Last Saturday evening, local time, a massive mayfly emergence along the upper part of the Mississippi River was caught on weather radars.

These images are from the weather radars at National Weather Service offices in La Crosse, Wisconsin and Davenport, Iowa.

This is not the first time weather radar has caught this phenomenon.  But this particular event produced some very striking images.  Not only do these images indicated the magnitude of the emergence, but you can also see evidence of the south wind that was in place that night as it helped to push the mayflies along.

La Crosse, Wisconsin

Davenport, Iowa

Homepage image/ NOAA

Radar images courtesy of NOAA

By WeatherWatch Analyst Howard Joseph