LYNXVILLE (WKOW) – Mayflies were spotted swarming above the Mississippi River Monday evening and the phenomenon could be seen on radar.
Officials with the National Weather Service in La Crosse noticed the feature from around 9:15 pm to 10 pm and posted on Facebook about it.
The reflectivity shows a line of green following the topography of the river. The sudden plume of brighter colors indicates that hatch.
The swarm extended at least 50 miles from Onalaska, WI down towards Lynxville.
Mayfly hatches can occur from the spring to fall around dawn or dusk. The bugs only live for about a day and swarm above bodies of water to mate.