Mayfly cloud clogs weather radar
Look. Up there in the sky. Is it a tornado? A hail storm? No, it's Mayflies. A plague of Mayflies. So many, in fact, that they were showing up on national weather radar as a cloud stretching from Winona down into Iowa. Experts call this kind of event, when the bugs morph into adults, an "emergence." And it was over quickly, because adult Mayflies apparently live little more than a day. Check it out the cloud:

Via NOAA
































