 Some bow echoes in the summer are called derechos, and move quite fast through large sections of territory.On the back edge of the rain shield associated with mature squall lines, a wake low can form, which is a mesoscale low pressure area that forms behind the mesoscale high pressure system normally present under the rain canopy, which are sometimes associated with a heat burst.This kind of storm is also known as "Wind of the Stony Lake" (Traditional Chinese