On Wednesday July 9th, 2008, during the mid evening hours, a mayfly hatch occurred in the La Crosse, WI area sending thousands (millions?) of bugs into the air. These hatches are typically caught by National Weather Service Doppler Radar out of La Crosse and Wednesday's hatch was no exception. The image below was caught around 9:40 p.m. CDT on Wednesday evening. The light radar returns (green and blue colors) show up along the Mississippi River valley for a short duration before the bugs leaving the water settle on to nearby trees, buildings, and other objects.