Meteorological radar is capable of detecting not only rain or snow clouds, but also more interesting objects like birds and flying fragments of debris during a tornado. But this week a radar «noticed» something truly amazing – a swarm of butterflies with a length of 70 miles.
Caught by the radar of butterflies is called replicati (top photo), and because of the similarity they are often confused with butterflies species monarch (bottom photo). The insects descended on the front range of the Rocky mountains in Colorado. There they fed on the pollen of local flowers and sometimes flew together, like living clouds.
At first the meteorologists thought they were birds, as the insects rarely form «a coherent radar signature», but with migratory birds it happens quite often. After a question on Twitter about what it could be, people started to write about what they saw swarms of colorful butterflies forest, drifting with the wind across the district.
Look at what’s flying into Denver! Radar from last hour showing what we believe to be birds. Any bird experts know what kind? #ornithology pic.twitter.com/EAqzdMwpFU
— NWS Boulder (@NWSBoulder) October 3, 2017
The fact that meteorological radars notice the animals and insects, is just a funny by-product of radar technology, which, however, can bring benefit, by detecting the debris lifted into the air by the tornado. This allows forecasters to pinpoint the level of a tornado and warn people at risk. This especially helps at night with the tornado, masked by the rain when visibility drops significantly.
