and very heavy rain, but if the sides of the bows reach enough of an orientation parallel to the derecho's movement, a very long-duration heavy rain event can result, leading to flash flooding. A serial derecho can be in the form of a LEWP or a single, very large bow echo.