Butterfly-Shaped "Rain Showers" On St. Louis Weather Radar Turned Out To Be Butterflies

National Weather Service radar in St. Louis, Missouri
captured a butterfly shaped cloud of monarch
butterflies passing overhead on their
migration to Mexico.  

A really awesome and cool "weather disturbance" of sorts passed over the St. Louis, Missouri metro area last week, the web site CityLab reports.

National Weather Service radar in St. Louis showed what looked to be showers, or tornado debris, or something, constantly changing shape as it moved southward toward Mexico.

All other indications showed there were no storms or weather disturbances that could cause rain, tornadoes or anything else of note in Missouri. It was a really nice day.

For awhile, the "disturbance" heading toward Mexico took on the shape of a giant butterfly over  St. Louis and most of its suburbs.

It turns out the radar was picking up a giant flock of monarch butterflies migrating south toward Mexico.  The monarchs were really cool and thoughtful, in my opinion, to fly in the formation of a giant butterfly as they headed south.

Monarchs that live in the summer east of the Rocky Mountains fly to a specific mountain area in Mexico, where they hang out in oyamel fir trees for the winter. (They can't survive the cold winters in most of the United States.)

They also reproduce over the winter in Mexico, and the next generation of monarchs fly north for us to enjoy each spring.

That such a large number of monarchs is a good sign, as CityLab notes. Habitat loss, extreme weather and possibly pesticides have decimated the numbers of these beautiful butterflies, so here's hoping this radar image shows they're hanging in there.

Or maybe their dwindling numbers appeared on the radar to tell us to do things to protect them and let their numbers recover.